Study Challenges Cosmic Ray-Climate Link

摘要

If rising levels of greenhouse gases aren't pushing up global temperatures, as contrarians argue, what else could be? The leading alternative has been a fickle sun, and the sun's most likely-or most heavily promoted-agent of change has been cosmic rays. Now scientists have published the first comprehensive modeling of how the sun might indirectly thin cloud cover and thus warm the planet. It suggests that cosmic rays are not up to the task by two orders of magnitude. "It's a really good first study," says modeler Dominick Spracklen of the University of Leeds, U.K., but "the first attempt is always going to be uncertain. There's going to be debate."