Tuesday, May 12, 2009
Computer Simulation Study Shoots Down Cosmic Ray Explanation for the Cause of Global Warming
There is more than enough evidence that human sources are the main cause of global warming to conclude that strong action is needed to reduce greenhouse gas emissions but one alternative explanation for the warming that has not been completely ruled out is known as the “cosmic ray hypothesis.” According to this explanation solar activity has an effect on cosmic rays which reduces cloudiness, thereby resulting in more sunlight reaching the surface of the earth which leads to increased warming. Science Daily reports that Peter Adams and Jeff Pierce, scientists from Carnegie Mellon University and Dalhousie University (Halifax, Canada), respectively, developed a computer model to test this hypothesis and reported in Geophysical Research Letters that there were not enough changes in the concentrations of particles affecting clouds to make any difference in the climate. Adams told Science Daily that he expects the results of the computer simulation to be challenged but thinks the results will withstand any questioning. The history of science is full of controversial explanations eventually proving to be correct but it appears this will not be the case for the cosmic ray hypothesis.