Talk:Acid rain

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[edit] Picture

I think a good picture for the article would be one of a forest (and trees) damaged by the acid. You would have to find one that allows fair use though unless you have taken one yourself in such an area.

[edit] Headline text

This is an excellent scientific treatment. Thanks,

Now, can anyone describe what industry and goverment are doing to ameliorate the problem? I'd like to see at least a reference to emissions trading or fines or scrubbing or reductions of output or whatever.

Ed Poor, Tuesday, June 11, 2002

[edit] Accuracy/POV

I believe that this idea is a world wide epidemic and it needs to be stoped at all costs.this needs to be related to polution and global warming. (cole)

  I am tempted to put a tag disputing either the accuracy or the POV of the article, but I won't as of yet because that might prove to be quite controversial.


Furhermore, I miss the placing of the widespread attention to this perceived phenomenon withing the context of the envrionmental-conscious 80s.

Also, there should be some descriptions of Nictrification, and attention paid to the publications in Nature of january 27th 1994 regarding the role of calcium potassium Sodium and magnesium in counterbalancing the SO2 en NOx emitions.

There is a lot more to be said on this topic, quite a lot of the suppositions about Acid rain were alledgedly based on junkscience but sadly I miss the neccesary background to contribute in a sensible way to the article. --Lomedae 18:54, August 23, 2005 (UTC)

I agree that this article should be tagged for accuracy or POV.

"Since public interest groups can retire the licenses by purchasing them, the net result is a continuously decreasing and more diffused set of pollution sources. At the same time, no particular operator is ever forced to spend money without a return of value from commercial sale of assets"

Which emission trading agreements allows public interest groups to buy licences? Some examples would be good. The statement on the effectiveness of emission trading systems is an opinion, rather than fact and should be removed. For a full explanation of its merits, or otherwise, the page points to emission trading.

POV should definitely be removed. The favourable references to emission trading should be removed, but I'll first give the emission trading entry a makeover. Can someone provide a reference to the bold assertion of the environmental advantage of nuclear power? If not, I'll remove the reference. I suspect it is a half-truth at best. Jens Nielsen 10:43, 15 January 2006 (UTC)

[edit] formation of H2SO4

sulfur dioxide and nitrogen oxides ... diffuse into the atmosphere and react with water to form sulfuric and nitric acids

Sulphur dioxide is oxidation state 4. Sulphuric acid is oxidation state 6. It can't be a case of just reacting with water, there must be further oxidation. Likewise, which nitrogen oxides? I think largely NO and NO2 (oxidation states 2 and 4). Nitric acid is oxidation state 5.

TerraGreen 12:26, 8 December 2005 (UTC)

Sulfur dioxide (S4+) plus water produces sulfurous acid (S4+)
SO2 + H2O ==> H2SO3
Sulfur trioxide (S6+) plus water produces sulfuric acid (S6+)
SO3 + H2O ==> H2SO4
Nitrogen oxide reactions seem a bit more complicated. Vsmith 13:23, 8 December 2005 (UTC)
According to my book, nitrogen oxide forms acid rain by the following reaction.
nitrogen oxide + water → nitric acid + nitrous acid
Is it correct?
Also, I want to know how sulfur trioxide forms in air? According to my teacher, sulfur trioxide cannot be formed without catalyst even there is excess oxygen.
My teacher also told me that dissolving sulfur trioxide into water is very exothermic (and that's why it is not done in the Contact Process). If sulfur trioxide in air dissolves to form acid rain, will the rain water be heated and vaporized?Momoko


The current explanation is misleading. A large fraction of oxidation of SO2 occurs in raindrops and involves reactions in the liquid phase with hydrogen peroxide, ozone and manganese. Most emissions are in the form of SO2 or H2S. Oxidation in the gas phase occurs via reaction with the hydroxyl radical. I will improve this when I get time (unless someone else gets there first. There are several steps to the reactions so I need to get my atmospheric chemistry book out to check they are right. In the meantime I'll remove the misleading information.
On nitric oxide the main reaction is in the gas phase NO2 + OH -> HNO3. Another reaction is the nightime process of N2O5 reacting with water on the surface of particulate to give nitric acid.--NHSavage 08:56, 21 January 2006 (UTC)
This section had recently been changed incrrectly with the reation of sulfur trioxide with water changed to sulfur dioxide. This meant it resembled the old incrorrect version. there was a lot of vandalism on the article and I missed this important change which happened 31st Oct. sorry about that. I have now restored the correct version of this reaction. Thanks to JKleo for spotting that one.--NHSavage 20:50, 26 November 2006 (UTC)

