Talk:Greenhouse gas/Archive 1

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Contents

Natural/anthro GH/emissions

(William M. Connolley 23:07, 23 Feb 2004 (UTC)) Can this really be the first talk? So it is...

MrJones made 2 mods:

Greenhouse gases are gaseous components of the atmosphere that contribute to the greenhouse effect, believed to be the major cause of global warming.

This appears to confuse the natural GH effect and the added anthro effect. The original (reverted) was better: it omitted discussion and said just "see also GW". User:William M. Connolley

How is it confusing, sorry? How is the differentiation of human and natural emmisions relevant to the definition? And how does the original text make that distinction? I was just flagging up that not everyone believes that global warming and the greenhouse effect are the same thing.
(William M. Connolley 09:27, 24 Feb 2004 (UTC)) The original text doesn't make the distinction. It doesn't even raise the issue, except to shuffle it off into "see also GW". Which, I assert, is a good idea. Your text says: "contribute to the greenhouse effect, believed to be the major cause of global warming". This is easily read to say that all the GHG's do (in sum) is to cause GW.

Mr. Jones 08:07, 24 Feb 2004 (UTC)

The major natural greenhouse gases are water vapor, constituting most (about 60%) of such gasses on Earth, others being carbon dioxide (about 26%), and ozone. The remaining fraction, believed to have minor effect include methane and nitrous oxide. These gasses are so-called because they are widely believed by scientists to cause the greenhouse effect. However, not all agree.

Again, this is confusing natural and anthro GH. No one (no one at all? well certainly no one of any repute) argues that "these gases" cause the GH effect. User:William M. Connolley

Do you mean "do not cause"? How about "not all agree that the effect is significant, controllable or cause for concern?" Mr. Jones 08:07, 24 Feb 2004 (UTC)
I mean, no-one argues about whether they cause the (natural) GH effect or not: everyone agrees that they do. Your text contradicts this: it asserts that "not all agree" that these gases cause the GHE. User:William M. Connolley
Yes, sorry that was an unfortunate choice of words. What do you think of "not all agree that the effect is significant, controllable or cause for concern?"
(William M. Connolley 13:00, 24 Feb 2004 (UTC)) No. Because everyone *does* agree that the *natural* GH effect is significant. You need to distinguish very carefully between the natural GHE, which is significant (about 33 oC) and accepted by everyone, and the anthro effect, which is (mysteriously) more controversial.
Ah! Light dawns. :-) I'll see if I can explain this distinction in the article in a little while. If I got it wrong, I suppose others will too.

Mr. Jones 14:35, 24 Feb 2004 (UTC)

I also suggest putting " (see also global warming for the debate about its significance) ". How's that? Mr. Jones 12:45, 24 Feb 2004 (UTC)
Ditto my comments above.
" (see also global warming for the debate about the proportion of the atmospheric greenhouse effect attibutable to humans) "?
" (see also global warming for the debate about the possible recent increases in the atmospheric greenhouse effect) "?

Mr. Jones 14:35, 24 Feb 2004 (UTC)

(William M. Connolley 15:17, 24 Feb 2004 (UTC)) Why not the original "(see also GW)". Do you regard that as non-neutral?
Omission of assertions and failing to clarify assertions can be as misleading as false assertions. I'm not decided whether that's relevant here yet. Do you believe refering to the debate is not NPOV? Mr. Jones 19:22, 24 Feb 2004 (UTC)

If at all possible, let's keep the GW fighting on the GW pages. User:William M. Connolley

Oh, certainly. I wasn't fighting as such, just trying to move the article closer to NPOV.Mr. Jones 08:07, 24 Feb 2004 (UTC)
Doc, if you concede that you're fighting, maybe it's time you changed your tune. Why not start doing the NPOV dance? Try it, you'll like it! --Uncle Ed 17:56, 24 Feb 2004 (UTC)

(William M. Connolley 18:27, 24 Feb 2004 (UTC)) "Fighting" is just shorthand. If you've failed to understand me, then I'll try to expand: There are plenty of issues about GW, but these are best discussed on the GW and related pages. Stuff about GH effect is probably better on the... GH effect page. Odd, no? There is no need for the GHG page to be controversial. Or is there?

Right, I think I see what you're getting at. I don't think it needs to be controversial, as such. However, being a topic proximate to and refering to a controversial one it seems a little odd not to explain it, as that is most likely what is in the reader's mind. Mr. Jones 19:22, 24 Feb 2004 (UTC)


LOL, I knew what you meant; I just didn't want to lose a chance to rib you a bit... But, seriously, GHG is controversial because the press often confounds 2 types of greenhouse gases: those which keep us from freezing to death and those which "contribute to global warming". --Uncle Ed 18:30, 24 Feb 2004 (UTC)
(William M. Connolley 18:37, 24 Feb 2004 (UTC)) Well yes - this is the somewhat what I've been discussing above with MrJones. Although you're wrong, of course, to say there are 2 types of GHG: all GHGs contribute, to both. Its just that the extra effect from the extra concentration of the gases is more controversial. Perhaps you've been reading too many press reports?
Chemically they are identical, but being from different sources aren't they different? A polo mint made in Russia and one made in China are not of the same type, although one may well not be able to tell them apart by analysis: one is Russian and the other Chinese. Mr. Jones 19:22, 24 Feb 2004 (UTC)
(William M. Connolley 21:04, 24 Feb 2004 (UTC)) The CO2 *perturbation* is anthropogenic but the reservoir exchanges are large, so knowing whether a given molecule is "natural" or "anthro" doesn't help.

WV forms clouds

(William M. Connolley 18:57, 24 Feb 2004 (UTC)) Ed: when you say WV forms clouds, do you mean clouds are composed of WV, or that clouds are made (by transformation) out of WV?

"Whose likeness is upon this coin? ... Then render unto Caesar that which belongs to Caesar." (C'mon, doc, you know the answer better than I do.) --Uncle Ed 14:41, 25 Feb 2004 (UTC)


(William M. Connolley 15:46, 2004 Feb 25 (UTC)) It doesn't really matter now, since I deleted that whole section :-)

Sources for wv, co2, etc contributions.

(William M. Connolley 21:10, 15 Jan 2005 (UTC)) Cortonin added some numbers from the clearlight page http://www.clearlight.com/~mhieb/WVFossils/greenhouse_data.html. I think those numbers (or at least the wv one) is/are junk. The source for the ones on this page is given on the greenhouse effect page, BTW.

So, why do I think the CL number for WV is junk? If you look at the CL page, it eventually sources the 95% claim to http://www.co2andclimate.org/climate/previous_issues/vol4/v4n4/focus1.htm. This is a dodgy source in itself, but reading on we find that the actual claim is:

Washington also challenges some of Singer’s facts. Where Singer states that water vapor accounts for 95 percent of the greenhouse effect, Washington claims this number should be close to 65 percent. While the difference seems large, it is really only a matter of semantics. Water vapor might only account for 65 percent, but atmospheric water droplets (i.e. clouds) make up the other 30 percent.

The 65% figure is close to the 60% in the article (and I doubt that the real number is known that accurately, as it varies by location) and the adding in an extra 30% for clouds is just weird. That means that the true source for the 95% claim is Singers book: Singer, F.S., 1998, Hot Talk, Cold Science: Global Warming’s Unfinished Debate, Oakland, Calif.: The Independent Institute. which is again a dubious-at-best source (I've never read it, mind you).

I don't think calling sources dubious because you haven't read them is a particularly productive approach. The greenhouse effect article that you refer to ranges estimates from 60-70, up to 88, and even 98% depending on which factors are considered. The 60% value is arbitrarilly selecting the lower bound of the 60-70% value which completely excludes clouds. Clearly, excluding clouds is not a realistic system, and the actual value must be significantly higher than that range when clouds are included. I converted the value in the opening paragraph into a range, according to the documentation presented. — Cortonin | Talk 05:32, 16 Jan 2005 (UTC)
(William M. Connolley 10:50, 16 Jan 2005 (UTC)) Read it again, the 98% value is not a realistic one. Including clouds within WV is silly: clouds *aren't* WV. The CL page is junk, and not a source. Its just some random bods page. If you want to source the 95% value, you can't use CL, you would have to go back to quoting Singers book, which is CLs source (although it takes some tracking back to discover that). But Singers book isn't a source either: you would need to read that to discover where he go his 95% figure from. Made it up, probably.
By that page is "junk" do you mean not your point of view? What specifically is "junk" about it besides you disagreeing with it? — Cortonin | Talk 20:09, 16 Jan 2005 (UTC)
I will include a compromise which mentions clouds explicitely. Using only a value from a model which excludes the existence of clouds, and failing to mention that to the reader, borders on dishonesty. When in doubt, it's better to provide more information and let the reader draw appropriate conclusions. — Cortonin | Talk 20:09, 16 Jan 2005 (UTC)
From the IPCC page on water vapour feedback: "Furthermore, water vapour feedback acts to amplify other feedbacks in models, such as cloud feedback and ice albedo feedback." "Incorporating cloud radiative effects and a fixed relative humidity perturbation (argued to be most appropriate to diagnosing GCM water vapour feedback)" — Cortonin | Talk 20:09, 16 Jan 2005 (UTC)
I have also corrected the 60% value to 60-70%, which matches the other wikipedia article it supposedly came from. — Cortonin | Talk 20:09, 16 Jan 2005 (UTC)
(William M. Connolley 21:43, 16 Jan 2005 (UTC)) 60-70% you're welcome to. CL is junk because its some bods personal research based on plucking a figure of 95% out of some book review he read. Including clouds is wrong *because they aren't a GHG*. They aren't even a gas, in fact.
Pop quiz: Where do clouds come from? That's right, condensation of water vapor. The problem begins when the paragraph states "causes 60-70% of the greenhouse effect on Earth", since clearly that's a lie. Clouds are a rather significant component of the greenhouse effect, and they're not included in that calculation. — Cortonin | Talk 21:18, 17 Jan 2005 (UTC)

(William M. Connolley 21:50, 17 Jan 2005 (UTC)) OK, progress. Clouds aren't a greenhouse gas. If they belong anywhere, then, they belong on the greenhouse effect page. Now, as to your "lie" stuff, try to be a bit more polite. The source of your figure for the cloud effect is quite unclear. Clouds make a +ve and -ve contribution to the radiative balance, and their overall contribution is a small negative effect (source: IPCC tar). So what is your source for the approx 30% value you quote?

The 88% comes from the greenhouse effect page. The 95% comes from the source you keep erasing. It's appropriate to place it as a range, especially considering the accepted uncertainty in the contribution of clouds. Specifically, the IPCC tar which you love to invoke, states, "The potential complexity of the response of clouds to climate change was identified in the SAR as a major source of uncertainty for climate models. Although there has been clear progress in the physical content of the models, clouds remain a dominant source of uncertainty" [1]. Your certainty about these values does not match the assessments of others. The statement belongs on this page, because this page starts off with incomplete statements about the contributions of certain greenhouse gases to the greenhouse effect. Clouds exist, and they're part of the greenhouse effect. Pretending they don't exist does not make a number more accurate than numbers which attempt to include them. It IS deceptive to keep erasing other values from other sources when the values presented represent an oversimplified model. So if it's "polite" you're looking for, then how about you stop reverting every contribution I make, because that's pretty darn impolite. — Cortonin | Talk 01:39, 18 Jan 2005 (UTC)
(William M. Connolley 10:00, 18 Jan 2005 (UTC)) The CL page is junk, as I explained above, which means you have no source at all for the 95% value. The 88% value which you've plucked from the GHE page is for WV and CO2 only, so can't be used as is, and is from Soon and Baliunas anyway, who don't have the expertise to calculate this themselves anyway. This is the *GHG* page, any discussion of effects from things that aren't gases belongs no the GHE page. And as I said, clouds are a small net *negative* forcing, not a positive one as you seem to believe. Yes indeed, the cloud forcing is a source of uncertainty, but the value you give from whatever mysterious source is quite unreasonable.
Clouds also play an important role in the Earth’s energy balance and in particular in the natural greenhouse effect. Clouds absorb and emit infrared radiation and thus contribute to warming the Earth’s surface, just like the greenhouse gases. On the other hand, most clouds are bright reflectors of solar radiation and tend to cool the climate system. The net average effect of the Earth’s cloud cover in the present climate is a slight cooling: the reflection of radiation more than compensates for the greenhouse effect of clouds. [2]

(Editor @ 129.186) - I'm sorry if some of you are upset with what I added, but I think water vapor's huge role as a greenhouse gas is *seriously* toned down in this particular article. I would agree with the "impossible to determine the full impact of a particular gas" vibe you're suggesting for both water vapor and CO2, but there are some clear impacts that water vapor has on the greenhouse effect that make it impossible to simply discount it as an insignificant role in the greenhouse effect compared to CO2.

(William M. Connolley 21:55, 16 Feb 2005 (UTC)) See http://mustelid.blogspot.com/2005/01/water-vapour-is-not-dominant.html (I wrote it).
How about you see "Water vapor is the dominant greenhouse gas" (link updated). I didn't write it, but it is published and certainly trumps your personal blog. — Cortonin | Talk 14:04, 21 Feb 2005 (UTC)
Try this link [3] as the one above returns a "cookie error". This is just to the abstract, I don't have access to the full article. I find the following quote interesting: " To the extent that water vapor concentrations increase in a warmer world, the climatic effects of the other greenhouse gases will be amplified." -Vsmith 14:35, 21 Feb 2005 (UTC)
Another abstract by one of the above authors: [4] with a bit of different info. Vsmith 14:43, 21 Feb 2005 (UTC)

(William M. Connolley 14:58, 21 Feb 2005 (UTC)) I too get cookie errors from C's link. But I've read both the abstracts. They don't "trump" my blog, because they are not talking about the same thing. There are subleties here that you need to pay attention to. I do agree with what they say though, in particular:

Water vapor is the dominant greenhouse gas and provides the largest known feedback mechanism for amplifying global warming. As the concentrations of other greenhouse gases increase due to anthropogenic activity, it is centrally important to understand the radiative response of water vapor to this forcing. All models currently predict a strong positive feedback from water vapor, arising from the exponential increase in saturation vapor pressure with temperature.

Words like that are fine for scientists, who known that "dominant" in this case means "largest". What my blog explains is that it doesn't mean "dominant" in the sense of being the forcing you need to worry about. As the quote above makes clear, you need to consider WV *as a feedback* which amplifies the CO2 etc warming. Notice, incidentally, how this abstract takes GW as a given - as do so many others - not as a thing to quibble about.

