The largest natural source of greenhouse gas is in tropical forests — but a team of researchers might have found a close second.
Nitrous oxide, also known as laughing gas, naturally occurs in peatland permafrost. It's also a greenhouse gas almost 300 times more potent than carbon dioxide.
When the ground is frozen, nitrous oxide isn't really a problem because the gas isn't active. But now the Arctic is thawing more rapidly, the team fears those "hot spots" are inching dangerously close to release.