THE Arctic tundra lets out a huge icy burp every year, explaining a long-standing mystery about why atmospheric methane levels spike at the start of every winter.
Torben Christensen at Lund University in Sweden and colleagues reckon the freezing of the ground squeezes the soil like a sponge so that it belches out huge amounts of the gas.
The team measured the flow of methane coming from the ground in north-eastern Greenland at the onset of winter. They found that levels of the gas rose at the highest rate ever recorded in the Arctic tundra (Nature, vol 456, p…