Words like that are fine for anyone who speaks English. It doesn't make much sense to keep putting forth that straw man (see rhetorical term paragraph) about dominant being used to refer to forcing. Of primary concern is trying to describe which greenhouse gases contribute the largest amount to the greenhouse effect, which alone has nothing at all to do with forcing. What you're implying is that when describing the gun, we shouldn't mention the bullet, because the trigger is what makes it fire, and that it will confuse people too much to mention bullets. What's most important in an encyclopedia article is describing what exists and what mechanisms there are, because mechanisms outlast and are more constant than forcings. Water vapor is clearly the dominant greenhouse gas, and your straw man should at best be included as a qualifier stating that CO2 is a more dominant forcing agent, and perhaps referencing the climate forcing article. — Cortonin | Talk 15:16, 21 Feb 2005 (UTC)
(Editor @ 129.186) - I would tend to agree. I find it ridiculous that in an article about greenhouse gases that water vapor, which is always listed among C02 & Methane, would somehow be downplayed. If our role is to simply list the greenhouse gases on this page and not to edcuate the reader then two things about this article bother me: 1) the page spends far too much time centering on the negative aspects of the other greenhouse gases, 2) a 1990 IPCC report about the role of water vapor is the most recent source for this area. There are still ways for you to push the global warming agenda in this article by citing from numerous studies that claim El Nino was an effect and not a cause of rising global temperatures.
(William M. Connolley 16:17, 2 Mar 2005 (UTC)) The reason that 1990 IPCC data are used is that nothing better is available. This is a clue. The answer is: no-one is terribly interested in quantifying the exact numbers, since they really don't matter much, *since WV is a feedback not a forcing*. Another modeller I know has run some calcs using a current GCM, and removing various forcings instantaneously. He gets numbers very similar to IPCC '90. As for "downplaying" WV... the intro says The major natural greenhouse gases are water vapor... - what more do you want?
(Editor @ 129.186) - Well, for starters, how about putting in the quote you listed above? Water vapor is the dominant greenhouse gas and provides the largest known feedback mechanism for amplifying global warming. You could even go on to define "dominant" as per your blog. I just find it ironic that it's supposedly impossible to argue the merits of water vapor on the GHE, yet there are those that claim to have models explicitly accounting for temperature increases due to C02 emissions. It doesn't make sense.
(William M. Connolley 17:48, 2 Mar 2005 (UTC)) I'm not sure what you mean. The page says, correctly, that you cannot say gas X causes Y percent of the effect, and explains why. That doesn't mean models can't combine the effects correctly.
Why I even made a change in the first place is what appears to be a complete disregard of water vapor's role,
(William M. Connolley 17:48, 2 Mar 2005 (UTC)) Err, you *have* noticed the section called "the role of WV" haven't you?
and/or an explanation of how it is being manipulated by increases in CO2. I understand there is still some debate as to how and how much, but the whole reason I came to this article to begin with was to learn more about that specific aspect of climate modelling with respect to GHG. Maybe the GHG page isn't the best place for an explanation, however.
(William M. Connolley 17:48, 2 Mar 2005 (UTC)) OK... I'll edit the section called role-of-WV and you see if it looks any clearer.

I think part of the difference of opinion here is that you (WMC) are editing from the perspective of greenhouse gases only being relevant from the perspective of explaining global warming. This is apparently the perspective of Michael Mann as well, given his quote about listing water vapor as a greenhouse gas as being "misleading". But this ignores an entirely different perspective of greenhouse gases, which is that greenhouse gases and the greenhouse effect predate humanity's existence by quite a few orders of magnitude. Greenhouse gases are an important natural phenomena, regardless of global warming, and this should be their first mention (since their natural function comes first in logical order before describing changes to them). Then what should be explained is the changes humans seem to have made to greenhouse gas levels, and then include the proposed feedback mechanisms which are thought to also change greenhouse gas levels. In particular with water vapor, its primary contribution seems to be that it helps keep us from freezing to death, and then the feedback mechanisms should also be described as an important role for understanding the potential impact of changes to greenhouse levels. — Cortonin | Talk 23:32, 2 Mar 2005 (UTC)

Cortonin put the nail on the head. Maybe my problem is with the organization. I understand that there is debate on this subject, but leading with "Anthropogenic greenhouse gases" over WV is confusing to someone doing a high school research paper, or just wanting to understand the science. Sure, get into the debate, but first establish what it is. GW debate aside, the greenhouse gases and greenhouse effect are naturally occurring phenomenon, and that doesn't seem to be established well in this article. I would seriously question the motives of ignoring water vapor's role altogether as Michael Mann suggests. That is clearly hijacking the term "greenhouse" (added with "gas" or "effect") for the purposes of pushing an agenda. Negating the natural greenhouse effect and defining the terms as solely attributable to human conditions and causes is nothing short of misleading and unethical. I don't know if I'd even consider Mann's comments worth noting, as they could be marred similarly (and quite easily) in the same fashion that Schneider's comments were taken out of context.
(William M. Connolley 09:57, 8 Mar 2005 (UTC)) Errr... here's a test: which is the first GHG mentioned on the page? How is it described? Is that description appropriate to something causing approx 60-70% of the GHE? As to the first section being about anthro gases: this is entirely reasonable, as that probably why most people are on this page.


Dispute Resolution RFC, William M. Connolley

I started an RFC regarding user William M. Connolley, located here: Wikipedia:Requests for comment/William M. Connolley. If you are interested, please comment or sign as appropriate. — Cortonin | Talk 12:28, 18 Jan 2005 (UTC)

The question of spelling (Vapor/Vapour)

1. Water vapour is the spelling in the IPCC report and there is no sense changing it to US spelling. Appears just a snub. or were you wanting a spelling war?

The IPCC report's spelling is irrelevant for the purposes of this article. The individual in question is American, so I think it is confusing to have a discussion of his claims using non-American spelling. It creates the false impression that he is British.--JonGwynne 01:13, 28 Jan 2005 (UTC)
This is hilarious! A few days ago I looked at this article and saw inconsistency in the spelling of vapour/vapor. I decided to make it consistent and as the dominant spelling was vapour I went with that, even tho' I'm an American and personally prefer the other. Then JG arbitrarily changes them all to vapor. The article was written by a group of people - not by this American he refers to. There is no false impression - just an obvious snub at the British writers involved in writing this article. Vsmith 02:25, 28 Jan 2005 (UTC)

2. Don't know the basis for your normalizing - is this original research? I can decifer the math you used - don't know the significance.

The math is quite simple, multiply the increase by the GWP factor to see what the equivalent in CO2 would be. It helps put the changes in perspective. I wouldn't call it "original research", it is basic math. But if you want to leave it out, I don't mind.--JonGwynne 01:13, 28 Jan 2005 (UTC)

3. The secondary percent by volume numbers really don't add anything, just an attempt to add clutter and make the numbers look insignificant or something. Not needed - probably just POV attempt to minimize or trivialize the values.
-Vsmith 00:39, 28 Jan 2005 (UTC)

Well, that's your POV and you're welcome to it. But the current one-sided percentage increases are also POV so either we do both or neither. Which would you prefer? Since you seem to be worried about clutter, I'll start with neither as the baseline and then we can discuss it from there--JonGwynne 01:13, 28 Jan 2005 (UTC)

Deceptive edit summary again. (Cleaned up for Vsmith) is not what you did. Vsmith 02:44, 28 Jan 2005 (UTC)

(William M. Connolley 09:36, 28 Jan 2005 (UTC)) I've added it to Wikipedia:Requests for comment/JonGwynne.


There are 1.82 million google hits for "vapour", and 7.24 million google hits for "vapor". Given that this is the internet, I believe it would be most appropriate to use the spelling which is most common, and in this case it is quite dominantly "vapor". (Dictionaries determine which spelling to list first by assessing most common usage, so this is the most appropriate method of deciding spelling preference.) — Cortonin | Talk 05:03, 28 Jan 2005 (UTC)

(William M. Connolley 09:30, 28 Jan 2005 (UTC)) Wiki has a policy designed to avoid spelling wars, and is *isnt* count the google hits.
Reference? — Cortonin | Talk 15:14, 28 Jan 2005 (UTC)
(William M. Connolley 18:01, 28 Jan 2005 (UTC)) You'll find it at: Wikipedia:Manual_of_Style#Usage_and_spelling
Well, in the case of a topic without a particular regional focus it doesn't really offer a lot of advice for "choosing" a spelling preference, it simply instructs people to try to avoid edit wars on the topic by just sticking with what's there. At this point in this article, "what's there" is a bit in flux as far as spelling preference, and this is why I suggested using the google counting method. — Cortonin | Talk 12:15, 29 Jan 2005 (UTC)
Here's what I think is the overriding factor: The article makes reference to another wikipedia article called "Water vapor". The spelling in this article should conform to the other one so it isn't necessary to kludge the links to it and so there won't be any confusing if a reader wants to jump from this article to the other one. So, with that in mind, I'm going to change this article's spelling to "vapor" for reasons of consistency.--JonGwynne 21:18, 28 Jan 2005 (UTC)

OK. Since JG doesn't seem to want to read the Manual of style referenced above (or else he simply decided to ignore it), here is the pertinent section: If an article is predominantly written in one type of English, aim to conform to that type rather than provoking conflict by changing to another. (Sometimes, this can happen quite innocently, so please don't be too quick to make accusations!). As stated above, on Jan 23 I corrected the spelling inconsistency and changed all vapor spellings to vapour which was the dominant spelling on the page. JG persists in reverting to vapor while inventing his own style guide. As this quite obviously was not an innocent mistake I can only assume that he is trying to pick a fight by starting a British/American spelling edit war. I feel this combative, in your face editing attitude should be added to the comments on the RFC Wikipedia:Requests for comment/JonGwynne. -Vsmith 00:00, 29 Jan 2005 (UTC)

Let me see if I can explain this again. The reason I changed it was to create consistency with the article on the subject of water vapor. Why should the article have one spelling and the references to it use the other. It is confusing and inconsistent and so I fixed it. If the original article was entited "water vapour", then that's the spelling we should have used in this one. This was nothing to do with me, I didn't write the article on water vapor. Your assumption that I am "trying to pick a fight" by introducing consistency is simply absurd.--JonGwynne 03:20, 29 Jan 2005 (UTC)
(William M. Connolley 10:57, 29 Jan 2005 (UTC)) I support Vsmiths interpretation. JG, stop picking fights for no good reason. If you've got science to add to the article, do, otherwise go do something more productive.
The only person picking a fight here William is you. You're the one who runs off to the RFC to catalog your laundry-list of imagined grievances. Vsmith's interpretation is irrelevant since it fails to consider the overriding factor that I will spell out a third time since it seemes to slip right past you the first two: there is already an article on water vapor. Do you understand that? I'm simply using that article's spelling for the sake of consistency. Does that seem clear to you?--JonGwynne 12:51, 29 Jan 2005 (UTC)
Stop the phoney nonsense: the 1st and 2nd time you changed it it was stated as Americanizing, the third was hidden in a deceptive edit summary, then when that didn't work you decided to use the consistency theme because of an invisible vapor in a link. You are simply provoking a conflict. -Vsmith 14:04, 29 Jan 2005 (UTC)
The only "phoney nonsense" here is what you're bringing. While you are correct that the first time I changed it, my intent was to make it consistent with the writings of the man whose work was being referenced, I had no objection to it being switched back as it was clear that this wasn't sufficient grounds for the change. I was fine with that. However, upon reconsidering the issue, it became obvious to me that the overriding issue here is the wikipedia article on water vapor. It simply doesn't make sense to use one spelling in the original article and a different spelling in an article which directly refers to it. Just because you are unable to admit when you're wrong doesn't mean you are entitled to suject the rest of us to this nuisance reversion. In case you need further clarification, look at the original page's links to the water vapor article. Whoever it was who added them had to go the trouble of creating the kludged links "water vapor|water vapour" in order to preserve the inconsistent spelling. There are other examples of articles with the "vapor" spelling - vapor & vapor pressure to name just two. In this situation, I'm right, you're wrong and the sooner you can come to grips with that fact, the sooner we can get back to more important things. --JonGwynne 17:28, 29 Jan 2005 (UTC)

Parts-per spelling

While on the grand scheme of things "vapor" versus "vapour" doesn't really matter so much, you've all glazed over one thing that really does matter. Amidst this revert war, we seem to have some changes to ppvm and ppvb being changed back and forth, which perhaps may be related to the different usage of "million" and "billion" across the pond. More importantly than which one we use is that we need to clarify what it actually means numerically. My suggestion is that someone who knows which version is correct under which interpretation of million/billion should place a description of what that actually means in terms of a power of 10 somewhere shortly beneath the first usage. — Cortonin | Talk 12:15, 29 Jan 2005 (UTC)

As far I know, 1000ppvb = 1 ppvm. Does anyone here disagree?--JonGwynne 12:51, 29 Jan 2005 (UTC)
I think whichever unit is used, it makes sense to use the same units rather than some ppvm and some ppvb. Just as we try to be consistent with temperature units, despite K/C/F. (I see carbon dioxide uses ppmv and there is Talk:Carbon_dioxide#Why_not_ppm? about it there also. Concentration#"Parts-per"_Notation says usually ppmv (note at bottom of section); the NIST link suggests using powers of 10. However, the IPCC Units states ppmv (parts per million (106) by volume) or ppbv (parts per million (109) by volume). IPCC TAR mostly uses ppmv and has only a few references to ppbv. The NIST does note that terminology used in laws should be followed, and in nations which are part of the UNFCCC then the IPCC terminology could be seen as a "law". SEWilco 06:23, 5 Feb 2005 (UTC)

Spelling Resolution Proposal

Will you two stop fighting over the spelling of vapor/vapour if we take a vote on it? I'd like if both of you could agree to abide by the result of the vote. We can give it, say, a week of time for people to vote. Can we get an agreement to this from both of you? — Cortonin | Talk 10:16, 31 Jan 2005 (UTC)

I suggest that we abide by the Manual of Style which JG is ignoring. See my comments above (and read them carefully). What you are suggesting is a loaded popularity contest based on your Google search. _Vsmith 12:47, 31 Jan 2005 (UTC)
(William M. Connolley 12:57, 31 Jan 2005 (UTC)) Ditto.
No, I'm suggesting a simple vote of the existing Wikipedia editors to establish a wiki-consensus to avoid and eliminate a rather meaningless conflict. Does that sound so bad to you? — Cortonin | Talk 18:08, 31 Jan 2005 (UTC)
I am strongly opposed to a vote. The policy on this is clear; the page was standardized on British spelling, JG Americanized it twice. After having the policy pointed out to him, he used another rationalization that was also incorrect to continue reverting. A vote would partially validate this bad behavior, and the page doesn't need any more controversy. I know that JG is new to Wikipedia but the policy has now been explained to him. I will consider any further reversions to American spelling as vandalism, trolling and disruption. I have no vested interest in editing this page, other than to honor the manual of style. Duk 20:11, 31 Jan 2005 (UTC)
(William M. Connolley 21:23, 31 Jan 2005 (UTC)) The policy is indeed clear, and was designed at least in part to prevent wars of this kind. Cortonin has had this pointed out to him. As for JG, if you haven't seen it, you might care to view Wikipedia:Requests for comment/JonGwynne (and the associated one for me, of course).
I tried to resolve the matter, but if you wish to continue in conflict, I hope you enjoy it. — Cortonin | Talk 01:14, 1 Feb 2005 (UTC)
Cortonin, how can we work on resolving conflicts if we don't observe simple rules? If someone wants to change the spelling on one page to match other pages, they have a conflict with the manual of style. That is where this conversation belongs. Duk 03:53, 1 Feb 2005 (UTC)
You mean like the style guide which says "the original contributor's usage should be followed."? Perhaps you could look at the first [5] two [6] years [7]. In fact, up until just this past October [8], the dominant spelling was "vapor". Until someone [9] (namely WMC) started converting the spellings over to "vapour". And in fact, despite this, if you look at just one month ago [10], you will see that the spelling was still 8 to 3 in favor of "vapor", the original spelling of the article. Then Vsmith came along here [11] only 9 days ago, and converted the dominant spelling "vapor" into "vapour", in violation of the style manual's instructions. So if you REALLY wanted to obey the style manual, you would just put all the spellings back to "vapor" to match the original usage in this article, and end this ridiculous edit war (since you obviously didn't like the idea of a vote). — Cortonin | Talk 05:32, 1 Feb 2005 (UTC)
Cortonin, I am sorry, haven't done the homework that you have done. If you are right, and the article was incorrectly changed from prodominantly American to British spelling recently, then I apply exactly the same criteria as if it were the other way around. Thanks for mentioning this. Duk 12:16, 1 Feb 2005 (UTC)
(William M. Connolley 12:34, 1 Feb 2005 (UTC)) I certainly agree we should be following policy, so lets check carefully before we do any more reverts on this. I'm happy to accept the "original" spelling, if that can be determined. However, we need to be careful about accepting Cortonins words at face value. I don't think I've converted any instances of vapor to vapour (at least before the recent war), and the link Cortonin provides demonstrates exactly that.
Looks as though I was in error on Jan. 23, should have done the detailed checking that Cortonin did back then. My apologies for that part. I'd best go undo my error. -Vsmith 12:54, 1 Feb 2005 (UTC)
Ok, I did some more homework; I think Cortonin made good points. The article started out with American spelling. The first British spelling was added four months later (more than a year before WMC started editing it). From then on it contained a mixture of the two (I haven't verified every edit). Eventually, on January 23, Vsmith standardized it from mostly American spelling to British spelling. If this summary is accurate then I think Vsmith should re-standardize it to the American spelling Duk 13:03, 1 Feb 2005 (UTC)
Done. Again, my apologies for not checking closer and/or my inability to count :-) -Vsmith 14:31, 1 Feb 2005 (UTC)

