Climate Change Skeptics Rebuffed: Cosmic Rays Have No Link to Cloud Formation on Earth

Thursday, October 09, 2008 by: David Gutierrez, staff writer
Tags: climate change, health news, Natural News

(NaturalNews) Cosmic rays do not appear to have any effect on the world's climate, researchers at a meeting of the European Geosciences Union have reported, dealing a blow to climate change skeptics.

Some climate change deniers have said that if the mean temperatures of the planet are rising, it is not due to increasing concentrations of greenhouse gases, but rather to changes in solar radiation. When "solar wind" is strong, supercharged particles known as cosmic rays are not as able to reach the Earth. Climate change skeptics have suggested that cosmic rays play a crucial role in cloud formation, meaning that an increase in solar radiation would ultimately lead to fewer clouds and higher global temperatures.

To test this hypothesis, Jon Egill Kristjansson of the University of Oslo, Norway, examined satellite images of the skies above southern oceans, where the low concentration of industrial pollutants means that natural changes in cloud properties are easily observed.

"We have short-term changes called 'Forbush decreases', caused by eruptions on the Sun, where cosmic ray flux can decrease dramatically over one or two days and then gradually recover," Kristjansson said.

Kristjansson measured cloud cover, water droplet size and the amount of water held by clouds both before and after 13 Forbush decreases between 2000 and 2005. The fluctuation of cloud properties appeared to be unaffected by changes in cosmic rays, with clouds thickening after a drop in cosmic rays as often as they thinned.

"I think that as a factor in climate change, it's pretty clear that we don't have any indication at this point that this is important at all," Kristjansson said.

"Whereas global mean temperatures have been rising steadily over the last 30 years, we see that the cosmic ray flux has been steady," he added.

Kristjansson's findings are consistent with those of another recent study, which found no connection between cosmic rays and cloud formation. In a third paper on the link between the rays and global warming, presented at the same conference as Kristjansson's paper, cosmic rays were found to have no net effect on the temperatures at the planet's poles.

Sources for this story include: news.bbc.co.uk.