Henrik Svensmark

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Henrik Svensmark is a physicist at the Danish National Space Center in Copenhagen who studies the effects of cosmic rays on cloud formation. His work is connected to considerable controversy in the area of the global warming issue. He has highlighed how it conflicts with the theory held by some that the effects of human activity on rising temperatures are more significant than solar activity.

Henrik Svensmark

1 Career
2 Theory of climate change
3 Further studies
4 Selected publications
- 4.1 Book
5 Awards
6 References
7 External links

[edit] Career

Svensmark, director of the Centre for Sun-Climate Research at the Danish Space Research Institute (DSRI), a part of the Danish National Space Center, previously headed the sun-climate group at DSRI. He also held postdoctoral positions in physics at three other organizations: University of California, Berkeley, Nordic Institute for Theoretical Physics, and the Niels Bohr Institute.^[1]

In 1997, Svensmark and Eigil Friis-Christensen popularised a theory that linked galactic cosmic rays and global climate change mediated primarily by variations in the intensity of the solar wind, which has been termed cosmoclimatology. This theory had earlier been reviewed by Dickinson.^[2] The small-scale processes related to this link were studied in a laboratory experiment performed at the Danish National Space Center (paper published in the Proceedings of the Royal Society A", February 8, 2007).

Svensmark's research downplays the significance to which atmospheric CO₂ may affect global warming.

[edit] Theory of climate change

In 2007, Svensmark and Nigel Calder published a book The Chilling Stars: A New Theory of Climate Change which introduced the theory that cosmic rays "have more effect on the climate than manmade CO₂":

During the last 100 years cosmic rays became scarcer because unusually vigorous action by the Sun batted away many of them. Fewer cosmic rays meant fewer clouds--and a warmer world.^[3]

A documentary film on Henrik Svensmarks theory, The Cloud Mystery, was presented by MortensenFilm.dk ^[4]early in 2008.

[edit] Further studies

Mike Lockwood of the UK's Rutherford Appleton Laboratory and Claus Froehlich of the World Radiation Center in Switzerland published a paper in 2007 which concluded that the increase in mean global temperature observed since 1985 correlates so poorly with solar variability that no type of causal mechanism may be ascribed to it, although they accept that there is "considerable evidence" for solar influence on Earth's pre-industrial climate and to some degree also for climate changes in the first half of the 20th century.^[5]

Svensmark's coauthor Calder responded to the study in an interview with LondonBookReview.com, where he put forth the counterclaim that global temperature has not risen since 1999.^[6].

Later in 2007, Svensmark and Friis-Christensen brought out a Reply to Lockwood and Fröhlich which concludes that surface air temperature records used by Lockwood and Fröhlich apparently are a poor guide to Sun-driven physical processes, but tropospheric air temperature records do show an impressive negative correlation between cosmic-ray flux and air temperatures up to 2006 if a warming trend, oceanic oscillations and volcanism are removed from the temperature data. They also point out that Lockwood and Fröhlich present their data by using running means of around 10 years, which creates the illusion of a continued temperature rise, whereas all unsmoothed data point to a flattening of the temperature, coincident with the present maxing out of the magnetic activity of the Sun, and which the continued rapid increase in CO₂ concentrations seemingly has been unable to overrule. This reply has so far not been published in a peer-reviewed journal.

Other organizations, influenced by Svensmark's work, plan to build on the Danish findings. CERN, the European Organization for Nuclear Research in Geneva, started a multi-phase project in 2006, including rerunning the Danish experiment, only CERN plans to use an accelerator rather than reliance on natural cosmic rays. CERN's multinational project will give scientists a permanent facility where they can study the effects of both cosmic rays and charged particles in the Earth's atmosphere.^[7]. The project was named CLOUD (Cosmics Leaving OUtdoor Droplets)

In April 2008, Professor Terry Sloan of Lancaster University published a paper in the journal Environmental Research Letters titled "Testing the proposed causal link between cosmic rays and cloud cover"^[8], which found no significant link between cloud cover and cosmic ray intensity in the last 20 years. Svensmark responded by saying "Terry Sloan has simply failed to understand how cosmic rays work on clouds".^[9]

However, Dr. Giles Harrison of Reading University, who has worked on the issue, has described the work as important "as it provides an upper limit on the cosmic ray-cloud effect in global satellite cloud data". Harrison's research^[10], which studied the UK only, has suggested that cosmic rays make only a very weak contribution to cloud formation.

[edit] Selected publications

Henrik Svensmark (1998). "Influence of Cosmic Rays on Earth's Climate". Physical Review Letters 81: 5027–5030. doi:10.1103/PhysRevLett.81.5027.

Henrik Svensmark, Jens Olaf P. Pedersen, Nigel D. Marsh, Martin B. Enghoff & Ulrik I. Uggerhøj (2007). "Experimental evidence for the role of ions in particle nucleation under atmospheric conditions". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 463: 385–396. doi:10.1098/rspa.2006.1773.