Thank you all for resolving the matter. WMC, please try to avoid statements like, "we need to be careful about accepting Cortonins words at face value." For that matter, you should even try to avoid thinking like that. This is directly counter to Wikipedia policy of "assume good faith", and an entirely unnecessary statement when my statements are well documented, on either simple matters as this one, or on more complex matters involving article topics. — Cortonin | Talk 19:30, 1 Feb 2005 (UTC)

(William M. Connolley 20:41, 1 Feb 2005 (UTC)) You accused me of changing the spelling. That accusation was wrong, and demonstrably so, by the very edit you referred to. Have the grace to admit your mistake.
You started a category called "The role of water vapour" in an article with a dominant spelling of "vapor". This very well may have been unintentional, as I know I don't check for which continent the spellings are from in an article before I begin typing. But my only point was that it wouldn't be correct to conclude that the spelling "vapour" was original or dominant in the article, and thus, this edit war should never have occurred. At the very least, such things should be checked before starting an edit war over it. Examine and consider validity with assumption of good faith first, and ONLY then if an edit can't be worked with should you revert. — Cortonin | Talk 02:29, 2 Feb 2005 (UTC)
(William M. Connolley 21:18, 2 Feb 2005 (UTC)) Oh good grief read your own words: you accused me of started converting the spellings over to "vapour". I did no such thing. You effort to blame me for all the ills of the world makes no sense.
I apologize if you found that offensive, as I said the phrasing was not intended to imply intentionality or guilt, simply primacy of cause and effect. Rather than "started converting the spellings over to vapour" I should have written "created the header with the spelling vapour, probably unintentionally, making that spelling appear more dominant in an article which previously had the spelling vapor." I apologize for my imprecision or any offense. — Cortonin | Talk 21:26, 2 Feb 2005 (UTC)
(William M. Connolley 17:28, 5 Feb 2005 (UTC)) Thanks.

redundant columns in table

The table works, but, don't need the % column with all those zeros. Percent is really pph or parts per hundred and redundant w/ ppm. The sci notation column was just adding confusion and clutter, if a casual reader doesn't grasp ppm values then I doubt they would get the meaning of sci notation either. And those were unitless ... ? Vsmith 16:12, 8 Feb 2005 (UTC)

I agree with you about the scientific notation. Percentages would be better. I disagree with you that the percentage tables are "redundant" though. I realize that 1% is just another way to say pph but not everyone else does. It is both helpful and, in my opinion at least, necessary to put the size of the increase in context by showing what percentage of the atmosphere it represents.--JonGwynne 16:49, 8 Feb 2005 (UTC)
Percentage is not a useful unit to use because you can make no conceptual comparison of a number with a large number of 0's to the left. That's why scientific notation exists. Scientific notation lets you easily compare the relative atmospheric concentrations of each compound, and get a feel for the relative orders of magnitude. This is a standard across all fields of science, and should be used here. ppmv, ppbv, and pptv are less clear for two reasons. First, they are less standard across all fields of science (while they may be standard in atmospheric science, most readers are not experts in this field). Second, the comparison of these values is not immediately obvious, and requires the reader to sit down and try to calculate, since the reader must try to discern the meaning of the change between m, b, and t, and must try to discern whether this results in three left-shifts or three right-shifts of the data. This is unnecessary added confusion when the simple interpretation can be placed right beside those values in terms of an atmospheric concentration expressed in scientific notation. It is standard, clear, and unambiguous. There is nothing to lose by including it. — Cortonin | Talk 15:02, 9 Feb 2005 (UTC)
The problem is that not everyone reading this will be comfortable with scientific notation. For them, the easiest way to compare orders of magnitude are by have the number of decimal places laid out for them. For these people, 0.01 it obviously ten times larger than 0.001. I understand the problem with the large number of zeroes but they can't be avoided with dealing with such small percentages. Maybe two columns, one with sci-notation and one with plain percentages? --JonGwynne 11:37, 10 Feb 2005 (UTC)
Scientific notation is standard in essentially every scientific field and in every country. It's even standard in most high school science educations. Invoking three different classifications of "ppmv", "ppbv", and "pptv", which are sufficiently complicated to the novice to require a decoder chart on the bottom, is just more cryptic and less clear, and is completely unnecessary when the equivalent information can be represented just as easily by scientific notation. It's not important what's commonly used in the field of atmospheric science, since this site is not an atmospheric science paper. The goal is to present the information clearly to a new reader to this topic, and scientific notation does that much more readily. This has nothing to do with POV, this has to do with clarity and simplicity. Please don't waste time fighting against that. — Cortonin | Talk 18:09, 10 Feb 2005 (UTC)

(William M. Connolley 21:20, 10 Feb 2005 (UTC)) The std measure for CO2, and other atmospheric constituents, is ppmv or ppbv. Thats why the chart should give them in this form. Especially since the source of these numbers is the IPCC report, which uses this form.

Which is more important, being the same as the IPCC, or presenting the information in the greatest clarity to the reader? — Cortonin | Talk 21:37, 10 Feb 2005 (UTC)

The Chart

First, the gridlines have to stay in so that it is readable on all browsers. Second, there need to be context columns of some kind to put the increases in an objective context rather than just the subjective context of the IPCC advocates.--JonGwynne 11:37, 10 Feb 2005 (UTC)

What browser are you using Jon? Works fine in Opera and Netscape. The wide grided version conflicted with the image in Netscape. Grid lines - esp. wide ones - are an unnecesary distraction for a short table. Extra columns redundat and not needed, see above discussion, -Vsmith 12:26, 10 Feb 2005 (UTC)
I'm using IE. The chart without lines is unreadable because the columns don't line up. The "extra columns" are not redundant and they are useful information and should stay.--JonGwynne 12:49, 10 Feb 2005 (UTC)
Just checked with IE in school lab (don't have the monster at home:), and the columns line up perfectly. Again refer to discussion above and in the extensive discussion at Talk:Carbon dioxide for your number playing. -Vsmith 16:47, 10 Feb 2005 (UTC)
Dunno what to tell you. It doesn't work for me. Maybe it is the version. Maybe it is my resolution. Maybe it is my video driver. Let me repeat: the chart is unreadable without grid lines. Grid lines aren't a problem so I'll keep putting them back if you take them out. And what's this nonsense about taking gasses stuff out of the chart? This is an article about greenhouse gasses. They're greenhouse gasses. They belong in the chart. If they're important enough for the IPCC to talk about them, they're bloody well important enough for you to leave them in. --JonGwynne 01:55, 12 Feb 2005 (UTC)
OK - keep border @ 1, but there is too much redundancy and too many errors in the other trace gas amounts in your table. I will add corrected data for minor gases later (maybe, after I think on it a bit and have time to sort them out). Right now I'm tired :-) Vsmith 05:29, 12 Feb 2005 (UTC)
I triple-checked the numbers. They are correct. Oh, BTW, I'm removing the reference to Mann's statements about water vapor. Until someone can do better that a political extremist site like commondreams.org repeating a story from the "Environmental News Servive", it can stay on the fringes where it belongs and out of wikipedia.--JonGwynne 01:09, 13 Feb 2005 (UTC)

Updating the numbers

(William M. Connolley 21:44, 10 Feb 2005 (UTC)) To speak of the numbers themselves rather than their presentation: I notice the chart is sourced to IPCC rad forcing 1994. Probably that was me. But anyway: there is a table in the IPCC TAR so they may as well be updated to 1998. The numbers would be a bit higher now, true. So I recalculated the CO2 % as 31 not 40 (up from 278) though if you use the current 377 ish its 35% ish. But... on balance its probably better to have a consistent set of numbers for 1998 from a reliable source. Also, said source http://www.grida.no/climate/ipcc_tar/wg1/221.htm says that Volume mixing ratios for CO2 are in ppm, for CH4 and N2O in ppb, and for the rest in ppt. which was not quite consistent with the table. I *didn't* update perflouromethane cos I don't know which one that is. The SF6 value changed a lot, if anyone wants to check that.

Perfluormethane seems to be a mis-used term, tetrafluromethane - or CF4 would be better. I note the TAR lists a 1750s value of 40ppt or half the current value. I wonder what the pre-industrial source was? Vsmith 15:05, 12 Feb 2005 (UTC)

Persistent vandalism by Vsmith and WMC

Why do you guys persist in removing important information from the chart? Your changes are unnecessary, inappropriate and unwarranted. Not only that, but the changes do not reflect the IPCC data on this subject. Where are you getting these changes?--JonGwynne 00:55, 17 Feb 2005 (UTC)

We don't need to reproduce the entire TAR, do we? The most significant gases are there. Also we don't need the redundant extra column for those non-preindustrial gases. This has been all discussed at length previously and calling users vandals just because they disagree with your POV is not helpful - tone down the blather and be honest in your edit summaries. You did a lot more than just revert your tables. Hmm... I see you've been back with another not a revert as I write this - looks like a partial revert to me. Vsmith 02:01, 17 Feb 2005 (UTC)

OK - let's work with your tables a bit. Fixed a unit error, remove a redundant column in 2nd table (covered it with comment above table), work to make headings and tables more readable. More to do as there is still some confusing parts (need to separate the really trace gases from those of significance - later. The water vapor paragraph is valid and pertinent. Vsmith 03:17, 17 Feb 2005 (UTC)
If you want to find a reputable source for the Mann quote, be my guest. But the retelling of tales from the "Environmental News Service" by commondreams.org hardly qualifies. If Mann really said these things, there should be a more authoritative record of it. Feel free to look.--JonGwynne 12:43, 17 Feb 2005 (UTC)
(William M. Connolley 11:44, 17 Feb 2005 (UTC)) I would prefer to remove the more minor gases (as I did...). The info is available from the TAR and I can't see the point in putting it all in. The radiative forcing from some of the CFC's is within the error bars of the CO2 (or methane) forcing. Its in the TAR because that wants to be complete. And as Vsmith says, flinging around unwarranted accusations of vandalism isn't going to help you.
I doubt the IPCC gives much thought to what you would "prefer to remove". In an article about greenhouse gasses, what it is relevant is the greenhouse gasses the IPCC took the trouble to list, not that tiny subset you would "prefer" to discuss. --JonGwynne 12:42, 17 Feb 2005 (UTC)
(William M. Connolley 14:02, 17 Feb 2005 (UTC)) It is indeed ironic to find JG, who has done his best to undermine the IPCC conclusions, now citing IPCC as the ultimate source of all info. If this represents a conversion no his part, I would welcome it, but I think he is just using the bits he likes. We are *not* trying to reproduce IPCC here.
Well, at least you're closer to the proper use of the word ironic here. But, you're still missing the point. I have no stake in the IPCC's conclusions either way. In other words, it is nothing to do with what I "like". Just because you judge facts according to whether or not you "like" them, doesn't mean the rest of us do. The point, whether you want to admit it or not, is that if you want to cite IPCC data, you have to be prepared to do it accurately or else you will be corrected. The real irony here is that such a hardcore IPCC propagandist like you who receives their proclamations as though they were delivered by a burning bush would be censoring their data. Despite your feeble excuses for censorship and vandalism, the matter for discussion is greenhouse gasses and, if you're going to list them, you's best do it accurately. Oh yeah, and legibly. The tables are not readable without gridlines. I don't know why and I don't particularly care. But whatever else happens, the lines will stay.--JonGwynne 14:56, 17 Feb 2005 (UTC)

Ah, I see they're up to the old tricks again. For the life if my I can't figure out why they insist on censoring the IPCC's own data. You'd think they would be in favor of a complete and accurate discussion of greenhouse gasses, but I guess not. Evidently accuracy and truthfulness mean nothing to them. Not surprising considering their views aren't based on science but rather on faith.--JonGwynne 23:47, 20 Feb 2005 (UTC)

Thanks to Cortonin for fixing JG's mistake

Thanks to Cortonin for fixing JG's mistake with the %: [12]. % is an odd unit though to relate ppm to - perhaps better just deleted? And why waste space on a table of what-ppm-means, when we can just link the first occurence of ppm? --WMC

Or better yet, why use a notation which is sufficiently obscure that it requires a table just to translate it to the common visitor? Scientific notation is standard and prevalent, and works just as well (if not better) as a concentration notation, since scientific notation allows more clear mental comparisons of the relative concentrations. — Cortonin | Talk 15:23, 21 Feb 2005 (UTC)
If only people would realize that percent is just a shorthand for parts per hundred and not some special unit it would make the ppm notation much more understandable. I agree the explanation section is unneeded - I got rid of part of it a day or so ago. Ppm is quite standard and a switch to sci. notation would still need some units as just a "naked number" by itself conveys limited info. And surely anyone able to grasp scientific notation can understand ppm. -Vsmith 15:48, 21 Feb 2005 (UTC)
It's a fraction by volume. A fraction is hardly naked. Ppm is still used when discussing low concentration polutants (which yes, this happens to be), but is much more rare outside of this limited usage. Scientific notation is by far the dominant notation in science for both very large and very small values. In fact, if you check the recommendations of the National Institute of Standards and Technology located here, you will see that they consider ppm, ppb, and ppt "deprecated" and "not uniform", and that the preferred way of expressing numbers is to use powers of 10 (aka, scientific notation). The recommendations of NIST generally do a good job of expressing clear and unambiguous ways to explain things, and we would be wise to follow them for the sake of the readers. — Cortonin | Talk 16:29, 21 Feb 2005 (UTC)
(William M. Connolley 09:35, 3 Mar 2005 (UTC)) Thanks for the kind advice. But I (and I hope the wiki climate pages) will stick with the IPCC, which follows the standards for climatology, in using ppm/b/t.

"greenhouse effect" due to "greenhouse gases"

The problem comes when you start talking about percentages of the greenhouse effect. Yes, clouds are not a gas, but while the article is about greenhouse gases, the opening paragraph is discussing percentage contributions to the greenhouse effect, and for this, clouds are a significant contributer. So it does not make sense to exclude the contributions of clouds to this effect in a tally process. When CO2 is removed, and the others are kept in, to get the 9% value, clouds are included in the amounts left in. So it doesn't make sense to then turn around and exclude clouds from the water vapor amounts. — Cortonin | Talk 22:39, 8 Apr 2005 (UTC)

(William M. Connolley 09:04, 9 Apr 2005 (UTC)) We've been through all this before: see above.
Yeah, I read the above. The points I just raised were not addressed any better above than you just did now. If you're going to erase it as you just did, then please address those points, because the description in the opening paragraphs is incomplete until we do. — Cortonin | Talk 15:49, 9 Apr 2005 (UTC)

I don't think it's quite right to call it a "cloud-free case", since in the 36%, that's 36% of the greenhouse total, which includes clouds, which is reduced upon the removal of water. So it's more accurate to say "not including clouds" than to say "cloud-free case." — Cortonin | Talk 04:58, 12 Apr 2005 (UTC)

Complete list page

(William M. Connolley 21:31, 20 Apr 2005 (UTC)) On reflection, JG is correct to point out that the wiki page contains links to the gases, which is useful.