[edit] Criteria has changed from 5.6 to 5.0

The pH of "normal" rain has traditionally been given a value of 5.6. However scientists now believe that the pH of rain may vary from 5.6 to a low of 4.5 with the average value of 5.0. [1]

To be considered acid precipitation, the precipitation has to have a pH of 5.0 or lower. [2]

Paleorthid 18:30, 26 December 2005 (UTC)

may vary from 5.6 to a low of 4.5 with the average value of 5.0. Huh? Wouldn't the average be 5.05? Caesardude 02:10, 24 May 2006 (UTC)

Huh? Wouldn't the average be 5.05? Depends if you're thinking of the mean or the median. One would assume that the median is the best approach to this situation.

[edit] Soil effects poorly documented

However, data to determine changes in soil characteristics (due to acid rain) are generally lacking.

Acid-base Characteristics of Soils in the Adirondack Mountains, New York

Paleorthid 23:24, 29 December 2005 (UTC)

That abstract is very unclear. I suspect it may mean that the data for the Adirondack Mountain is lacking rather than information in general. For the UK there is certainly much data. See chapter 5 of NEGTAP final report.--NHSavage 20:09, 11 September 2006 (UTC)

[edit] Cleanup

The part that says that it needs a cleanup needs it badly. It makes my eyes go all funny.


Someone please have a creaful look at the contents, plz. Thanks. --Bhadani 09:57, 12 January 2006 (UTC)

I agree this needs a lot of work. From looking at it carefullly it looks like a personal essay. It was posted on its own entry without any work to make it appropriate. I think it needs to be hacked down to a minimum so that the useful information can be put in and the rest removed. I'll try and get around to this but I am worling on Methane at the moment.--NHSavage 16:11, 21 January 2006 (UTC)
Hacked. Comments welcome.--NHSavage 21:38, 21 January 2006 (UTC)

[edit] Source needed for technical detail added

Removed from article:

The thickness of embedded SO2 and NO2 layers in marble is a meassure of the rate at which a material is attacked by this type of pollution. Calculated constant rates allow the thickness of embedded layers to be calculated over a wide range of SO2 and NO2 concentrations. Experiments have shown that, even in the presence of excess atmospheric NO2 over SO2, the amount of CaSO4 produced excess that of Ca(NO3)2, indicating that SO2 has a stronger weathering effect on marble relative to NO2.

First, this kind of detail needs a source - Experiments have shown... won't cut it here. Also the relative solubilities of calcium nitrate vs calcium sulfate should be discussed - presumably they were in the orig. source? Finally, why the bold - is this bit that critical? Vsmith 21:37, 4 February 2006 (UTC)

[edit] Effects on metal

I've read on random websites that there is an effect on iron and other metals. i might be able to add some after some research but this needs to be mentioned.

[edit] Major edit

I've been working on a fairly major edit of this article and I have now put it up. Feedback is welcome.--NHSavage 21:09, 17 February 2006 (UTC)

[edit] Need for proof

Cut from intro:

The resulting increased acidity in soil and waterways has proven to be harmful to fish and vegetation.

The article provides no source for this claim, let alone any "proof". However, it is an article of faith among radical environmentalists.

Would someone please provide a source for the claim that there is proof?

And if they have time, would they also please summarize any evidence this source provides? I'm looking for things like:

  • Acid rain has been observed to increase the acidity of soil and waterways.
  • This increased acidity has cause measurable harm to fish and vegetation.

Better yet would be actual numbers, e.g., Lake Michigan's pH went from 5.0 to 4.0; and then the population of lake trout went from 2 million down to 5,000 (or whatever). --Uncle Ed 21:57, 9 March 2006 (UTC)

[edit] Some quotes about acid rain

  • Fred Singer: Among scientists acid rain is generally understood to present no hazards to human health. [3]
  • The scientific chain between emissions and acid rain consists of three links: It requires knowledge about the emission of polluting gases into the atmosphere, the acidity of precipitation, and the ecological effects on soils and water. The evidence for all three can best be described as confused and confusing. [4]
  • EPA: Researchers now know that acid rain causes slower growth, injury, or death of forests. [5]
  • Missouri state gov't: Many lakes in the Adirondack Mountains of New York and many streams in the Appalachian mountain region have lost trout and other aquatic life due to acid rain. [6]

EPA: "Food crops ... are not usually seriously affected because farmers frequently add fertilizers to the soil to replace nutrients that have washed away." [7]

[edit] Still looking for proof

Once again, I ask: what is the evidence that human-caused emissions of pollutants (like sulfur dioxide) has significantly increased the acidity of rain anywhere? Or that reducing emissions has decreased the acidity of rain?

