A study led by researchers at the University of Colorado has
determined that the pace of planet warming in the first decade
of this century was slowed by volcanic activity, and not by
industrial activity in Asia, as was previously believed.
Previous research in 2009 had suggested that an increase in
stratospheric aerosols tied to a 60 percent increase in sulfur
dioxide emissions over China and India had negated about 25
percent of the global warming that scientists attribute to
greenhouse gas emissions. That cooling effect occurs when sulfur
dioxide emissions rise 12 to 20 miles to the stratospheric
aerosol layer of the atmosphere. There, chemical reactions
create sulfuric acid and water particles that reflect sunlight
back into space. Now, research led by study author Ryan Neely,
conducted as part of his doctoral thesis at CU, has shown that
global warming from 2000 to 2010 was tamped down by sulfur
dioxide from volcanic eruptions, not industrial emissions in
China and India, where such activity has greatly