So why not merge that page with this one and put the better list in its proper place?--JonGwynne 21:49, 20 Apr 2005 (UTC)
(William M. Connolley 22:00, 20 Apr 2005 (UTC)) Don't push your credit, because you have none. All that was discussed before. You lost. Give it up.
Rest your neck dude. I was just asking a simple and civil question, you didn't have to get all <fill in the blank> about it. And since when is wikipedia a "game" than one "wins" or "loses"? Just because some people think it is, doesn't mean that this is the case.--JonGwynne 22:13, 20 Apr 2005 (UTC)
(William M. Connolley 22:35, 20 Apr 2005 (UTC)) You were thinking about restarting the edit war that you lost before: that is the sense of "lost" I meant.
Dude, maybe you should take a few deep breaths and do some yoga or something. You seem to be looking for confrontation where none exists. Remember, there is no spoon. --JonGwynne 23:04, 20 Apr 2005 (UTC)

Global warming potential

The section on Global warming potential largely duplicates that article, to no obvious purpose. I suggest merging the article into that section. As and when the section gets too big, the article can be recreated, and the section be written as a summary of that larger article, instead of a duplication. Rd232 22:30, 28 July 2005 (UTC)

Sounds good to me, GWP is rather redundant with this section. You might want to place a merge to note on that page for those who may watch it and not this one. Vsmith 22:51, 28 July 2005 (UTC)
I still feel a bit unhappy with this. GWP is a thing in itself. The article has the potential to expand, one day, to include how they are calculated and what use they are. William M. Connolley 10:53:24, 2005-07-29 (UTC).
A potential that can quite adequately be met by recreating the article, as and when the section here gets too big. I really don't see the point of having the same thing in two places just because of what might happen "one day". It's easily reversible as and when, and in the mean time merging is clearly better, IMO, because tidier and less likely to lead to contradiction across articles. Rd232 11:43, 29 July 2005 (UTC)
yes, I understand that, which is why I'm only "unhappy" rather than "defending it to the death"... :-) William M. Connolley 14:36:00, 2005-07-29 (UTC).

There's also Global warming, Climate change, and even Paleoclimatology. I don't know what to do about it or I'd do it but it seems there's a lot of overlap in a lot of places. --kop 05:31, 18 September 2005 (UTC)

Of course there should be overlap as these issues deal with the same topic. But all these terms mean something different. Not each should tell the whole story of global warming, but the term should be well defined as it can be expected from an encyclpedia. For more details it should link to a more general article. I assume Climate change could be the more general term where the main climatological processes should be explained. I regard it as more general than Global warming. The term Climate change could also cover cooling effects etc.. Paleoclimatology should simply define the definition of this science. Global warming potential (GWP) should also be kept seperately as this a term, which will get more and more relevant. Especially as IPCC will change and use GWP instead of radiative forcing as the base "climate currency". Therefore I very much like the idea that somebody also describes the state of the art of calculating GWP and refers to papers for deeper insights. RiM

Archive

/archive_1 Carbon Dioxide - the evil villian that is creating a new industry The information contained in this article seems to be selective. We all know that the use of cars and burning of fossil fuels produced carbon dioxide our most hated green house gas. The question is if carbon dioxide is 1.5 times heavier than air which is a fact as opposed to a theory, how is it rising to the upper atmosphere and keeping heat in ?

Common Mr Gore answer that one, or is this Mr Gore's inconvenient truth. —Preceding unsigned comment added by 124.189.51.232 (talk) 09:26, 15 October 2007 (UTC)

It's good to ask questions. There are answers. (P.S. Check out the phenomenon called weather and the feature of weather called wind.)

That's not quite as ignorant a question as it could be. In the past there have been deaths from people going down into unused wells to work on them, with the death being from the lack of oxygen because of the carbon dioxide that had diffused out of the earth and collected in the well. Just read (somewhere) that simply throwing a couple of buckets of water down the well would stir up the air inside enough to eliminate the problem. Nowadays who among us would even be aware of that potential problem? --Minasbeede 14:10, 15 October 2007 (UTC)

Man made sources

I think this article should include a graph showing the man made sources of green house gases against the natural sources of green house gases.

71.28.213.24 01:26, 26 March 2007 (UTC)

It could, but do not be deceived (and do not deceive others) on this point. The global warming problem is a result of fossil carbon being introduced into the biosphere by man (who mines and burns fossil fuels.) Methane from lakes (and cows) is from existing biosphere carbon. Such methane still matters. In addition the lake methane and (in particular) the cow methane may also be attributed to human activity.

There's a huge contribution to greenhouse gases by the natural decay of plant material. Since that's just biosphere carbon recycling again and again it's not the same as the fossil carbon. (If plants could extract the excess carbon as carbon dioxide from the atmosphere rapidly enough - and if that carbon stayed as plant material - then we'd not have as severe a problem.)

Minasbeede 02:39, 11 April 2007 (UTC)

Percentage increase

What does the percentage increase in the table within the section Increase of greenhouse gases refer to? 85.124.182.40 15:10, 19 August 2005 (UTC)

The 1750 baseline, which isn't given separately (the 1998 level and the change from 1750 are). It might be clearer to have the baseline as well as, or even instead of, the 1750-1998 change. Rd232 18:14, 19 August 2005 (UTC)

Why does the top graph go from right-to-left?

Didn't someone just fix that backward graph somewhere else? --James S. 19:04, 28 December 2005 (UTC)

Why not, the axis is labelled. And the net sink bit comes directly from the red/blue line crossover at abt. 1900. Seems sensible to me, what shenanegans are you referring to in that edit summary? Vsmith 21:29, 28 December 2005 (UTC)
Why are all the other graphs going in the other direction? Is there even a single peer-reviewed scientific journal in the English language which publishes time series graphs from right to left? Dragons flight is certainly capable of producing canonical graphs, and I wonder why the prominently displayed images are the only ones with reversed x-axes.
As for net sink, the system used to be in equilibrium. I'm sure you won't mind if I change that to the corresponding "net source" description of artificial sources. —James S. 00:25, 29 December 2005 (UTC)
The red/blue distinction is between fossil fuel and total change, not natural and artificial. —James S. 00:32, 29 December 2005 (UTC)

Dipole

Someone needs to change the line about dipole moments. The problem is that it should either simply say that they cannot absorb light in the IR region, or get fairly technical to explain why. The solution is to probably reference a page or a stub which goes into why. I will think about writing this, however, if it is to be done, how can the top of the page be changed?

Dipoles goes beyond me - sounds like you should be fixing it! And... go edit your user page Josh! William M. Connolley 17:34, 16 January 2006 (UTC).

Global warming potential (again)

I have come a bit late to the issue of whether GWP should be here or not. I have been trying to improve the GWP page which lead me here. I noticed that the section here was now mainly on lifetimes of GHG so I renamed the section and added a small summary on GWP with a link to that page. I think this now works better. Feel free to disagree though..--NHSavage 21:31, 19 January 2006 (UTC)

I meant to remove all the GWP figures from the section on lifetimes. I have now done this. There is a more complete table of figure on GWP in that article

The MOPPIT Sattilite Images

Do these Sattilite images dipict the difference between the seasons, or the increase over a six month period?

E-Mail me an answer at:

donald_johnston@sympatico.ca

Click Me!

—The preceding unsigned comment was added by 206.172.38.200 (talk) 19:54, 14 February 2006 (UTC).

Role of WV

In a comment to [13], Andrew Lacis wrote some stuff that might be useful here one day, so I'll record it before I forget where I read it:

The first statement of the punching bag quote that the combined effect of terrestrial greenhouse gases is to warm the surface of the Earth by 33 C is basically correct. The second statement that 95% of this warming is produced by water vapor is clearly erroneous. Of the 33 C greenhouse effect, about 10-11 C is due to non-volatile greenhouse gases (i.e., gases that do not precipitate out from the atmosphere for the typical range of atmospheric temperatures). These non-volatile greenhouse gases are CO2, CH4, N2O, ozone, and CFCs. If the Earth's atmosphere were totally devoid of water vapor, these non-volatile GHGs would support a surface temparature 10-11 C warmer than the -18 C equilibrium baseline (which corresponds to no atmospheric greenhouse effect). The rest of the 33 C greenhouse effect is due to feedback effects of water vapor which is a reaction to the radiative forcing due to the non-volatile GHGs and accounts for roughly half of the 33 C greenhouse effect, and clouds which provide roughly 6-7 C. As a crude analogy, the non-volatile greenhouse gases serve as a "skeleton" upon which vater vapor (and cloud) feedbacks can operate. (A horse without a skeleton upon which its muscles can exert their force would be laying sprawled out flat on the ground.) Accordingly, if the non-volatile GHGs (CO2, CH4, N2O, O3, CFCs) were removed from the atmosphere, the atmospheric water vapor and clouds would precipitate from the atmosphere, and the resulting surface temperature would drop to the basline -18 C value. In this over-simplified model, the non-volatile greenhouse gases (CO2, CH4, N2O, O3, CFCs) provide an overall radiative forcing of about 11 C. The volatile component (water vapor and clouds) operate in teh current climate system with an effective multiplicative feedback factor of 3 which multiplies the applied 11 C forcing to generate the total 33 C terrestrial greenhouse effect.
An early discussion of radiative forcing and climate sensitivity is given by Hansen et al. 1984 (Climate sensitivity: Analysis of feedback mechanisms. Geophysical Monograph 29, Maurice Ewing Vol 5, AGU, 130-163). This paper compares the radiative forcings due to doubled CO2 and to a 2% increase in solar irradiance, and provides a quantitative analysis of feedback contributions due to water vapor, cloud, lapse rate, and surface albedo changes. The paper shows that while feedback efficiencies of the different feedback processes can be compared linearly, the feedbacks combine in a non-linear fashion. In the Hansen et al. 1984 paper, the radiative forcing due to doubled CO2 was 1.2-1.3 C, with the overall feedback factor in the 3-4 range to produce a 4 C global equilibrium warming. More recent results (Hansen et al. 2005, Earth's energy imbalance: Confirmation and implications. Science 308, 1431-1435) suggest that the total global feedback effect is in the 2.1-2.3 range giving a 2.7 C global warming for doubled CO2.
Because of overlapping absorption and saturation effects, the greenhouse contributions of individual contributors depend on their atmospheric context. For example, the radiative forcing due to doubled CO2 in the current atmospheric context is about 1.2-1.3 C (with no feedbacks operating). But removal of the current CO2 amount produces a cooling of more than -7 C (with no feedbacks operating). Analytic formulas that describe the amount of radiative forcing due to different concentrations of atmospheric CO2, CH4, N2O, and CFCs can be found in Hansen et al. 1988 (Global climate changes as forecast by GISS three-dimensional model. JGR 93, 9341-9364). Again, the (applied) radiative forcing is provided by changes in the non-volatile GHGs, aerosols, or solar irradiance. Water vapor, clouds, and snow-ice albedo change in response to the applied radiative forcing and account for the overall global feedback factor which acts to magnify the applied forcing to produce the eventual equilibrium change in global surface temperature


70.134.105.203 03:43, 8 June 2006 (UTC)-- This is great! This has cleared up a lot of the global warming issue for me. Any charts for water vapor concentrations for the globe similar to the charts for the other gases? --70.134.105.203 03:43, 8 June 2006 (UTC)


Heteronuclear diatomics

The article points out, correctly, that homonuclear diatomic don't absorb in the IR. It doesn't point out that heteronuclear diatomics such as CO or HCl absorb IR. Should it? I don't think they are very important GHG's. William M. Connolley 16:04, 9 March 2006 (UTC)

The logic flow is: O2 and N2 are major atmospheric components (more than 99% of the total), O2 and N2 are homonuclear diatomics, homonuclear diatomics don't absorb in the infrared, therefore O2 and N2, while by far the most significant of the gases in the atmosphere, have no role in greenhouse gas warming. This is mostly in the form of an explanation for why the most abundant atmospheric gases don't contribute to the greenhouse effect. Were CO and HCl to become more prevalent they'd matter more, but they are more reactive than CO2 so even then they'd disappear faster if they weren't being constantly added to the atmosphere. Minasbeede 03:05, 23 April 2007 (UTC)

Not GA yet

This page was nominated on Wikipedia:Good articles/Nominations, but I have not added it to the list, because although the article is generally very good, the intro needs work - it's extremely confusing to quote lots of percentages and then say you can't really quote percentages anyway. Worldtraveller 00:06, 12 March 2006 (UTC)

percentage of greenhouse effect

The major natural greenhouse gases are water vapor and clouds, which causes about 36-95% of the greenhouse effect on Earth (depending on who you ask); carbon dioxide, which causes between 3.6% and 26% (again, depending on who you ask); and ozone, which causes 0-7% (again, depending on the math)(note that it is not really possible to assert that such-and-such a gas causes a certain percentage of the greenhouse effect, because the influences of the various gases are not additive. The higher ends of the ranges quoted are for the gas alone; the lower end, for the gas counting overlaps).

Obviously this needs help. "Depending on who you ask" is not appropriate for an encyclopedia. How one ascribes the greenhouse affect to various gases (and even whether that question makes sense) is going to depend on how one defines the question. We need to either formulate the range of meanings in way that explains where they are coming from and what they mean to the reader or remove them entirely. Dragons flight 20:47, 2 June 2006 (UTC)

Ah, sorry, I reverted that edit as silly before reading your more thoughtful reply William M. Connolley 21:12, 2 June 2006 (UTC)
Actually, the reverted version still has ranges that are not well explained in the text. We need to think about what the reader wants to know when he asks "How important is X to the greenhouse effect?". Dragons flight 21:21, 2 June 2006 (UTC)
Some of the numbers are sourced on greenhouse effect (which has just suffered another of the periodic additions of the 95% nonsense). Sourcing the numbers properly would be good. Answering your question depends a lot on the context; in terms of real life, people asking that question will tend to mean, "is it true wot these people having been telling me, that WV is a more important GHG than CO2"? in which case they need to find the answer, No. William M. Connolley 21:46, 2 June 2006 (UTC)
"No"? I think the answer needs to be more along the lines of "Yes, but..." myself. Dragons flight 21:59, 2 June 2006 (UTC)
Thats where the context comes in. Scientifically, the answer is yes, if by "important" you mean "causes more of the GHE". But in context, important always elides into in-the-human-context, so the answer is No, but... William M. Connolley 22:13, 2 June 2006 (UTC)


70.134.105.203 03:49, 8 June 2006 (UTC)-- As a layperson the large ranges confuse me more than clarify. Unless something more meaning full can be said, the ranges should probably just be removed from the article. The first question that arises when seeing ranges like that is how any useful climate model could be made. I didn’t see anything in the climate model articles that cleared this up. 70.134.105.203

Ah, then you have misunderstood. The ranges are not a problem for the GCMs at all. The ranges essentially come as *output* from the models, not input William M. Connolley 08:52, 8 June 2006 (UTC)
70.134.105.203This would be an excellent clarification to the article, something like “According to climate models the major natural greenhouse gases are water vapor, which causes about 36-70% … “
I was unable to find these numbers on [Global climate model] , [climate model] so I suppose this is the place for the discussion. As I read the article, greenhouse gases were know to absorb (IR) energy from the sun even before climate models, however climate models demonstrate that the cumulative interplay of the anthropogenic increase in these gases do indeed cause an overall increase in global mean temperature. However, as the ranges demonstrate the climate models don’t provide a certainty on the magnitude of the increase. Have I misunderstood? 70.134.105.203 22:52, 8 June 2006 (UTC)


‘water vapor can not be controlled by humans’ ?

I was under the impression that for every molecule of CO2 produced combusting petroleum products, a molecule of H2O is produced, however that no H2O is produced combusting coal. I was also under the impression that petroleum products accounted for about only 25% of combustion derived CO2 and coal most of the rest, however the chart seems to suggest otherwise. May be the chemical formulas would be helpful to the article.