I'm not questioning the theory - the chemical process seems rather straightforward. But I'm looking for something nontechnical which our readers can dig into. Something like:

  • 1920 - rain acidity in the U.S. Northeast was measured at pH of 6.4 by scientists with the Blah Blah Blah agency.
  • 1980 - after 60 years of sulfur dioxide emissions from power plansts in Ohio and neighboring states, rain acidity increased to a pH of 6.1 [Blah agency report, 1983].
One good place to start would be NEGTAP, 2001. Another good source of info is

EPA's page on acid rain effects. I am aware that this section still needs a lot of work though.--NHSavage 22:17, 14 March 2006 (UTC)

[edit] Political quotes

Peter F. Guerrero wrote a letter for a GAO report, saying:

  • Acid rain ... is largely the result of burning fossil fuels to generate

electricity. [It] can harm human health and damage forests, lakes, and streams.

  • The two major causes of acid rain [are] sulfur dioxide and nitrogen oxides from electric utility power plants that burn coal and other fossil fuels.
  • Sulfur dioxide and nitrogen oxide emissions return to earth (in a process called deposition) in various chemical compounds.
  • Total sulfur deposition includes sulfates in precipitation (called wet sulfates), dry sulfate particulates, and dry sulfur gas. Similarly, total nitrogen deposition includes nitrates in precipitation (called wet nitrates), dry nitrate particulates, and dry nitrogen oxides.

This looks almost exactly like what our article says - though I haven't checked it word for word yet. It's not a copyright issue as much as a "source" issue. We need to rely on scientific sources for facts. Or, failing that, on political sources for points of view. --Uncle Ed 14:40, 14 March 2006 (UTC)

[edit] "M"

In the gas phase reactions... what kind of (apparently inexistant) element is represented by the letter m? Please clarify.

--Dbs12693 00:45, 24 March 2006 (UTC)dbs12693

It represent any third body. In Earth's atmosphere this is almost always N2 or O2. If you consider the reaction with just two bodies reacting together to give a single product e.g. OH + NO2 = HNO3 then it is impossible to conserve both momentum and energy simultaneously just by looking at the velocity of the product. The extra energy becomes internal energy in the product and this will tear the new molecule apart unless it colides quickly with some other molecule 'M' to remove this energy. This M is the conventional representation of this process in chemical kinetics. This also has a big effect on the speed of the reaction, giving it a pressure dependence as well as a temperature dependence. I will try and a short note to this effect in the article soon (and I will have to think about writing an article for wikipedia on this as I can't find anything to link to).--NHSavage 08:23, 24 March 2006 (UTC)

[edit] Big revert

I have just reverted back to the version of the 29/3. Apart from a lot of vandalism two other changes have been made.

1) In the early 1800's, a famous inventor by the name of Janakan set forth to discover the chemical basis behind acid rain (UofT Acid Rain Catalogue, 1997). (by User:Thakkarbhavik).

I am prety sure this is spurious. I apologise if this is true but I have never heard of Janakan and a google search on his name and acid rain finds nothing relevant. If it is correct please explain what the (UofT Acid Rain Catalogue, 1997) is and how I can get a copy. --NHSavage 13:34, 9 April 2006 (UTC)

2) What can I do to help? (by lots of different anonymous users). This is general advice on "beign green", parts of it are not at all relevant to acid rain - e.g. go CFC free (especially as CFCs are now banned everywhere). As regards acid rain I suppose some of the changes in driving style are relevant as nitric acid is still a major problem. However it is really out of place.

3) History and trends section went AWOL after all the vandalism.

--NHSavage 13:34, 9 April 2006 (UTC)

[edit] Unoriginal

I don't know much about copyrights, but much of this article is taken word for word, including images, from http://www.epa.gov/acidrain/.

