THE ominous phrase “tipping point” entered the vocabulary of climate science this year, sounding a warning that global warming may soon spiral out of control.
The permafrost beneath the west Siberian peatlands is thawing, creating giant lakes and swelling rivers. More worryingly, the melting of the bogs – which cover an area the size of France and Germany combined – could unleash billions of tonnes of methane. This greenhouse gas is 20 times more potent than carbon dioxide, so the event has the potential to accelerate global warming.
Meanwhile, higher air and sea temperatures dramatically reduced the extent of sea ice in…
