Having two caps of a permanent ice in the Arctic and Antarctica is the very precondition for the planet to stay in a state that has enabled us to develop civilizations as we know it. Whether it’s a small glacier or whether we’re talking about Greenland, they all add together to this fantastic capacity of cooling the planet.

Icecaps and glaciers are reflecting back 90 to 95% of incoming heat from the sun. When these ice sheets start melting, you can come to a point where the ice sheets tip over from being self-cooling to becoming self-warming and that is the most dramatic tipping point in their system..in the current climate, Greenland is already beyond its threshold where it’s now losing 10,000 cubic metres of ice per second. That loss rate will only continue as the climate heats up.

So is Greenland lost? Evidently, it is.

The drama here is that one characteristic of tipping points is that once you press the on button you cannot stop it. It takes over. It’s too late. It’s not like you could say, ‘Oops now I realise I didn’t want to melt the Greenland ice sheet. Let’s back off.’ Then it’s too late. The important point to make here is that everything in the Earth system is connected. When one part of the climate system crosses its tipping point, then that might make it more likely for other parts of the system to also cross their critical thresholds. So you can think of this in terms of dominoes. If you tip one of them over, then this might lead to cascading effect. – Prof. Jason Box in Breaking Boundaries: The Science of our Planet.