Global Warming

Small Volcanic Eruptions Slow Global Warming

Small volcanic eruptions are also responsible for the global warming slowdown since 2000, claims a new study. Over the years, the impact of small volcanic blasts was overlooked because their planet-cooling particles cluster below the reach of satellites, scientists said.

The study included small volcanic eruptions from 2000 to 2013. It stated that small eruptions would have discharged larger amounts of sulfur dioxide gas into the upper atmosphere than previously thought.

Sulphur dioxide gas cools the Earth by blocking some of the Sun's solar radiation and reflecting it back into space. The stratosphere is the second layer of Earth's atmosphere and is above the one in which humans live (the troposphere).

The study said one or two eruptions each year could help prevent a doubling of the solar radiation reaching Earth.

"The effects of these smaller volcanoes is part of the solution to the warming hiatus or why the climate models didn't predict that this was going to happen," said David Ridley, lead author the study and atmospheric scientist at the Massachusetts Institute of Technology.

These small volcanic eruptions create droplets of sulfuric acid that combines with oxygen in the upper atmosphere and stay there for a long time. They also reflect sunlight away from the Earth.

Ridley and his colleagues also traced the source of aerosols found in the lower stratosphere and put there by volcanic eruptions early this century. The eruptions were much smaller than 1991's massive Mount Pinatubo outburst in the Philippines, which had a noticeable cooling effect on the global climate.

Findings indicate a lot of small eruptions do pump aerosols into the stratosphere, especially eruptions of high-latitude volcanoes.