Science Alert  September 2, 2020 A bubble of methane gas, swelling beneath Siberia’s melting permafrost for who knows how long, has burst open to form an impressive 50-metre-deep (164-foot-deep) crater throwing chunks of ice and rock hundreds of metres away from the epicentre. It is not clear when the hole formed, or if climate change played a role. The giant holes are thought to result from the sudden collapse of hills, or swellings of tundra, which themselves form when melting permafrost causes a build-up of methane beneath the surface. Methane is 84 times more potent as a greenhouse gas than […]