Paris, Nov 28 (AFP/APP): Loading the atmosphere with five million tonnes of CO2 every hour has pushed Earth dangerously close to a no-return threshold, beyond which lies an unlivable hothouse world, top climate scientists have warned. There are 15 known tipping points in the planet’s complex climate system, and nine of them — including permafrost, the Amazon rainforest, the Greenland icesheet, Arctic sea ice, and the Atlantic Ocean’s circulation — are alarmingly “on the move”, they reported in the journal Nature. Locked inside the tundra of Russia, Alaska and Canada, for example, is twice as much CO2 and methane as there is already in the atmosphere. If humanity cannot manage its own carbon pollution, what will we do if Earth turns from sink to source, adding even more? AFP spoke to two of the authors — Tim Lenton, director of the Global Systems Institute at the University of Exeter, and Johan Rockstrom, director of the Potsdam Institute for Climate Impact Research. Losing control: Q. How has scientific understanding of tipping points changed over the last decade or two ROCKSTROM: Today we are reaching a point of unequivocal scientific evidence that these tipping elements are real. The Earth system is an … Continue reading Climate Change ‘Tipping Points’ too Close for Comfort