Climate Change May Prevent Volcanoes From Cooling The Planet

New University of British Columbia (UBC) research shows that climate change may impede the cooling effect of volcanic eruptions.

Credit: Wikimedia Commons

“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,” said Thomas Aubry, a PhD student studying climate and volcanoes. “It will be harder for the volcanic gasses to reach high enough into atmosphere to help cool the planet.”

Aubry notes that while the planet continues to warm, scientists have observed a slight decline in the rate of global warming over the last 10 to 15 years. Previous studies have shown that this is partially caused by the number of large eruptions over the last decade that have sent sulfur gasses high up into the stratosphere.

For this study, Aubry, who is a PhD student in professor Mark Jellinek’s lab in the department of earth, ocean and atmospheric sciences, used models of volcanic eruptions and global climate to calculate the impact on gasses released from volcanic eruptions.

According to climate model projections and global warming, Aubry and his co-authors found the amount of volcanic sulfur gasses in the stratosphere will decrease anywhere from two to twelve per cent in the next 100 years. Longer term, they predict anywhere from 12 to 25 per cent less sulfur gas in the stratosphere by the 22nd and 23rd centuries. They say the range is large because it is difficult to predict future eruptions and future greenhouse gas emissions.

To determine the precise impact on the Earth’s surface temperature in the future will require further study. It also raises interesting questions about Earth’s history.

“Understanding this positive feedback loop has provocative implications for understanding climate variability in Earth’s past,” said Jellinek. “In particular, this mechanism may have contributed to Earth’s entry into a long period of global glaciation around 700 million years ago, a theory known as the Snowball Earth hypothesis.”

This study was published today in the journal Journal of Geophysical Research: Atmosphere. This research was funded UBC, the Natural Sciences and Engineering Research Council of Canada and the Swiss National Science Foundation.

Contacts and sources:
University of British Columbia

Citation: Impact of global warming on the rise of volcanic plumes and implications for future volcanic aerosol forcing† Authors Thomas J. Aubry, A. Mark Jellinek, Wim Degruyter, Costanza Bonadonna, Valentina Radić, Margot Clyne, Adjoa Quainoo Accepted manuscript online: 16 November 2016Full publication history DOI: 10.1002/2016JD025405

Links:
Comic by the Plainspoken Scientist blog
Blog post from GeoSpace