New research has warned that the release of undersea reservoirs of gases has superheated the planet historically, contributing to the end of the ice age.
The new findings challenge a scientific model which assumed that ocean water alone was responsible for regulating the amount of carbon dioxide and methane in the atmosphere during glacial cycles.
Instead, geological processes have been a dramatic contributor to the carbon cycle, including trapping greenhouse gases that would otherwise saturate the atmosphere.
Published in the journal Environmental Research Letters, the scientists at the University of Southern California’s study has warned that if these undersea reservoirs are disturbed again it would compound man-made climate change.
In this video from the National Academy of Sciences, a deep-sea reservoir near Taiwan spews carbon dioxide. Scientists fear such gas releases superheated the planet in the past, and warn that we need to be aware of their potential contribution in the future. Story to follow… pic.twitter.com/wWc6rYsQkw
— Sky News Tech (@SkyNewsTech) February 14, 2019
“We’re using the past as a way to anticipate the future,” said Lowell Stott, professor of earth sciences at USC and lead author of the study.
“We know there are vast reservoirs of carbon gas at the bottom of the oceans. We know when they were disrupted during the Pleistocene it warmed the planet.
“We have to know if these carbon reservoirs could be destabilised again. It’s a wild card for which we need to account,” Professor Stott said.
Carbon dioxide and methane accumulate underwater as a result of volcanic activity which releases heat and gases that congeal within an icy slurry encapsulating the reservoirs.
These reservoirs are usually quite stable, but warming oceans have made them vulnerable.
One giant reservoir discovered off the coast of Taiwan lies about 4,000 feet deep in the ocean, and similar reservoirs have been found holding carbon gas off the coast of Okinawa, in the Aegean Sea, in the Gulf of California and off the west coast of Canada.
“The grand challenge is we don’t have estimates of the size of these or which ones are particularly vulnerable to destabilisation,” Professor Stott said. “It’s something that needs to be determined.”
The problem with the reservoirs is that the amount of carbon they hold hasn’t been included within the marine carbon budget, the way global society measures emissions targets.
“Even if only a small percentage of the unsampled hydrothermal systems contain separate gas or liquid carbon dioxide phases, it could change the global marine carbon budget substantially,” warns the study.
Professor Stott added: “Discoveries of accumulations of liquid, hydrate and gaseous carbon dioxide in the ocean has not been accounted for because we didn’t know these reservoirs existed until recently, and we didn’t know they affected global change in a significant way.
“This study shows that we’ve been missing a critical component of the marine carbon budget. It shows these geologic reservoirs can release large amounts of carbon from the oceans.”