Climate Change May Counteract Cooling Effect of Powerful Volcanic Eruptions

A new study from the University of British Columbia revealed that global warming brought about by climate change may counteract the cooling effect of volcanic eruption in the next century.

The study, published in the Journal of Geophysical Research-Atmospheres, showed that warming temperatures will make the lower levels of the atmosphere to expand. As a result of the expansion, sulfur gases released during a volcanic eruption will have a hard time reaching a layer called stratosphere.

"Volcanic eruptions tend to counteract global warming but as the planet heats up and our atmosphere changes, we've found that fewer eruptions will be able to reflect the sun's radiation," explained Thomas Aubry, a PhD student studying climate and volcanoes and lead author of the study, in a press release. "It will be harder for the volcanic gasses to reach high enough into atmosphere to help cool the planet."

For the study, the researchers calculated the impact of volcanic gases by analyzing models of volcanic eruptions and global climate. The researchers found that the present trend of global warming could decrease the amount of volcanic sulfur gases in the stratosphere by 2 to 12 percent in the next 100 years. Furthermore, The researchers predict that decrease of sulfur gases in the stratosphere will reach about 12 to 25 percent by the end of 22^nd and 23^rd centuries.

The stratosphere is about 10 to 15 kilometers from the Earth's surface. Volcanic sulfur gases that reached the stratosphere will react with water to from aerosol particles. These particles can linger in the stratosphere for one or two years, reflecting sunlight and heat back to the space and cooling the planet in the process.

However, global warming could limit how high the volcanic sulfur gases could reach. In the lower levels of troposphere, volcanic sulfur gas can quickly turned into aerosols and clouds and precipitate back down to Earth as rain or snow, losing its long-term cooling effect on the planet.