The collapse of a major system of ocean currents, the meltdown of major ice sheets or the dieback of the Amazon rainforest are all examples of negative climate tipping points. These are the big risks associated with a changing climate, where harmful change becomes self-propelling. Each could cause environmental disasters affecting hundreds of millions of people.
The prospect of such irreversible and massively damaging outcomes is looming ever closer, as we are set to exceed 1.5°C global warming. Every year and every 0.1°C above this threshold increases the risk of crossing negative climate tipping points. To avert them, climate action must accelerate spectacularly. We need to decarbonise the global economy five times faster than the current rate to have reasonable odds of limiting warming well below 2°C.
