Researchers find a surprisingly welcomed side-effect of volcanic eruptions

Climate experts speculate as to why global atmospheric temperatures have slowed their increases in the last decade and a half, and now a new study suggests that aerosols released from small volcanic eruptions may play a role.

by John Tyburski

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First published at Daily Digest News on November 20, 2014

There is no question that the public discussions of and, some might say, the hype surrounding global warming has steadily increased. One conundrum confronting proponents of manmade climate change, however, is that the rate at which atmospheric temperatures are increasing has slowed since the year 2000, something experts call the “global warming pause.” So-called greenhouse gases have continued to accumulate, however.

A new study published in the October 31 issue of Geophysical Research Letters suggests that small volcanic eruptions may have released enough material into the atmosphere to slow the increase in temperatures. Up to this point, such volcanic events were not considered; the particles released generally cluster below the level of detection by climate-monitoring satellites.

According to the authors of the report, led by MIT’s David Ridley, satellite assessments were missing about 30 percent of the particulate matter shot out of volcanoes, emissions the scientists are calling aerosols. The aerosols contain sulfur dioxide that once in the stratosphere, cool the Earth by blocking some of sun’s radiation from reaching the inner atmosphere.

The total aerosol impact for the globe, when included in a simple climate model, yields a predicted cooling effect of 0.09 to 0.22 degrees Fahrenheit since 2000. Even this impact is not large enough to completely explain the global warming pause. However, Ridley and others do believe the volcanic aerosols play a part in a multifactorial explanation.

“This doesn’t necessarily mean that every eruption will be able to get sulfur dioxide into the stratosphere and form aerosols, but they are just neglected entirely in the climate models from the [Intergovernmental Panel on Climate Change],” said Ridley. “The fine nuances make quite a big difference in these eruptions.”