A paper published online in Geophysical Research Letters on Mar. 1, 2013, claims that volcanic eruptions not pollution from coal burning in China and India is the major reason that the expected temperature increase from carbon dioxide induced global warming have been reduced by 25 percent from projected expectations over the last ten years.
The study, lead by Ryan Neely at the University of Colorado Boulder, suggests that the chemical reaction between sulfur dioxide produced by volcanic eruptions produce sulfuric acid and water particles 12 to 20 miles into the stratospheric aerosol layer of the Earth’s atmosphere and reflect sunlight back to space, cooling the planet.
The researchers provide conclusive data that indicates volcanic emissions have slowed the anticipated rate of global warming from carbon dioxide by as much as 25 percent over the last decade.
The measurements hinge on the optical depth of the stratospheric aerosol layer that has increased by four to seven percent since 2000.
The researchers do not claim that volcanic eruptions will save the Earth from the effects of global warming and climate change but rather indicate that volcanic eruption factors should be included in any prediction of temperature changes that result from global warming.
The scientists indicate that volcanic eruptions are not as predictable as the steady increase in carbon dioxide produced by the continuing increase in the burning of fossil fuels but the effect of volcanic global cooling should be realized and taken into account in long term assessments of climate change.