Caesardude 02:18, 24 May 2006 (UTC)

Thanks for pointing this out. However works of US government agencies are not copyright. If you click on either of the images you will see they are tagged as such. As for the text - the copyright status is the same although I'd prefer that we had clean text but I'm not sure which parts are the problem - I know I wrote large chunks of the chemistry parts myself from scratch.--NHSavage 07:08, 24 May 2006 (UTC)

[edit] Controversy

Does this article fairly describe both points of view, about whether acid rain has ever caused any harm and/or whether this harm is important enough to pass laws to reduce emissions and thereby reduce this harm? --Uncle Ed 15:15, 30 August 2006 (UTC)

I have added the EPA viewpoint (which I assume is mainstream) [8], followed by an opposing viewpoint (which I assume is minority). [9]

If this is "POV pushing", shoot me now! --Uncle Ed 15:26, 30 August 2006 (UTC)

Three ref's might be overkill. Please trim this down or summarize it. --Uncle Ed 18:28, 30 August 2006 (UTC)
I am a bit worried by this edit but I don't have time now to do a proper change to the article. In particular I am worried by the selective use of one sentance from the Environmental Literacy Council webpage ("the effects of acidic precipitation were not as great as once feared") which is taken out of context (elsewhere it mentions that 10% of eastern lakes and streams had been affected by acid deposition). This is a short summary of a 98 page report (which I have not read but will try and skim). It is also not really evidence to my mind that this organisation believes that acid depostion is not a serious issue. If the early fears were that every lake in the US would die then clearly the effects were not as bad as that. If there was serious damage to 10% of Eastern lakes then this seeems a big problem. I do not plan to make any edits immediately but I feel it is important that we do not give the impression of there being widespread skepticism about acid rain which I feel would be misleading.
Yes, all of this makes sense. I just spen some time going through the "ten year study", and I'm not sure that Singer's viewpoint is really justified by his reference to it. He might have a bone to pick, so we probably should not consider him "an objective source" but rather someone who "disagrees with the mainstream". --Uncle Ed 19:52, 30 August 2006 (UTC)
I also wonder if this really belongs in the lead section.--NHSavage 18:52, 30 August 2006 (UTC)
Removed from intro - ref to a '93 letter by Singer and a report based on a minute interview - not good sources, especially for the introduction. Vsmith 23:21, 30 August 2006 (UTC)

How about a controversy section?

  • Other sources disagree, such as retired atmospheric physicist S. Fred Singer.[1]
  • He wrote:
  • A major scientific study, conducted under government auspices, had demonstrated that most small lakes affected are naturally acidic and that forests are not harmed. This new scientific evidence was never disputed; it was simply ignored. [2]
  1. ^ Acid rain provides a prime example of a case where the policy response ignored sound scientific evidence. After government agencies spent over half a billion dollars on research, some 3,000 scientists from atmospheric physicists to ecologists concluded that acid rain was only a minor problem that posed not threat to human health and that the damage claims hall been vastly exaggerated. Science Under Siege, letter by S. Fred Singer in ENVIRONMENT, May 1997
  2. ^ The Costs of Environmental Overregulation by S. Fred Singer, from Human Events - August 7, 1993

I would place it near "Prevention". --Uncle Ed 16:43, 31 August 2006 (UTC)

What was the major scientific study referred to? A vague ref. and a cite to SEPP site aren't enough. Or did Singer not specify the study - just a bit weasely as is. Vsmith 16:56, 31 August 2006 (UTC)

[edit] Acid rain vs Acid precipitation

If you want to be picky about this the correct term is actually acid deposition - dry depostion of acidic compounds is also a major contributor to acidification. We should either use the common term (Acid rain) or the widest possible term. I favour acid rain.--NHSavage 18:38, 31 August 2006 (UTC)

Me too. By a mile. Sfahey 15:33, 1 September 2006 (UTC)
  • The term "acid rain" is commonly used to mean the deposition of acidic components in rain, snow, fog, dew, or dry particles. The more accurate term is "acid precipitation." (USGS)

If you want to disagree with the USGS, be my guest and move the article back. I'm easy-going. --Uncle Ed 19:04, 31 August 2006 (UTC)

I do actually disagree. "Acid deposition also includes direct deposition, in which acidic fog or cloud is in direct contact with the ground; and dry deposition, in which ions become attached to dust particles and fall to the ground". [10]. It is illogical to include dry deposition of acids in an article on acid precipitation. Dry deposition occurs in the abscence of precipitation (hence the name). Acid rain is the commonly used term so there is a case for this article to be called this (the original title). Otherwise it has to be Acid deposition.--NHSavage 19:09, 4 September 2006 (UTC)
Renamed. See WP:NAME as well.--NHSavage 10:54, 9 September 2006 (UTC)

