Researchers have drawn up a list of climate ‘tipping points’ we are in danger of tripping this century. Even a small amount of human induced climate change could push these vital parts of the planet over the edge, says Tim Lenton of the University of East Anglia.
The really bad news: Lenton thinks some of the tipping points are under ten years from happening.
“Society must not be lulled into a false sense of security by smooth projections of global change,” he says (press release). “Our findings suggest that a variety of tipping elements could reach their critical point within this century under human-induced climate change. The greatest threats are tipping of the Arctic sea-ice and the Greenland ice sheet, and at least five other elements could surprise us by exhibiting a nearby tipping point.”
In a new paper in PNAS Lenton and his colleagues coin the term ‘tipping element’ for “large-scale components of the Earth system that may pass a tipping point”. Below the fold you can find the full list and media coverage links.
The nine tipping elements and the time it will take them to undergo a major transition:
Melting of Arctic sea-ice (approx 10 years)
Decay of the Greenland ice sheet (more than 300 years)
Collapse of the West Antarctic ice sheet (more than 300 years)
Collapse of the Atlantic thermohaline circulation (approx 100 years)
Increase in the El Nino Southern Oscillation (approx 100 years)
Collapse of the Indian summer monsoon (approx 1 year)
Greening of the Sahara/Sahel and disruption of the West African monsoon (approx 10 years)
Dieback of the Amazon rainforest (approx 50 years)
Dieback of the Boreal Forest (approx 50 years)
Graphic PDF from The Guardian
Coverage
Climate change ‘tipping point’ within 100 years – The Daily Telegraph
Climate set for ‘sudden shifts’ – BBC
Nine zones are identified as key climate ‘tipping points’ – The Times
Global meltdown: scientists isolate areas most at risk of climate change – The Guardian
Scientists fear climate change could bring abrupt changes – Canwest News
UPDATE: It’s just been pointed out to me that Lenton’s ‘tipping elements’ actually first appeared in a Nature Reports Climate Change commentary back in November (text / PDF; subscription required).
Image: Arctic sunset / NOAA Climate Program Office, NABOS 2006 Expedition