Methane spike sparks premature concern

The rise led to fears that the melting of Siberian permafrost had begun spiralling out of control. But the paper reported data up to only April 2008 and more recent figures show methane levels have stabilised again.

Methane is the second most important greenhouse gas and like carbon dioxide it is monitored at sites around the world. CO₂ has increased steadily over the years, but methane levels have varied, responding to a poo