Wednesday, January 21, 2009

Cosmoclimatology: 2 versions of new meme

CO2 induced global warming is a very successful meme these days. We still do not know if it is true or not, and we probably will not for quite some time, given the political implications (a typical trick of successful memes :D ).

But another rival meme is now contending the mind-space: cosmoclimatology.

Here are some articles pro and against the new meme:

Pro
''Climate is subject to influences by both natural and human forces, including greenhouse gases, aerosols, solar activity, and land use change.

Changes in the sun contribute to climate change. Solar activity has been exceptionally high in the 20th century compared to the last 400 years and possibly compared to the past 8,000 years. When solar activity is high, the flux of galactic cosmic rays is reduced due to increased magnetic shielding by the Sun. The cosmic rays may influence the Earth's climate through the formation of low-lying clouds.

In 1996 a surprising discovery was announced that the intensity of cosmic rays incident on the earth's atmosphere correlates closely with variations of global cloud cover [Svensmark and FriisChristensen 1996]. Clouds both reflect incoming and trap outgoing radiation, and they thus play an important role in the Earth’s radiation budget.
'' [source from 2009]

Against
''It is possible that GCRs do have an effect on climate through the modulation of clouds, but I don't think it is very strong. I also think that Svensmark's claims are wildly exaggerated, but most of my objection lies in the way the arguments have been presented in this A&G article. I have the impression that the A&G article comes from the same school as "The Skeptical Environmentalist", which also has been criticised for cherry picking references to make mere speculation appear as more solidly founded. To ignore aspects that don't fit the hypothesis is definitely not science. Neither is adjusting data so to provide a good fit without a solid and convincing justification.'' [source from 2007]

Both
[source from 2007]

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