A Dusty Ice Age Trigger Looks Too Weak

Abstract

PALEOCLIMATOLOGYMost climate researchers believe that the 100,000-year cycle of the ice ages is driven by the changing ellipticity of Earth's orbit, but one physicist has argued that the changing tilt of Earth's orbital plane dips it in and out of a cloud of climate-altering interplanetary dust. Now, on page [874][1], two planetary scientists report calculations suggesting that dust should indeed fall to Earth in a 100,000-year cycle matching the ice ages, but the amount involved appears to be too small to alter climate. [1]: http://www.sciencemag.org/cgi/content/short/280/5365/874