Does Michael Mann mean to say that water vapor can not significantly be controlled by humans? If so, does not that make the “Thus water vapor acts as a positive feedback (but not a runaway feedback) to the forcing provided by human-released greenhouse gases such as CO2.” discussion insignificant also?

The point you are missing is that excess H2O precipitates rapidly. Co2 doesn't William M. Connolley 17:19, 5 June 2006 (UTC)


‘ misleading to cite the role of water vapor as a greenhouse gas ’ ?

In the section about the role of water vapor, I can read:

"It is extremely misleading, however, when scientists cite the role of water vapor as a greenhouse gas," because it can not be controlled by humans

This statement is itself misleading because it intend to change the definition of Greenhouse gas itself. The definition is given at the top of the article and it seems quite clear and unambiguous.

I am worried that such statement is driven more by a political than a scientific agenda. Maybe that some people are interested to diminish the fact that water vapor is the main greenhouse gas.


Equally, a full paragraph is dedicated to the positive feedback between CO2 and water vapor but the fact that Changes in water vapor may also have indirect effects via cloud formation. is rapidly cited without giving us the consequences of an increase of cloud formation. Nageno 10:54, 19 April 2007 (UTC)

You do indeed seem to be more interested in the politics. There are two things that people might be interested in: how large are various greenhouse gases; and what / which gases are driving recent climate change? For the most people, the second question is more interesting, and citing the large amount of WV in this context *is* indeed misleading, which is why people keep doing it William M. Connolley 11:30, 19 April 2007 (UTC)
Thanks a lot for your reply. I do understand that event if WV represents 2% of the atmosphere and CO2 0,0365% does not mean that the effect of WV on the greenhouse effect is 54 times higher. The article clearly states this fact and we can also find information about it in the Greenhouse effect article. To come back to the citation above, I still think it is misleading and should be removed from the article because the definition of a greenhouse gas does not depend on its human origin.
I would also be glad to find more information about the effect of cloud.
If we were only listening to politic, earth would still be flat. Nageno 22:57, 19 April 2007 (UTC)
I recommned listening to scientists not politicians. As to misleading... I repeat my earlier William M. Connolley 09:38, 20 April 2007 (UTC)
The article starts with this definition: Greenhouse gases are components of the atmosphere that contribute to the Greenhouse effect. Then in the section about water vapor we read "It is extremely misleading, however, when scientists cite the role of water vapor as a greenhouse gas," because it can not be controlled by humans. So either we change the definition at the top of the article or we remove the citation. Nageno 10:50, 24 April 2007 (UTC)

I agree, it does seem to be misleading. Water vapor is barely mentioned outside of this paragraph, while it is a key greenhouse gas.--74.229.48.186 16:20, 22 April 2007 (UTC)

CO2 accumulates. CO2 is in the atmosphere at a temperature far above its boiling (sublimation, actually) point. It accumulates. H2O is, usually, in the atmosphere below its boiling point. There are "relative humidity" tables for H2O but there are no "relative carbonic acid (or whatever they'd be called) tables for CO2 because the CO2 isn't going to precipitate out.

Water vapor isn't ignored. The excess carbon dioxide from the burning fossil fuels alters the makeup of the atmosphere. The H2O vapor from combustion very quickly precipitates out as rain, snow, sleet, etc.

H2O is the major greenhouse gas. The global warming problem is a problem that arises from an increase in the average temperature of the earth because of a man-made greenhouse gas. Without the water vapor the earth doubtless would be much cooler, but the issue is not the average temperature of the earth (to which water vapor makes a substantial contribution), the issue is the change in temperature (from CO2.) Get a bunch of some other greenhouse gas into the atmosphere and that other greenhouse gas will be a major contributor to the problem: no claim is made that CO2 is inherently special. Currently the major problem is identified as the annual increase in CO2 because of the huge amounts of fossil fuels (coal, natural gas, petroleum) burned each year (with the amount burned each year increasing.) It's sort of like a budget. Take a balanced budget (with house payments, taxes, insurance, food etc.) exactly matching income and all is fine. Add a $6/day tobacco habit and the budget goes out of balance. The house payment is much larger than the amount spent on tobacco but the tobacco expenditure is the problem. Minasbeede 03:20, 23 April 2007 (UTC)

Really, this article is about greenhouse gas and not global warming. Greenhouse gas is linked to greenhouse effect (see the definition at the top of the article). So, it would be good to find more explanation about the greenhouse effects due to H2O in its different forms (clouds for example). Nageno 10:50, 24 April 2007 (UTC)


Misleading to cite watervapour as greenhouse gas because it can not be controlled by humans? That statement does not belong here. this is an article about greenhouse gases, perhaps that statement should be in the global warming article, or the article about the man-made global warming effect, but most definitely not here. I'm removing it....I can see no possible argument for it being here. Restepc 03:40, 2 June 2007 (UTC)

Greenhouses

I am intrigued by the assertion that the mechanism for greenhouse gas warming is not the one which warms greenhouses.

My understanding of greenhouses is that the glass lets in visible light from the sun. This is then absorbed inside the greenhouse by the contents, which warm up. The contents then emit infra red light - but this is not transmitted back through the glass, which is opaque to IR light, trapping the energy inside the greenhouse and keeping it warm. This is analagous to greenhouse gases - visible light goes in, gets absorbed by the surface and re-emited as IR - but some frequencies of IR are not transmitted back out because they are absorbed by the greenhouse gases and radiated in all directions. Stephen B Streater 18:29, 28 June 2006 (UTC)

Read the greenhouse effect page (and the extensive talk page discussion, poss the archives) William M. Connolley 19:10, 28 June 2006 (UTC)
Thanks. I've added a wikilink in to help the next guy. Stephen B Streater 21:37, 28 June 2006 (UTC)

General cleanup

I've made a number of edits to remove redundant bits of text, clean up some grammatical slips and so on.

I've also changed the description of the greenhouse effect at the top of the page to one that is more accurate scientifically, though maybe too intricate for a general audience. Since this article is about GHGs as such and not the greenhouse effect, I'm sort of inclined to remove this bit altogether and just have a pointer to the main GE article. Raymond Arritt 04:34, 13 August 2006 (UTC)

Hi! I had a part in writing this bit. The most significant thing for me was the discovery outlined in the last sentence: The term is something of a misnomer, as this process is not the primary mechanism that warms greenhouses., so I'd be keener to keep this last sentence than the rest which is, as you point out, explained in its own article; a wikilink could suffice here. Stephen B Streater 17:18, 13 August 2006 (UTC)

Units for radiative forcing

Hi, I'm a bit confused by W/m2 as units for radiative forcing - surely there should be a ppm component to this thing as well? Or some such? Clarification is not to be found in radiative forcing, either. Graft 19:13, 24 October 2006 (UTC)

No... the rad forcing is... well, the 1.46 W/m2 for CO2 is for the 87ppm increase over preindustrial. You could perhaps express it as 1.46/87 W/m2/ppm but it wouldn't be that accurate William M. Connolley 19:46, 24 October 2006 (UTC)
Ah. So, there's an observed forcing for the increase that has actually transpired, 1.46 w/m^2 - but is there some theoretical number, here, i.e., the general potential forcing of CO2? Cuz this is how I read that table. To me it says: given equal quantities of CO2 and methane, methane results in far less forcing than CO2 does. But this is probably not what it's saying. It's actually apportioning the amount of observed forcing attributable to various greenhouse gases. Right? So where does one find the former quantities? Graft 19:50, 2 November 2006 (UTC)
1.46 is calculated, not observed. And no, the methane forcing is smaller, but thats in total - per molecule, methane is stronger. Sorry - I though all this was obvious William M. Connolley 20:40, 2 November 2006 (UTC)
Calculated, observed, same difference - my point is, why don't we have a table of per-molecule forcing? Surely this is relevant? As to it being obvious, maybe it should be, but it could clearly be made more so. Graft 16:56, 3 November 2006 (UTC)
To be fair, since the effects are not linear (in fact logarithmic in many cases) and different gases interfere with each other through overlapping absorption bands, it isn't a trivial matter to construct such a table. Really, such a comparison is most sensibly limited to discussing the forcing associated with small changes in gases relative to the modern atmosphere. Dragons flight 23:06, 3 November 2006 (UTC)
The Expert syndrome: Knowing so much that no one else can understand a word you say. Though if there is a good table on the differential impact of various greenhouse gases relative to the modern atmosphere, I'd love to see it. For some reason, climatologists don't seem to think about greenhouse gases in the same way as physicists. Dragons flight 21:07, 2 November 2006 (UTC)

Emissions by Country

The article is quite graph-heavy already, but can anyone find an appropriate place to add this graph (from the Pollution article)?

Historical and projected CO2 emissions by country (1990-2025). Source: Energy Information Administration.
Historical and projected CO2 emissions by country (1990-2025).
Source: Energy Information Administration.

There seems to be very little in this article (or elsewhere on Wikipedia, unless I've missed it) regarding the differing levels of greenhouse gas emissions between countries, or the differences in growth rates. -84.68.87.155 23:42, 27 October 2006 (UTC)

Go to http://www.eia.doe.gov/emeu/iea/carbon.html for a heap of countries and annual rates of emission.

Hey! How come the countries of Australia and New Zealand got lumped together in the plot?
Australia is downwind of New Zealand's sheep. Kd4ttc 21:47, 8 March 2007 (UTC)

Classroom science experiment?

Can the page suggest or link to a classroom science experiment to test the insulating properties of greenhouse gasses? For example, is there a simple test where the rate of cooling of a beaker of hot water can be measured in a standard atmosphere and then in a carbon dioxide enriched atmosphere? —Preceding unsigned comment added by 128.250.6.243 (talk • contribs) 08:21, 5 November 2006

Hmm... How 'bout two bell jars, two beakers of hot water, two thermometers, a source of CO2 and test. Maybe add manometers and a means of equillizing the pressure of the two bell jars as CO2 is added to one and ... then publish your findings and report back here :-)
Vsmith 14:50, 5 November 2006 (UTC)
Given that the infrared optical depth in the atmosphere is is not huge, I fear you'd need a quite high concentration of CO2 to get a measurable effect on laboratory scales (at least with classroom level equipment). Dragons flight 09:42, 6 November 2006 (UTC)
With appropriate simplifying assumptions, can a basic model be posed to predict the rate of cooling in the two scenarios?
Would a visualisation be possible? Perhaps an infrared camera could be used to observe a bar heater through a partitioned tank that has a standard atmosphere on one side and CO2 on the other.

Right, now to find some scientists that can help out! Would any science teacher and their class of budding scientists be interested in testing the hypothesis that CO2 acts as a greenhouse gas?

repeat the original experiment?

Find the reference to the 1890 experiment. They put a glass tube between a light source (I think they used a mirror reflecting sunlight) and then filled the tube with different gases and measured the temperature.

As a science fair project perhaps two plots of earth (maybe 3 foot by 3 foot) could be covered with a foot-thick frame covered with thin plastic (such as used for dry-cleaner bags), well sealed. One frame could simply contain air, the other carbon dioxide. Leave the frames off during the day and then put the frames over the plots. Measure the temperature periodically. On different nights alternate the frames with the air and the CO2. Tabulate the results.

In other words, the frames are transparent top and bottom. The thin plastic will also absorb infrared radiation but if the frames are identical the difference will be due to the difference between air and CO2.

This isn't a full, perfect CO2 global warming experiment but it's something that can help create understanding. —The preceding unsigned comment was added by Minasbeede (talk • contribs) 16:44, 16 March 2007 (UTC).

Greenhouse Gases - human factor

please go away and read Chapter 3 of IPCC TAR and then come back if you still have any questions.--NHSavage 21:59, 7 November 2006 (UTC)

Just so you know water vapor is just that H2O atomized, it is NOT A GAS! It is Humidity in the atmosphere and NOAA measures it as WATER, not a gas!

However, water vapor still remains the number one contributer to the greenhouse effect. http://www.ncdc.noaa.gov/oa/climate/gases.html#wv

Observational Database

A large observational database of many different atmospheric constituents including greenhouse gases from a host of platforms is available. This was created as part of ESA Envisat and NASA Aura validation. It is of general use. Do you think it should be added to the article text? Dlary 03:16, 4 February 2007 (UTC)

CO2 is a greenhouse gas

It is widely understood that carbon dioxide acts as a greenhouse gas. Out of interest, is there a suitable reference to some fundamental report or study? Chrisnumbers2000 05:48, 7 February 2007 (UTC)

The Arrhenius article is pretty good. Raymond Arritt 05:53, 7 February 2007 (UTC)
The only actual experiment I've found proved that CO2 is a greenhouse gas ONLY if atmospheric pressure increases as well. It was conducted in the 1890's I think, but I haven't been able to relocate it in google. If it really is true that no institution has ever repeated this experiment in such a long time, that makes me... somewhat disappointed in modern science if we can have such a large debate over global warming and CO2 and then nobody has ever ponied up an actual experiment as proof in over a 100 years. How has global atmospheric pressure changed in the past 100 years? Has it increased? Decreased? Stayed the same? 64.126.164.3 04:14, 14 February 2007 (UTC)
Your premise is mistaken. Perhaps you're confusing the partial pressure of CO2 with total atmospheric pressure. Raymond Arritt 04:42, 14 February 2007 (UTC)
I dont remember the specifics because I'm unable to reproduce the search term that brought me to the page with the experiment mentioned. Basically what I remember is that you could have x amount of CO2, and it's ability to be a green house gas increased with y, where y is the total gas stuffed into a container.64.126.164.3 23:43, 14 February 2007 (UTC)

Contrarian references

Please, gentlemen, acknowledge that this is a controversial topic, with well-respected climatologists having very different opinions. Please do not make it an editorial for one POV by deleting references to minority viewpoints. NCdave 17:45, 15 March 2007 (UTC)

BTW, contrarians are by no means nuts. They include some prominent scientists, such as Alabama State Climatologist John Christy, Oregon State Climatologist George Taylor, Colorado State Climatologist William Gray, and many others. NCdave 18:31, 15 March 2007 (UTC)

Fossil Fuel Burning cannot exceed Total Flux, All Sources

This is shown in the top diagram part 2 Carbon Flux. Can somebody fix this? --Nick Green 03:38, 18 March 2007 (UTC)

The lines are correct, but it would be clearer if the legend were labeled as "all sources and sinks". I'll ping Robert and see if he can fix it. Raymond Arritt 03:48, 18 March 2007 (UTC)

Thanks Raymond. Is there any good empirical data on sinks yet?--Nick Green 03:02, 19 March 2007 (UTC)

The TAR chapter is as good a starting point as any though it's a little old by now. The whole carbon sink/sequestration/storage area is moving very fast, both in terms of observations as well as proposals for methods to increase carbon uptake. Raymond Arritt 03:16, 19 March 2007 (UTC)

Thanks again Raymond. Yes the Branson prize might help but we really need to use a mass produced instrumentation approach- we know so little about microbial biomass, for example, and its products- an eGaia Project? Still this is not the place to speculate--Nick Green 14:42, 23 March 2007 (UTC)

New additions to the "Increase of greenhouse gasses" section

This was recently added to the section without any discussion or explanation: Another theory on the cause of CO2 level increases, among other green house gases, is that their increase lags global warming. CO2 levels increase as the global temperature increases. This is partly due to ocean warming. When the ocean warms, it releases CO2. When the ocean cools, it absorbs CO2. When looking at ice core samples from a much broader perspective, we see that CO2 levels increased after the earth began to warm up. Also, in Bruno Wiskel's book "The Emperor's New Climate" (2006), on page 110-112, we see more factors on the release of CO2, among other greenhouse gases, into the atmosphere. Wetlands for instance are the largest producers of methane. As the wetlands warm up, along with the global temperature, their ability to produce methane increases. Some other factors mentioned in Wiskel's book are the release of CO2 from the soil under glaciers, when they melt. As a result, the theory that industrialization has caused global warming could be entirely false.

