Reply To: Climate Crisis: Our Last Chance
Can’t I get away from the bad news.
The release of methane and carbon dioxide from thawing permafrost will accelerate global warming and add up to $70tn (£54tn) to the world’s climate bill, according to the most advanced study yet of the economic consequences of a melting Arctic. It shows how destabilised natural systems will worsen the problem caused by man-made emissions, making it more difficult and expensive to solve.
Permafrost melt is the main concern. Greenhouse gases, which have been frozen below the soil for centuries, have already begun to escape at the current level of 1 degrees Celsius of global heating. So far the impact is small. Ten gigatonnes of CO2 have been released from the ice but this source of emissions will grow rapidly once temperatures rise beyond 1.5C. On the current trajectory of at least 3C of warming by the end of the century, melting permafrost is expected to discharge 280 gigatonnes of carbon dioxide and 3 gigatonnes of methane.
“It’s disheartening that we have this in front of us,” said Dmitry Yumashev of Lancaster University. “Even at 1.5C to 2C, there are impacts and costs. But they are lower so we can limit this. We have the technology and processes, but we are not moving fast enough. We still have a time bomb, but it’s not as large as previously believed,” said Yumashev. But he warned against complacency because even at the low end the damages are huge, the study has a considerable degree of uncertainty and the costs of several other potential tipping points have yet to be calculated.