Around 100 million years ago, there was an enormous explosion of methane that made its way up into Earth’s atmosphere, which, along with a few powerful volcanic eruptions, helped bring about a profoundly hot climate. Now, it appears that researchers wandering through the Arctic have found the scars of this methane ejection, and their work implies that a similarly devastating event could happen any day now.
Writing in the Bulletin of the Geological Society of America, the team – led by the University of Calgary – describe a series of bubble-like bumps on Canada’s Ellef Ringnes Island. Based on the surrounding geological layers, it appears that these scars all emerged at the same time, suggesting that there was an enormous release of methane back then.
“The discovery of 137 Early Cretaceous carbonate deposits [in the] Canadian Arctic Archipelago, demonstrates the presence of an extensive field of methane seeps that occur over a >10,000 km2 area,” the team write in their study.
Methane breaks down in the atmosphere far quicker than carbon dioxide, but it is up to 36 times more potent as a greenhouse gas. Whenever it’s released en masse into the atmosphere, it triggers a rapid warming event that can led to several regional extinction events.
The most famous example of this took place 55 million years ago, when a suspected methane explosion led to a sudden warming spike, which ultimately triggered a series of die-offs and brought about a new geological epoch.
Methane is already escaping out of the seafloor. Seaphotoart/Shuterstock
This latest study suggests that a methane explosion took place around the time of the Cretaceous Hothouse period, when huge volcanic carbon dioxide effusions bumped temperatures up to 9°C (16.2°F) higher than they are today.
This methane was likely unleashed from frozen deposits buried beneath the seafloor, a geological feature that is widespread today. A truly colossal cache of frozen methane was found off the western coast of Central America just this year, and the Siberian Arctic’s permafrost is riddled with the stuff.