First, Bruno Wiskel doesn't have an article and the book isn't that well known. A search on Google for "Bruno Wiskel The Emperor's New Climate" returns 11 hits. This section seems very dubious. I'm not saying it is false, but I've never heard anything like this and the person and book cited don't seem that notable. Unless more appropriate citations can be added, I think this section needs to be removed. Ungovernable ForcePoll: Which religious text should I read? 05:23, 7 May 2007 (UTC)

I've removed the new section. Since there is zero scientific support for this new idea (at least for the present day) I don't think it belongs William M. Connolley 10:32, 7 May 2007 (UTC)
I don't blame you one bit. Ungovernable ForcePoll: Which religious text should I read? 10:38, 7 May 2007 (UTC)

The role of water vapor

Why does "The role of water vapor" section keep getting removed by various people? It's very annoying to have to revert edit after edit. Maybe we need to discuss why you don't believe the fact that water vapor is a greenhouse gas.Invasion10 08:56, 17 May 2007 (UTC)

Yes, water vapor is a greenhouse gas

It is necessary to understand the situation and the discussion. When man-made global warming is discussed the topic is, specifically, a change in the average temperature of the earth brought about by the actions of man. That's a change in temperature from what the temperature would be absent the additional greenhouse gas.

Water vapor is the most significant greenhouse gas but water vapor rapidly leaves the atmosphere (snow, rain, hail.) Add a million tons of water vapor to the atmosphere and there very quickly will be a million tons of additional precipitation. Add a million tons of CO2 to the atmosphere and that CO2 will persist for decades, slowly being removed by natural processes. (This isn't a quantitative statement: I don't claim that combustion of fossil fuels, in total, produces equal masses of H2O and CO2. "Million tons" is a phrase used to indicate "a lot.")

Something that also gets too little attention is that a one degree (Celsius) increase in the average temperature of the earth is only a little more than a 0.3% change in temperature. That one degree change can have significant global effects but it's still just a little more than a 0.3% change. It is entirely possible that man's activities can cause a change of that magnitude.

It is false logic to conclude that since water vapor is the most significant greenhouse gas that the effect of added CO2 can be ignored. The global warming issue is not the temperature, it's the change in temperature. The effect of the water vapor appears in the temperature. The added CO2 contributes to an increase in temperature.

Minasbeede 16:30, 18 May 2007 (UTC)

(I removed my intemperate statements about content in article that appeared to be neither factual nor NPOV in nature. What I wrote was also not NPOV.)

Minasbeede 15:27, 1 June 2007 (UTC)

This was added by anon 217.42.21.7 and is now deleted. It's totally wrong, of course, but that doesn't stop it being used as a common skeptic talking point. (Tim Ball even claims that water vapor is left out of the models... sigh.) Raymond Arritt 14:42, 1 June 2007 (UTC)
Would you have a quote for that? We then could address the point head on in the article. — Sebastian 14:45, 1 June 2007 (UTC)
The recent Soden and Held (2006) article diagnoses cloud feedbacks in GCMs (it would be tough to diagnose something that doesn't exist). There's a nice figure that shows magnitudes of the various feedbacks. Or were you thinking of a quote from one of the IPCC reports or another source that says something very direct, along the lines of "All modern general circulation models contain parameterizations for radiative transfer, clouds..."? Raymond Arritt 15:06, 1 June 2007 (UTC)
It doesn't have to be all; the claim that "cloud formation [is] largely ignored in climate models" is easily refuted by a statement like "modern general circulation models, such as ..., model cloud formation". Would you have a link or two that we could use as a reference? — Sebastian 18:25, 1 June 2007 (UTC)
Maybe something like this excerpt from chapter 8 of the WGI report of the AR4: "Cloud parametrizations are based on physical theories that aim to describe the statistics of the cloud field (e.g., the fractional cloudiness or the area-averaged precipitation rate) without describing the individual cloud elements. In an increasing number of climate models, microphysical parametrizations that represent such processes as cloud particle and raindrop formation are used to predict the distributions of liquid and ice clouds. These parametrizations improve the simulation of the present climate, and affect climate sensitivity (Iacobellis et al., 2003)." (reference here; specifically at subsection 8.2.1.3.) I'd still like to find something that explicitly says "all modern GCMs include the effects of clouds", but it's such an obvious point that maybe no one has bothered stating it. Raymond Arritt 19:06, 1 June 2007 (UTC)
(addendum) Maybe "current state-of-the-art climate models include fully interactive clouds" from this source? Raymond Arritt 19:12, 1 June 2007 (UTC)
That's perfect! I'll add that. — Sebastian 22:13, 1 June 2007 (UTC)nooooooooooooooooooooo
Actually, that belongs rather in the article Climate model. I'll write something on its talk page, please follow the discussion there. — Sebastian 22:22, 1 June 2007 (UTC)

Logarithmic relationship between CO2 levels and absorption.

No discussion on greenhouse gas, CO2, water vapor, or otherwise, can be considered accurate or complete without an explanation of Beer's Law as it applies to the absorption of radiation by these gasses. It is not a direct relationship such as "the more gas, the more absorption." It's logarithmic. Each additional increase has less and less effect until you reach saturation. CO2 is already nearing that saturation point, and therefore more of it in the atmoshphere has little effect. You would have to add roughly 10 times as much as current levels over the next 100 years to have the same effect as the last 100, and this is total CO2, not just human emissions. Additionally, the arguement that water vapor "doesn't count" becasue of its short lifespan in the atmosphere is bunk as this only applies to the lifespan of a particular molecule of water vapor. The water cycle is continuous, therefore the overall levels of water vapor, for all intents and purposes, remain the same. As one molecule condenses back into liquid water, another is evaporating and entering the atmosphere. [this unsigned comment was added on 23 May 2007 by 63.237.28.10]
(Don't forget to sign.)

In other words, adding more CO2 to the atmosphere is much like adding another layer of paint to an already almost-opaque surface. It doesn't reduce the amount of transmitted light by very much at the wavelengths that it blocks, because those wavelengths are already mostly blocked anyhow.
The second illustration in the article ("Radiation Transmitted by the Atmosphere") illustrates 63.237.28.10's point pretty well, if you study it: most of the wavelengths blocked by CO2 are already almost 100% blocked.
You are right, 63.237.28.10. This article definitely needs a discussion of Beer's Law. NCdave (talk) 01:52, 16 March 2008 (UTC)
The paint analogy is not useful, for many reasons (not the least of which is that it concerns visible wavelengths rather than thermal IR). The bit about saturation of wavelength bands is a widely-held misconception; see Spencer Weart's review for an excellent educated-layman level discussion.[14] The key sentence there is "The greenhouse effect will in fact operate even if the absorption of radiation were totally saturated in the lower atmosphere." Please read the rest of Weart's article for the full explanation. Raymond Arritt (talk) 02:39, 16 March 2008 (UTC)
Thank you for the interesting link, Raymond. The author is arguing that it matters not only how much of the radiation is absorbed, but at what altitude it is absorbed. He contends that it is the upper atmosphere which matters the most:
"The greenhouse effect will in fact operate even if the absorption of radiation were totally saturated in the lower atmosphere. The planet's temperature is regulated by the thin upper layers where radiation does escape easily into space. Adding more greenhouse gas there will change the balance..."
But that is not describing the greenhouse effect! The greenhouse effect is the blockage of IR radiation from the surface of the earth. The more thoroughly that radiation is blocked in the lower atmosphere, the less of it reaches the upper atmosphere. NCdave (talk) 07:25, 19 March 2008 (UTC)
No, the greenhouse effect is derived from the total ability of the atmosphere to capture and recycle thermal radiation. It is not just the Earth's surface that emits IR. The atmosphere also emits thermal radiation. IR from the lower atmosphere can be captured by greenhouse gases in the upper atmosphere, etc. High levels of greenhouse gases in the lower atmosphere capture IR radiation from the surface and warm the lower atmosphere. In turn the warmed lower atmosphere will emit more IR. Depending on circumstances, this can even lead to more IR radiation reaching the upper atmosphere than if no greenhouse gases were present at all. The logarithmic relationship is largely a consequence of the fact that the atmosphere is not only an absorber but also an emitter of infrared radiation. Dragons flight (talk) 07:48, 19 March 2008 (UTC)
Only if atmospheric GHGs emit more energy than they absorb could increased levels of GHGs in the lower atmosphere actually increase the amount of energy absorbed in the upper atmosphere from below. Since GHGs are not significantly radioactive, that doesn't happen.
The logarithmic relationship is simply due to the additive effect of filtering. If X ppm of a particular GHG passes 50% (and blocks 50%) of a particular wavelength, then 2X ppm will pass 25% (i.e., it blocks an add'l 25%), 3X ppm will pass 12.5% (i.e., it blocks an add'l 12.5%), 4X ppm blocks an add'l 6.25%, 5X blocks an add'l 3.125%, etc.. In other words, each addition of X ppm blocks less and less of the wavelength in question than did the previous addition of X ppm, and thus has less effect on temperature than did the previous addition of X ppm. NCdave (talk) 09:15, 19 March 2008 (UTC)
Blankets increase your warmth without needing to generate heat. It is the same with GHGs, more of them leads to an accumulation on energy near the surface. This energy is ultimately derived from the sun but the equilibrium state of everything shifts to higher temperatures as energy is trapped near the surface, leading to higher fluxes as I describe.
Your scale is not logarithmic. A logarithmic scale implies that if doubling CO2 causes k degrees warming than four times CO2 causes 2*k warming, and eight times CO2 causes 3*k warming. According to your logic, 50% of the warming would occur with X ppm and only twice that would occur at infinite concentration. The primary band for CO2 already absorbs 100% of radiation. The logarithmic sequence arises from consideration of the altitude at which radiation in that band can travel before being fully absorbed, in other words the key feature is the optical depth. Dragons flight (talk) 10:19, 19 March 2008 (UTC)
Dragon, the logarithmic relation is w/r/t amt of IR radiation escaping, compared the amt emitted at the surface:
Eescaped = Eemitted / 2**k
Eemitted / Eescaped = 2**k
log2(Eemitted / Eescaped) = k
Make sense? Of course, the key point is the observation that each addition of an amount k of GHG captures/blocks less IR than the previous addition of amount k, just as the 10th blanket on your bed increases your warmth by less than the 1st. If your goal is warmth, then additional GHG or additional blankets have diminishing returns. NCdave (talk) 15:48, 25 March 2008 (UTC)

Possibly the above discussion is more suited to the greenhouse effect article, or the global warming article, than here... Restepc (talk) 10:35, 19 March 2008 (UTC)

A Response

It's one thing to claim that CO2 is nearing the saturation point and another thing to show it. You've claimed it but have shown no reference to back the claim. Show the data, please, if it exists. Surely the absorption coefficients of CO2 are well enough known that this should be a simple matter.

It's rather unlikely that of all the scientists who warn of the greenhouse gas crisis none are aware of Beer's law. In particular those scientists who do modeling of the effect of an increase in atmospheric CO2 are overwhelmingly likely to do the computations according to Beer's law and not according to a linear mode. Still, over any small range, doesn't a logarithmic curve look approximately linear?

Your explanation of the reason water vapor is not considered a greenhouse gas of concern is far better than one that talks of a short lifespan, although these are or should be different ways of expressing the same thing. the "short lifespan" statement about water vapor implies a comparison with CO2, which has a longer lifespan since there is no mechanism similar to precipitation that quickly removes CO2 from the atmosphere. There, again, it isn't individual molecules that matter (and molecules of water are indistinguishable one from another), it's the total concentration. Burning of fossil fuels is another source of atmospheric CO2. Absent the burning of the fossil fuels there would be more or less of a balance among atmospheric carbon (as CO2), biological carbon, and carbon in dissolved CO2 in the oceans and lakes. The CO2 concentration measurements taken in Hawaii would show the same seasonal variations but would lack the constant upward motion attributed to the increase in atmospheric CO2 from burning fossil fuels.

Minasbeede 03:41, 24 May 2007 (UTC)

FOUR MAJOR QUESTIONS 1)As the temperature of the Atmosphere increases do the oceans absorb some of the heat; water is a very good heat sink, and doesn’t the increasing ocean temperature cause increased evaporation and reduce the oceans ability to trap CO2? 2)How exactly do 308 molecules out of 1,000,000 get warm enough to heat the total number of molecules, there doesn’t seem to be enough mass. Say that CO2 was 1,000 times hotter than the other gasses do to i ts “greenhouse-ness” there would be no thermometer detectable increase in the total temp… maybe a thousandth of a degree? 3)And aren’t the Oceans a huge, HUGE (huge is not adequate to describe the relative size of the Oceans vis-à-vis the Atmosphere) , heat sink removing heat from the atmosphere? 4)So exactly how are the additional 100 parts-per-million of CO2 molecules over 100 years going to increase the temperature of the Earth? Might not the Sun be the cause of the global warming? Might the warming be the cause of the additional CO2 as follows; Warming surface of the Earth releases CO2 from the soil, warming oceans release CO2 from their stores? mefcrf:Mefcrf 07:53, 2 June 2007 (UTC)

A1: Increased water vapor and lessened ability to trap CO2 are both positive feedback mechanisms for warming. With global warming everything can get warmer, including the oceans.

A2: The issue is energy. Absent the extra CO2 more of the daily amount of solar energy absorbed by the earth would escape directly to outer space. If more energy is absorbed in the atmosphere the net result is a slowing of the escape of that daily dose. All the energy that the earth absorbs from the sun eventually re-radiates. Most re-radiates the same day. Some of the energy absorbed by the atmospheric CO2 will re-radiate at the same frequency as the radiation that was absorbed, some will get transferred to other molecules by collisions. The details may be complex. The essential consideration is that energy is conserved. If the energy doesn't make it to outer space in a single step then its escape to outer space is slowed, by definition.

A3: Same as above. If the oceans absorb energy they get warmer. That, too, is part of global warming.

A4: By slowing the escape of solar energy to outer space. Most of the solar energy absorbed each day is radiated into outer space as infrared radiation. The added CO2 in the atmosphere causes a small part of the radiation from the surface to be absorbed in the atmosphere. (Consider other infrared radiation for which there is no atmospheric absorption. It escapes earth in a single shot.) The sun is what makes the earth habitable. The sun is the reason the earth isn't at 4o Kelvin. If the sun puts out more energy per unit time the earth will be warmed by that. No credible spokesperson claims that the earth's temperature has always been constant and would remain so absent global warming. Added release of CO2 due to warming is a positive feedback mechanism. Dead plant material rots. IF it's warmer the rotting process is likely to be faster, causing the amount of CO2 returning to the atmosphere to go up: positive feedback.

A 1° change in the average temperature of the earth is under a 0.4% change in the average temperature of the earth. While that is a small change it has major effects. Those major effects are the reason for the concern. Absent the major effects global warming would be "no big deal."

Minasbeede 15:25, 2 June 2007 (UTC)

One More Time: Exactly how does a 100 parts per million over 100 years cause the kind of warming observed? What model shows this? 68.101.111.61 07:41, 3 June 2007 (UTC)mefcrf

You've been given he answer, even if you haven't understood it. The answer is basic radiative physics plus some feedbacks, or perhaps HadCM3 William M. Connolley 09:22, 3 June 2007 (UTC)

Please see radiative forcing. James S. 15:11, 5 June 2007 (UTC)

Emissions

I see no claim made that all emissions due to burning of fossil fuel remain entirely in the atmosphere. Either the vehicular emissions did or did not grow as was claimed in the removed material. The level of emissions of greenhouse gases from the combustion of fossil fuel is pertinent, is it not? That the growth in atmospheric CO2 is less than the total emissions over a period of time does not disprove the level of emissions nor reveal the data to be incorrect.

