A team led by the University of Colorado Boulder looking for
clues about why Earth did not warm as much as scientists expected between 2000
and 2010 now thinks the culprits are hiding in plain sight -- dozens of
volcanoes spewing sulfur dioxide.
The study results essentially exonerate Asia, including
India and China, two countries that are estimated to have increased their
industrial sulfur dioxide emissions by about 60 percent from 2000 to 2010
through coal burning, said lead study author Ryan Neely, who led the research
as part of his CU-Boulder doctoral thesis. Small amounts of sulfur dioxide
emissions from Earth’s surface eventually rise 12 to 20 miles into the
stratospheric aerosol layer of the atmosphere, where chemical reactions create
sulfuric acid and water particles that reflect sunlight back to space, cooling
the planet.