Five climate thresholds may have already been crossed

Climate change is not just gradual change.

There are also threshold effects in the climate, or tipping points, where nature can go from one state to another in a short time due to warming.

And now there are not just nine but 16 such, and several are closer than previously thought.

The researchers at the Stockholm Resilience Center draw this conclusion after going through over 200 scientific reports on threshold effects over the past 15 years.

- Our conclusion is that we are already in the danger zone for certain tipping points, says David Armstrong McKay at the University of Exeter and who is the study's lead author to SVT.

May already be here

Five of them can happen already now with the warming so far of around 1.1 degrees, the researchers warn.

There is the melting of the ice in Greenland and in West Antarctica, there is melting permafrost on the tundra, changing ocean currents in the Labrador Sea off Greenland, and coral death due to warmer seas.

- The two that I find very worrying are the melting of the ice caps in Greenland and West Antarctica, which not only have a major impact on the climate but can also lead to a major rise in sea levels.

And partly the thawing permafrost, which can cause methane emissions that accelerate the warming even further, says Ingo Fetzer, researcher at SRC.

Every tenth increases the risk

In Paris 2015, the countries of the world agreed to try to keep warming below 2 degrees with an aim of 1.5.

Even more threshold effects can occur if the temperature increase exceeds 1.5 degrees.

That worries the researchers.

- Yes, of course.

Because we will almost certainly pass one and a half degrees of warming even if emissions decrease rapidly.

And at that level we see that some of the threshold effects become likely.

But even if we go above 1.5 degrees, it is worth reducing emissions as much as possible to prevent other tipping points from becoming likely, says David Armstrong McKay.