Minasbeede 14:09, 5 June 2007 (UTC)


source of graph

What is the source of the graph "green house gas emissions by source"? Northern Bear 16:36, 5 June 2007 (UTC)

According to [15]:

This figure shows the relative fraction of man-made greenhouse gases coming from each of eight categories of sources, as estimated by the Emission Database for Global Atmospheric Research version 3.2, fast track 2000 project. These values are intended to provide a snapshot of global annual greenhouse gas emissions in the year 2000.

--Kim D. Petersen 17:18, 5 June 2007 (UTC)

Repeated deletions of National Academy of Sciences findings

William M. Connolley has repeatedly[16][17][18] deleted the following section, sourced to a peer-reviewed National Academies of Sciences report:

Underestimation by IPCC 
The Intergovernmental Panel on Climate Change (IPCC) underestimated 2000-04 CO2 emissions by a substantial amount. CO2 emissions from cars, factories, and power plants grew at an annual rate of 1.1% during the 1990s, but from 2000 to 2004, CO2 emissions growth rates almost tripled to 3% per year.[1]
  1. ^ Raupach, M.R. et al. (2007) "Global and regional drivers of accelerating CO2 emissions" Proceedings of the National Academy of Sciences

The reasons given in summaries were:

  • "rv: as per GW page: releveance is dubious AND atmos CO2 only grew at 2-3/y ppmv in 2000-4"
  • "rm - remains of no clear importance - needs to discuss short timeframe & actual CO2 concs)"
  • "its not criticism; other reasons as before"

The abstract of the source reads:

"CO2 emissions from fossil-fuel burning and industrial processes have been accelerating at a global scale, with their growth rate increasing from 1.1% y�1 for 1990–1999 to >3% y�1 for 2000– 2004. The emissions growth rate since 2000 was greater than for the most fossil-fuel intensive of the Intergovernmental Panel on Climate Change emissions scenarios developed in the late 1990s. Global emissions growth since 2000 was driven by a cessation or reversal of earlier declining trends in the energy intensity of gross domestic product (GDP) (energy/GDP) and the carbon intensity of energy (emissions/energy), coupled with continuing increases in population and per-capita GDP. Nearly constant or slightly increasing trends in the carbon intensity of energy have been recently observed in both developed and developing regions. No region is decarbonizing its energy supply. The growth rate in emissions is strongest in rapidly developing economies, particularly China. Together, the developing and least-developed economies (forming 80% of the world’s population) accounted for 73% of global emissions growth in 2004 but only 41% of global emissions and only 23% of global cumulative emissions since the mid-18th century. The results have implications for global equity." (emphasis added)

Since this is clearly criticism, I believe that WP:NPOV requires the inclusion of this caveat. I would like to know what other people think. --James S. → talk 07:50, 8 June 2007 (UTC)

First, no it isn't criticism. Its just some findings. Second, your reporting of it is badly biased because you are failing to report on the all-important atmospheric concentrations which actually remain within SRES bounds. Which you know because it was discussed on t:GW William M. Connolley 08:54, 8 June 2007 (UTC)
"Findings" that observations are not in line with IPCC projections are most certainly criticism -- what reason do you have to say that they are not? Even if they weren't, they would still be a different, important, and impeccably sourced point of view, and must be included. Atmospheric concentrations aren't the subject of the report, emissions are. Why are concentrations "all-important"? They may be within SRES predictions at the moment, but if emissions continue to rise as much as have been above IPCC predictions, they will not be for long. --James S. → talk 12:45, 8 June 2007 (UTC)
This is hopeless. Why are concs all-important? For the obvious reason: they provide the radiative forcing. Emissions don't. And you still persist with your own bizarre defns; this is not crit. Now, if you want to add something balanced and sensible in the CO2 emissions section, that would be fine William M. Connolley 12:51, 8 June 2007 (UTC)
The CO2 emissions section is under external links, but I added the PNAS and Science quotes anyway. --James S. → talk 05:06, 11 June 2007 (UTC)
What provides the concentrations? The emissions! I'm looking at a half dozen definitions of the word "criticism" and I can't believe you when you say the Raupach paper isn't a "comment expressing fault" or a "critical comment or judgment" or a "serious examination and judgment of something" -- why you would think that it's not all three of those is unclear to me. --James S. → talk 13:11, 8 June 2007 (UTC)
Concs are measured in the atmos. Its clear that they are pretty well on the IPCC proj's - not way above William M. Connolley 13:29, 8 June 2007 (UTC)

Its clear to me that James and I strongly disagree on this. Based on past experience, I doubt we will come to any understanding so I invite others to express their opinions William M. Connolley 13:29, 8 June 2007 (UTC)

I've mv'd and re-written it into what looks like the most appropriate section William M. Connolley 20:41, 11 June 2007 (UTC)
I'm collecting all the findings of the PNAS paper and will add a balanced representation of them shortly. Bendž|Ť 11:53, 16 June 2007 (UTC)
Alright, I've read the discussion on the global warming page, and Connolley, you're violating WP:OR by giving precedence to your own reading of the graph data over the author's interpretations in text of the research paper. I did notice the discrepancy but let's just report what the scientists find, shall we? All sorts of adjustments have to be made to be able to use data from different sources, but if they conclude one thing from the data it's not our place to say that's incorrect when it has been peer reviewed by the United States National Academy of Sciences. Until another paper points out an error, we'll have to settle for the findings in this one. Bendž|Ť 13:46, 16 June 2007 (UTC)

Water vapour

Is the latest deletion another example of censorship on Wiki? Water vapour does indeed condense when air rises and forms clouds. Clouds reflect sunlight and thus cool the earth. In addition, rain fallng from clouds dissolves CO2 very readily, so s another example of negative feedback. Are you questioning the basic science of my additions? It may not be mentioned in your paper (which I find hard to believe), but surely must be added to the current article, which in its current form is highly misleading. Peterlewis 16:54, 11 July 2007 (UTC)

You can check yourself if its in the paper - here is the full version[19] --Kim D. Petersen 18:11, 11 July 2007 (UTC)
The wikitext (and I assume the paper, but I haven't checked) says that relative humidity stays approximately constant. If that's true then the cloud frequency shouldn't change much, which would mean that the negative feedback you suggest isn't occuring even though there is more total water content. Dragons flight 18:32, 11 July 2007 (UTC)
Precisely; cloud frequency doesn't increase from this, which means no increase in albedo (so no cooling there). We're looking at water vapor as a greenhouse gas, not aerosols, not clouds. Maybe it will rain more in a warmer world, but you'll have to back that up. Bendž|Ť 19:15, 11 July 2007 (UTC)
So increased water vapour content doesn't lead to cloud formation? In the real world (as opposed to the model world) this is what happens as you increase water content in the air. As humid air rises it condenses, or don't the models allow for this obvious fact? Most models appear to predct greater ran , which will wash more CO2 from the air. Simple physics. Peterlewis 20:15, 11 July 2007 (UTC)
It takes more water to make a cloud when the air is hotter. The statement about relative humidity is suggesting that the two effects about cancel out. In other words, the increased difficulty in forming clouds due to higher temperatures is about balanced by the fact that there is more water vapor in the air. And yes, the models do cover this. Also, I think you'll find that appeals to "simple physics" won't get you very far in climate discussions where there are many different issues to consider. References to research findings are much better. Dragons flight 20:26, 11 July 2007 (UTC)
It may well be that "more CO2" is washed from the air (simple physics) but the measurements show that the atmospheric CO2 level is increasing. The measurements indicate that approximately half the CO2 released by the combustion of fossil fuels doesn't stay in the atmosphere. Maybe some that doesn't stay is washed out of the atmosphere by rain, including the postulated extra rain. The warming effect is from the roughly half that isn't washed out or otherwise removed.
If there are more clouds and they're going to be used to argue against global warming due to fossil fuel combustion then it would seem necessary to discuss both the daytime and the nighttime effects of clouds. Day and night clouds have a greenhouse effect. During the day they reflect some sunlight (reducing the solar energy reaching the earth) but that's not the sole effect of clouds. Is there a model study anywhere that indicates what the temperature of the earth (or an earth-like planet) would be if it were 100% covered with clouds 100% of the time? Warmer than the actual earth, or cooler? (I can't even guess whether a permanent light cloud cover or a permanent heavy cloud cover would lead to the greatest warming - or greatest cooling.) Minasbeede 21:10, 11 July 2007 (UTC)

You guys are all missing the point that greenhouse gasses increase the temperature BELOW them, not ABOVE them. You can have a higher temperature and higher WV content in the lower atmosphere, but the temperature in the upper atmosphere is not increased to as great a degree, so it does stand to reason that there will be greater frequency of clouds with a warmer lower ATM and a relatively cooler upper ATM. With greater temperature variation in the z-axis, get ready for some good thunderstorms, folks.

Oh, come on. Greenhouse gases migrate throughout the atmosphere. The greenhouse effect is not as simple as a sample in an IR cell absorbing IR radiation. If CO2 at altitude X absorbs some energy (as IR radiation at a frequency that CO2 absorbs) then all that energy gets re-radiated, some of it at that same frequency. (Maybe there's a valid quibble about "all" being re-radiated. Energy is conserved and the models have to incorporate that fact. I'm not a model expert: such an expert could give you actual detail about the models used.) Some radiates up, some radiates down. There is CO2 up and CO2 down: absorption can happen up and down. There is no magic boundary that lies between "lower atmosphere" and "upper atmosphere." If the models don't include that the energy gets re-radiated then they are indeed useless. What is far more likely is that the models do take into account the conservation of energy and do model energy transferring out of each cell in the model just as much as the model energy transferring into each cell - and do so realistically. --Minasbeede (talk) 03:08, 18 April 2008 (UTC)

Most models suggest that a permanent cloud deck causes a chilling effect at the surface because the heat at the Earth's surface comes from the Sun (at least, it is orders of magnitude greater than the heat that seeps from below the crust). —Preceding unsigned comment added by 68.80.43.122 (talk) 17:01, 14 February 2008 (UTC)

That claim about "most models" is entirely unsubstantiated and it is also so incomplete as to be laughable. Clouds are known to keep the earth warmer. At night. How often is frost or dew seen in the morning after a cloudy night? Clouds form when the temperature drops below the dew point. When do temperatures most frequently drop? At night.

I think, too, that it is believed that Venus is warmer than it would otherwise be because of its permanent cloud cover.

I don't edit any of the articles anymore because I do not consider myself competent enough in the science to do so. I can comment here. --Minasbeede (talk) 03:08, 18 April 2008 (UTC)

Logarithmic

Re [20]: FWIW the effect *is* logarithmic: but this (of course) doesn't make additions negligible William M. Connolley 21:05, 31 August 2007 (UTC)

Logarithmic behavior has been mentioned several times above already. I think if the "logarithmic behavior" argument is to be used it has to be used in the context of a complete analysis or model and not merely invoked without exposition. I'm not a climate professional so I won't attempt to deal with this issue but I can see how what is claimed or implied by those who bring up "logarithmic behavior" is different from reality. Minasbeede 21:18, 31 August 2007 (UTC)

Agreed. logarithmic => negligible is one of the stupider septic arguments around. But explaining the dependence would be sensible William M. Connolley 21:38, 31 August 2007 (UTC)

It probably would, but I suspect that the way to do it is within the context of a model, and that alone would take a lot of explaining. What I suspect is that the flaw in the logic is the implicit assumption that the radiation either makes a single pass through the atmosphere or is stopped by a greenhouse gas just once. Can't be so. The energy eventually makes its way to outer space (or we'd all be really hot.) As the greenhouse gas levels increase it would take more hops, on the average, for the blocked component of the radiation to escape, with that causing global warming. But I'm not an atmospheric scientist, I can't provide a reference to any work that describes it, so I won't put it into the article. (I've left out repartitioning of the energy within the atmosphere that would have to occur. That's why I think a model is needed.)

To me global warming is the result in an increase in the average time it takes for solar energy received as solar radiation to escape the earth into outer space. That, too, I have no reference for. The point here is that while global warming can be represented as a very slowly increasing "average temperature" it's really something that happens every day. Which is sort of a "duh" statement, because the greenhouse gases that are the source of the man-made warming are in the entire atmosphere (pretty much, close enough) and have an effect 24/7.Minasbeede 22:22, 31 August 2007 (UTC)

I would suggest that the best article for discussing the logarithmic effects would be the Radiative forcing article. Ben Hocking (talk|contribs) 22:39, 31 August 2007 (UTC)

Origin of Gases

All greenhouse gases occur naturally except for chlorofluorocarbons, so the article should state the truth and not a half-truth. We should not kid the readers.Peterlewis 21:38, 5 September 2007 (UTC)

So we could say "All greenhouse gases occur naturally except for chlorofluorohydrocarbons" - no, that would be misleading William M. Connolley 22:01, 5 September 2007 (UTC)
I see that sentence as just being introductory: some greenhouse gases occur naturally, some are man-made. I don't see any quantitative indication in the sentence nor any need for such an indication. The sentence sets the stage: there are naturally occurring greenhouse gases, there are man-made greenhouse gases. The article then goes on. The greenhouse gas effect has been understood for about 100 years (even if 100 years ago the means for doing quantitative of effects were inferior to those today.) The sentence could be paired negatives: not all greenhouse gases are natural & not all greenhouse gases are man-made. That's cumbersome, and doesn't say any more than saying some occur naturally and some are man-made. --Minasbeede 00:13, 6 September 2007 (UTC)
The sentence implies a false dichotomy: are CO2, CH4, and N2O natural, or are they man-made? The answer of course is "yes", but as written the sentence obscures that. Raymond Arritt 00:19, 6 September 2007 (UTC)
"Yes" they are both - I can't even figure out your point. The sentence does not identify any greenhouse gas and isn't meant, as far as I can tell, to do anything other than to state that greenhouse gases arise both from natural causes and from human activity. Looked at from a WP perspective, it's fully NPOV (it hardly says anything.) It's (as far as I can see) not a sentence that in any way attempts to apportion greenhouse gas effect according to the source of greenhouse gases, it's just saying some are natural, some are man-made. If the article itself as a whole fails to spell out the origins of greenhouse gases then that's where editing may be needed. --Minasbeede 00:33, 6 September 2007 (UTC)


I'm gonna have a stab at changing it, it certainly can't stay as it is, it's extremely misleading. If you want to change what I've written, do so, hopefully eventually we can get something good...but, do not simply change it back to what it is now, it is currently misleading and that can in no way be preferable to whatever I'm about to write. Restepc 13:13, 30 September 2007 (UTC)


Okay, so I guess I can't change it, wiki lags out whenever I click 'save page'. This is what I came up with

Greenhouse gases are components of the atmosphere that contribute to the greenhouse effect. With the exception of Chlorofluorocarbons, the main sources of all greenhouse gases are natural, but human activity also contributes to some, and is the sole source of Chlorofluorocarbons. Greenhous gases include water vapor, carbon dioxide, methane, nitrous oxide, and ozone.

constructive criticism/edits are welcome, I'm aware it's not exactly poetry, I'd be grateful if someone else who has a better relationship with the wiki-server can change it for this, or their own version of this. Restepc 13:37, 30 September 2007 (UTC)

It seems that there's a desire to communicate a message that most of the greenhouse gases are natural and to press that message into being support for an attitude that since most of the gases are natural there's not any real reason for concern (a denier message.) Perhaps both Wikipedia and the world as a whole could do a better job of distinguishing between the average temperature of the earth and the influence of greenhouse gases on that and the change that is occurring in the average temperature of the earth due to the added man-made greenhouse gases. To make that distinction is fully reasonable. It is quite true that the naturally occurring greenhouse gases have a bigger effect on the temperature. The concern isn't over the temperature, it's over the increase in temperature, and that increase can be attributed to the added greenhouse gases, principally from the combustion of fossil fuel. That is, it's reasonable unless deniers try to confuse people about the difference between the temperature and the change in temperature (which, of course, is exactly one of the deceptions they attempt.) It's useful clarification to show most of the greenhouse gas effect comes from naturally occurring gases. Following that, it's useful to show that the added greenhouse gases are adequate to cause an increase in average temperature that is reason for concern, attention, and action. Ideally, the educated citizen will know pretty well what the major influences on the average temperature of the earth are. Then the educated citizen can understand what's being discussed. The educated citizen will need to know that while most of the greenhouse gas effect is due to naturally occurring gases in the atmosphere and has been so from far before there were any significant man-made greenhouse gases the added greenhouse gases due to the activities of man do have a large enough effect to be of concern. The educated citizen will also need to know that the accelerated rate at which man-made greenhouse gases are being added to the atmosphere presents a serious threat. Make certain that no change to the article serves to mask the reality. --Minasbeede 17:49, 30 September 2007 (UTC)


What the hell are you talking about?

