Climate’s scientists fear tipping points

Climate’s scientists fear tipping points

PARIS: Leaders may be going into the UN climate summit in Glasgow with the do-or-die goal of limiting global warming at 1.5 degrees Celsius, but breaching that cap is not what keeps scientists awake at night. The real disaster scenario begins with the triggering of invisible climate tripwires known as tipping points. “Climate tipping points are a game-changing risk – an existential threat – and we need to do everything within our power to avoid them,” said Tim Lenton, director of the Global Systems Institute at the University of Exeter.

What’s a tipping point?

Anyone who has leaned back in a chair balancing on two legs knows there is a threshold beyond which you irrevocably crash to the floor. That portal between two stable states – in this case, an upright versus a fallen-over chair – is a tipping point, and Earth’s complex, interlocking climate system is full of them. These temperature thresholds have potentially widespread impacts. If temperatures rise enough to melt the ice sheets atop Greenland and West Antarctica, it could lift oceans more than a dozen meters.

The Amazon tropical forest, upon which we depend to soak up carbon pollution, could turn into savannah. Or shallow subsoil known as permafrost