New research has dealt a blow to the skeptics who argue that climate change is all due to cosmic rays rather than to man-made greenhouse gases. The new evidence shows no reliable connection between the cosmic ray intensity and cloud cover.
Lauded and criticised for offering a possible way out of the dangers of man made climate change, UK TV Channel 4's programme "The Great Global Warming Swindle", broadcast in 2007, suggested that global warming is due to a decrease in cosmic rays over the last hundred years.
This would cause a decrease in the production of low clouds allowing more heat from the sun to warm the Earth and cause global warming.
Research published today, Thursday 3 April, in the Institute of Physics' Environmental Research Letters shows how a team from Lancaster and Durham Universities sought a means to prove the correlation between the ionizing cosmic rays and the production of low cloud cover.
Previous research had shown a possible hint of such a correlation, using the results of the International Satellite Cloud Climatology Project, and this had been used to propose that global warming was all down to cosmic rays.
The new research shows that change in cloud cover over the Earth does not correlate to changes in cosmic ray intensity. Neither does it show increases and decreases during the sporadic bursts and decreases in the cosmic ray intensity which occur regularly.
One such very large burst caused the magnetic storm which blacked out the power in Quebec in 1989.
Professors Sloan from Lancaster University and Wolfendale from Durham University write, "No evidence could be found of changes in the low cloud cover from known changes in the cosmic ray ionization rate."