This is a simple paragraph to say where greenhouse gases come from, what is currently in the article is WRONG and should be changed as soon as possible, for something that important to the subject at hand to be wrong is a major problem. It is clear the paragraph cannot stay in its current state, if you do not like my new version feel free to suggest an alternative....all we are trying to do is say where greenhouse gases come from.

Restepc 05:29, 1 October 2007 (UTC)

Well maybe you should carefully and fully describe just how the current paragraph is "misleading." Apparently it doesn't say or imply something you want it to say or imply. That doesn't equate to "misleading."
The paragraph say the gases are components of the atmosphere. That's true.
The paragraph says the gases contribute to the greenhouse effect. That's true.
The paragraph says some greenhouse gases occur naturally. That's true.
The paragraph says others result from human activity. That's true.
The paragraph gives the example of burning fossil fuels such as coal. That's valid.
The paragraph says greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, and ozone. That's true.
So how is it misleading? How is the article "WRONG"? What are you talking about?--Minasbeede 14:08, 1 October 2007 (UTC)


Saying some gases come from natural sources and some from human activity gives the impression that gases are either natural or human caused, which is higly misleading. I am amazed you could not see that was my point.

That's what needs changing....another slightly smaller problem is I think there should be an entire section on the sources of greenhouse gases, rather than just giving an example in the intro....and if we are going to give an example it should be the biggest source we use, not burning coal......it is frankly amazing that this article barely mentions natural sources, and appears to be intentionally leaving out the fact that the majority of greenhouse gases come from natural sources. Restepc 17:14, 1 October 2007 (UTC)

Read "Role of WV" above. that seems to cover your concern, at least in part.

As I understand it the gases are either natural or human caused. How is that misleading? What false conclusion might a reader reach from reading that? I still see that paragraph as just being introductory. Greenhouse gases serve to make the earth warmer. Some of the GG in the atmosphere are there naturally, some result from human actions. What's wrong with that? --Minasbeede 17:31, 1 October 2007 (UTC)


Amazed you can't see it....do you mind me asking if English is your first language? In nay case you are the only person in this discussion who doesn't see the problem with it, so I'm changing it, if you have a problem with my new version please say what it is and we can discuss it, but it certainly can't stay as it is.


EDIT: Okay I've changed it now, but decided to say 'but human activity also contributes to many' rather than 'human activity also contributes to some' Restepc 20:52, 1 October 2007 (UTC)

As per MB, your new intro was misleading, so Ive reverted it William M. Connolley 21:10, 1 October 2007 (UTC)
Your edit collided with mine that contained a "hint" that someone should revert. I'll take out my wording now, too. It was good the way it was. --Minasbeede 21:19, 1 October 2007 (UTC)


MB, you said in reply to someone making the same argument I am now "there are naturally occurring greenhouse gases, there are man-made greenhouse gases."

This is wrong....there is ONE manmade greenhouse gas...there are not some gases which are natural and some which are manmade....the vast majority come from both natural sources AND human sources. The article in its current form reads to an uneducated reader as if there are some natural gases (eg watervapour) and some human-caused gases (eg CO2).

This is highly misleading at best and a lie at worst, it can not remain as it is.

William, as I've said if anyone has a problem with my new version I'd like to know what it is, and what they would suggest instead. When I am next on a computer which doesn't lag out when I try to edit wiki, I will make another attempt at re-writing it, if you have a problem with that change as well please either tell me what your concerns are so we can work on a version we all agree on, or change it yourself to something else, please do not revert it to the old misleading version. Restepc 22:17, 1 October 2007 (UTC)

You are reading into that paragraph something that isn't there. Also, it's hard to figure out how "the vast majority come from both natural sources AND human sources" contradicts "there are naturally occurring greenhouse gases, there are man-made greenhouse gases." The two say basically the same thing. --Minasbeede 23:04, 1 October 2007 (UTC)


In my view they say opposite things, the current version appears to suggest that some gases are entirely natural and some gases are entirely man-made, three seperate users mentioned this issue in September, even if you do not see the problem it is obvious that other people can, so it needs to be changed. If you have a problem with what I have suggested please say what it is and we can discuss it, but the article can not stay as it is.


The current version reads "Some greenhouse gases occur naturally in the atmosphere, while others result from human activities"

perhaps you can better see my point if you compare that to the sentence 'Some cars are made in France, while others are made in Germany' Restepc 23:27, 1 October 2007 (UTC)

Given that cars are made in Japan, the United States, Mexico, Canada, Russia, and lots of other places that's a really bad example.
The paragraph could be very explicit, perhaps, and say that "of the greenhouse gas molecules that are in the atmosphere some arose naturally while others were man-made" - but that's cumbersome. Also, except for species that are man-made, once the gas is in the atmosphere there's no way to tell, for gases that could be of either origin, what the origin of a particular molecule is.
The paragraph isn't meant to divide greenhouse gas species (methane, CO2, etc.) into two mutually exclusive types, it's just meant to indicate that of the greenhouse gases in the atmosphere some arise naturally, some are man-made. It's not a grand, definitive exposition of the sources of greenhouse gases, it's just something that indicates greenhouse gases arise both ways: naturally, and from the activities of man. If three separate users misinterpreted the paragraph then perhaps it can be better written but the solution does not seem to lie in the direction of identifying gases according to whether they're natural, man-made, or both. That's not what the paragraph is meant to do: it's just an introduction. Reciting all the various gases and saying whether they're natural, man-made or both (as they occur in the atmosphere) makes the paragraph cumbersome. --Minasbeede 00:00, 2 October 2007 (UTC)


How about something like

"Greenhouse gases are components of the atmosphere that contribute to the greenhouse effect. The majority of greenhouse gases come mostly from natural sources but are also contributed to by human activity. Greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, and ozone."

Or possibly to be more specific this would be better

"Greenhouse gases are components of the atmosphere that contribute to the greenhouse effect. The five most common greenhouse gases come mostly from natural sources but are also contributed to by human activity. Greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, and ozone."

Unfortunately I'm not sure if that's entirely correct...I don't know the figures for Ozone.... Restepc 02:06, 2 October 2007 (UTC)

Why do almost all the graphs lie?

Almost all graphs show a significant increase in C02 in the atmosphere. But the graph only goes from 300 something to 400 something. This will give the graph an exponential look, instead of a logaritmic look.

Basicly it makes the graph look more dangorus. —Preceding unsigned comment added by Vifteovn (talk • contribs) 09:31, 14 September 2007 (UTC)

The concern isn't over the total amount of greenhouse gases, the concern is over the increase in greenhouse gases due to human activity. That increase is exponential, is it not? It's not T that is the concern, it's ΔT - and ΔT is mostly driven by Δ(greenhouse gases.) The Δ is positive for both. --Minasbeede 18:15, 30 September 2007 (UTC)


I wouldn't say lie, but they are certainly highly misleading if I had the skills to edit the graphs I would. Restepc 05:48, 1 October 2007 (UTC)

Should the "temperature increase" graph be altered to start at 0° Kelvin (making it much taller)? That would make far more obvious how small a 1° change in average temperature is. The Kelvin temperature scale is the proper scale to use when considering the relative magnitude of the change. It's also the proper scale to use for gases and the proper scale to use when discussing (photon) radiation. --Minasbeede 14:20, 1 October 2007 (UTC)


That's an ad hominem argument MB. —Preceding unsigned comment added by Restepc (talk • contribs) 22:27, 1 October 2007 (UTC)

Whoops, forgot to sign Restepc 22:56, 1 October 2007 (UTC)

Name that hominem. --Minasbeede 22:59, 1 October 2007 (UTC)


eh, too tired to explain....just headed to bed....let's sort out one issue at a time :) Restepc 23:34, 1 October 2007 (UTC)


If the graph has legible labels on the axes, then I don't have a problem with adjusting the ranges graphed to make plain the trends. However, most of the graphs in this article have illegibly tiny axis labels, with the result that the graphs are highly misleading to the casual reader. The effect is to exaggerate the rates of change of whatever is being graphed, and promote a particular POV. That needs to be fixed. NCdave (talk) 22:16, 15 March 2008 (UTC)
I run a fairly high resolution on a small screen, and most of the graphs are visible and readable to me (with the only exceptions being the one for water vapor and the one for global GHG trends - which both compress a lot of data into a rather limited area). Which graphs do you think are "exaggerating the rates"? --Kim D. Petersen (talk) 00:09, 16 March 2008 (UTC)
I use a very good 19" LCD monitor at its natural 1280x1024 resolution, with normal-sized fonts. Viewing the article in Firefox at normal text size, the main article text looks like 10pt. The image captions look like 9pt. Anything smaller than that is hard to read. The absolute lower limit of legibility is about 5pt, and my guess is that many users will not be able to read 5-6pt text at all. Though "fine print" text in the 6-8pt range is legible, with effort, it is so hard to read that many readers won't bother.
The text in the top graph is tiny, but legible. The smallest text is "(All Sources and Sinks)" which is about 5pt.
Most of the key text in the second image (Radiation transmitted by the atmosphere") is just barely legible. The tiniest is "Downgoing Solar Radiation" and "Upgoing Thermal Radiation" at the top, which are about 4pt. It is arguably "legible," but I think only because I already looked at the large version, and know what it says.
The smallest text in the third image (the pie charts) is illegible. It is the text at the very bottom, and it appears to be about 3pt.
The fourth image is the "Equilibrium global mean temperature increase above preindustrial" graph. The text is about 5pt, and just barely legible, if I strain.
The text in the fifth image, with the world map, is about 1-2pt, and completely illegible.
The text in the sixth image also varies from about 2pt to about 5pt. Most of it, including the axis labels, is too tiny to read. If you view the large version, you can see that the Y-axis does not start at zero, which is a problem when the axis labels are illegible.
Most of the text in the seventh image ("Global fossil carbon emissions") is about 5pt in size, and just barely legible, if I strain.
The text in the eighth image, with the world map, is about 1-2pt, and completely illegible.
The five graphs in the ninth image "Global trends in major greenhouse gases to 1/2003," have both captions and axis labels which are 1-2pt in size, and far too tiny to read. All of them have Y-axes which start at above zero, thus exaggerating the trends that they illustrate. These are the worst, and the problem is exacerbated by that fact that these are arguably the most important graphs in the article.
The text in the tenth image, with the world map, is about 1-2pt, and completely illegible.
The text in the eleventh image (maps relating to carbon monoxide) is about 2-4pt, and much of it is illegibly tiny. NCdave (talk) 01:36, 16 March 2008 (UTC)

I think that there being text too small to read in such linked graphs is just something we're going to have to live with, however I do strongly agree with NCdave that the "Global trends in major greenhouse gases to 1/2003," graphs become misleading because of this factor, as it is fairly safe to assume that a casual reader will think the graphs start at 0. Restepc (talk) 10:32, 16 March 2008 (UTC)

Please define what 0 (on the axis) should be.
For CO2 should it be 280ppm (just about the static amount over this interglacial 10K+ years)? Or should it be 180ppm (the lowest amount of CO2 over the last 650K+ years). Or should it be 0ppm (a value that has never been seen on Earth (afaik as long as we've had an atmosphere) - and has no realistic relationship with trends or amounts)? --Kim D. Petersen (talk) 23:55, 16 March 2008 (UTC)


As I said, I think it's fairly safe to assume that a casual reader will assume the graphs start at 0, as in 0ppm....the axis labels are too small to read, so the debate currently isn't really what levels they should be at, but rather what impression a layman is currently going to get of what they start at, which is fairly obviously going to be 0ppm....Restepc (talk) 00:03, 17 March 2008 (UTC)

If a casual reader gets that impression, then he is not interested in the graph. Since a perusal of the graph, and the text would quickly fix that misconception.
What is more important is not to indirectly mislead, by placing an arbitrary 0 on a graph, which has absolutely no relation to the context or concept.
Lets take a (extreme but valid) example. Should a graph of temperature start at 0°F, 0°C or 0°K?
By choosing absolute 0 no matter what we are measuring, you are biasing the graph, by not representing the data correctly in context. NCDave quite correctly observed that its the trends, and its relation to the concept measured that needs to be represented. --Kim D. Petersen (talk) 00:21, 17 March 2008 (UTC)


Not scientifically valid perhaps, but nevertheless it is what the casual reader will assume, and it is for those readers that wikipedia should be written...and I can't see the relevance of your temperature example, why not use what we're actually talking about instead?
Perhaps the best way to solve the problem would be to enlarge the graphs as they appear on the main page.....or replace them with one(s) which can easily be read, as the current situation does indirectly mislead.
Restepc (talk) 00:39, 17 March 2008 (UTC)
In which way is it indirectly misleading. If the graphs are presented correctly according to the concept that they describe - ie. no exaggeration of trends, in a scale that presents them without taking a stand. Then i really can't see what your problem is.
As an example take the first graph (carbon dioxide concentration) - that Y-axis is chosen so that if you wanted to display the CO2 content over the last 10K+ years - it would fit. Choosing another axis (for instance starting at 0ppm) on the other hand would indirectly mislead. --Kim D. Petersen (talk) 22:49, 17 March 2008 (UTC)
I think you misunderstand me, the graphs themselves are fine, or at least acceptable (if I was going to be pedantic I'd suggest minor changes but it's not high on my list)...but only when viewed correctly, I don't object to the scale used currently, I'm simply saying that because they're too small to read, people are extremely likely to assume that they start at 0, which considerably exaggerates the trend, giving people like Vifteon a legitimate reason to accuse the article of 'lying' Restepc (talk) 10:30, 18 March 2008 (UTC)

This entire discussion is weird. The graphs have their axes scaled so that they fit and there isn't loads of white space. This is obvious. If you think the legends are too small, feel free to make them bigger, or source better ones, or whatever William M. Connolley (talk) 23:16, 17 March 2008 (UTC)

In the absence of legible axis labels, zero should be zero. Otherwise the graphs are severely misleading, and exacerbate the POV-bias of the article, by making modest increases appear to be enormous increases.
However, I do not believe that it is necessary for the big versions of the graphs to be identical to the small ones. We could make small ones with illegible axis labels, and the Y-axis starting at zero, which link to the current big versions with legible axis labels, and the Y-axis starting at greater than zero. NCdave (talk) 06:02, 19 March 2008 (UTC)
I don't know what you are talking about. Of the images in this article, only three include graphs with an offset zero, and even though the writing is small, in each case I have no problem telling that they have an offset zero from the small graph. Dragons flight (talk) 06:23, 19 March 2008 (UTC)
Dragons obviously have much better eyesight than middle-aged men. NCdave (talk) 07:49, 19 March 2008 (UTC)
I think you must have different settings to us dragon, the simplest way to solve this problem would surely be to slightly enlarge the picture in question....perhaps rearranging the graphs slightly, have CO2 large and at the top, with the other 4 in pairs underneath.....in the long term though I'd suggest getting different graphs entirely, these only go back 20 or 30 years, which doesn't strike me as particularly useful....Restepc (talk) 10:43, 19 March 2008 (UTC)