"Runaway greenhouse effect" is what could happen if the methane deposits in the Arctic Siberian tundra are released to the atmosphere. See [1] for more informat

"Runaway greenhouse effect" is what could happen if the methane deposits in the Arctic Siberian tundra are released to the atmosphere. See [1] for more information. [1] https://en.wikipedia.org/wiki/Arctic_methane_emissions https://en.wikipedia.org/wiki/Arctic_methane_emissions Edit: if it's not obvious, "runaway effect" is another term for "positive feedback loop". The first paragraph of the linked article reads: > Arctic methane release is the release of methane from seas and soils in permafrost regions of the Arctic, due to deglaciation. While a long-term natural process, it may be exacerbated by global warming. This results in a positive feedback effect, as methane is itself a powerful greenhouse gas.