THERE is a theory that the earth’s climate is influenced by cosmic rays that penetrate our atmosphere from outer space. In particular it is thought cosmic rays influence the production of cloud condensation nuclei with periods of higher cosmic rays penetration associated with more cloudiness. The power of what is known as the solar wind, the magnetic force associated with the sun, is thought to influence the extent to which these high-energy charged particles composed of protons, electrons, and ionized nuclei reach earth.
The theory has been based to a large extent on correlations between climate and sunspot cycles. There is now a research effort to establish a physically-plausible link between cosmic rays, clouds and climate including through laboratory experiments in clouding at the Cern Cloud Facility in, Geneva, Switzerland. The theory and the experiments are explained in ‘Cosmic Rays and Climate’ by Jasper Kirkby, Surveys in Geophysics, Volume 28, pages 333-375.
I know of no equivalent research effort looking at establishing a causal link between carbon dioxide and climate.
This paper by Dr Kirby was first discussed here in a blog post by Paul Biggs on May 21 this year. I’ve only just properly discovered it – and thought it so good you should read about it a second time. I posted ‘Cosmic Rays, Clouds and Climate (Part 1)’ on April 13, 2008.