It is the sun that is the driving force of our climate...
The sun drives the global climate
It is the sun that is the driving force of our climate and so it makes sense that it has the biggest impact on our climate rather than anything that humans might be doing. The sun is therefore the most likely cause of global warming. Professor Henrik Svensmark, a physicist at the Danish National Space Center in Copenhagen argues that climate change is caused by solar activity.[[Louise Gray, 'Copenhagen climate summit: global warming 'caused by sun's radiation'', The Telegraph, 8/12/09, http://www.telegraph.co.uk/earth/copenhagen-climate-change-confe/6762640/Copenhagen-climate-summit-global-warming-caused-by-suns-radiation.html%5D%5D Solar activity, as determined by sunspot activity, is historically high being at its highest over the last 60-70 years for over 8000 years. Solar activity could affect climate by variation in the Sun's output or potentially through having an effect on cloud formation. Solanski et al. Sunspot numbers and cosmic ray fluxes... show correlations and anti-correlations with a number of reconstructions of the terrestrial Northern Hemisphere temperature, which cover a time span of up to 1800 years. This indicates that periods of higher solar activity and lower cosmic ray flux tend to be associated with warmer climate, and vice versa... This suggests that effects induced by cosmic rays may affect the long-term terrestrial climate. The positive correlation between the geomagnetic dipole moment and the temperature reconstructions provides further evidence favoring the cosmic ray influence on the terrestrial climate. [[I.G. Usoskin, S.K. Solanski, M. Schussler, K. Mursula, Solar activity, cosmic rays, and Earth’s temperature: A millennium-scale comparison, 1/10/05 http://cc.oulu.fi/~usoskin/personal/2004ja010964.pdf%5D%5D