[edit] NPOV dispute

Uncle Ed wrote when flagging this as NPOV: "should fairly describe whether acid rain has ever caused any harm and/or whether this harm is important enough to pass laws to reduce emissions and thereby reduce this harm"

Can we agree to narrow this down a bit? As I see it, the main issue which you see as not being neutral is the question of the cost/benefit analysis of emission reductions? Can we just label the section on "Prevention methods" as NPOV not the whole article? Your main concern with the "Adverse effects" section seems to be the lack of references - this is well flgagged up by the citation needed templates but it might be worth slapping a {{Unreferenced}} tag on it. I can start to work on providing references for this section in that case. The discussion of trends and their relation to emissions reductions is very poorly dealt with - I think there need to be seperate sections for the history of the research and the measured trends.

The "Prevention" section seems the ideal place to note any oppposition to emissions controls and probably the most controversy prone also. One of Singer's articles you cited actaully argues that it was right to make the initial effort to reduce emissions of acid precursors it is jus that the final 1% is too expensive to clean up. I am not an expert in this area but I would be suprised if there is not more controversy about this out there on this sort of level. Environemtal science only has to deal with a very complex system, political science has to cope with confliciting priorities and ideologies as well....

I hope this plan can give us a clearer way forward with this article--NHSavage 20:42, 5 September 2006 (UTC)

[edit] Reworked Adverse effects

I have stripped this section down to the bare bones of information all taken from the EPAs pages. I will now fill in some more detail from other sources. However I believe this is now better structured and has references for all the information here. Stuff that I removed I will try and verify from other sources and then put back in the article.--NHSavage 19:18, 12 September 2006 (UTC) nice interesting ... i like it

[edit] Typo?

I don't claim to be an expert in the field, but this passage in the introduction paragraph seems to include a couple of errors. First off, we have:

Acid rain is defined as any type of precipitation with a pH that is unusually low.

As a lower pH indicates a stronger acid this seems to make sense. A couple lines later we have:

Therefore a pH of >5.6 has sometimes been used as a definition of acid rain.

This seems to read a pH GREATER than 5.6 has been used to define acid rain. This seems irrational as a pH greater than 5.6 is approaching a neutral pH. A couple lines later we find the same issue again:

However, natural sources of acidity mean that in remote areas, rain has a pH which is between 4.5 and 5.6 with an average value of 5.0 and so rain with a pH >5 is a more appropriate definition.

Going to alter this to read a pH of <5.6 and pH <5. If this is incorrect, go ahead and revert back.

-Alazon

Went to change this and in the code for the page the symbols appear correctly. Since this seems to be a coding error somewhere, I substituted lesser than and less than for the < symbol.

-Alazon

hey watz ^ tree huggers (please dont get offendid im a tree huger too) l.o.l im in total shock to hear about acid rain i swear it makes me mad70.156.27.239 01:25, 29 November 2006 (UTC)ME THE TREE HUGER70.156.27.239 01:25, 29 November 2006 (UTC)

[edit] Headline text

[edit] Observational Database

A large observational database of many different atmospheric constituents including radicals 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

[edit] Forests and other vegetation

Somebody didn't finish their thought in the last sentence under Forests and other vegetation. Anyone know what they are talking about? Hburg 15:59, 3 February 2007 (UTC)


[edit] Acid rain does not cause deforestation

According to Julian Simon (The Ultimate Resource 2, pg 265/6) and Bjorn Lomborg (The Skeptical Environmentalist, pg 178-181) acid rain does not cause deforestation. Both cite the work of the National Acid Precipitation Assessment Program (the only longitudinal attempt to demonstrate causality, as opposed to correlation) which demonstrated that acid rain does not reduce sapling growth, across a number of species and a broad range of pH 6.0 - 3.5 (cf average pH of 4.2 for acid rain). See: Kulp, J.L. and Herrick, C.N. /The Causes and Effects of Acid Deposition./ Interim Assessment, National Acid Precipitation Assessment Program. Washington, D.C.: U.S. Government Printing Office, 1987. [11]. --Michael C. Price talk 02:03, 13 February 2007 (UTC)

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