What will happen to the Greenland ice sheet if we miss our global warming targets
What will happen to the Greenland ice sheet if we miss our global warming targets
The ice will survive if temperatures are soon brought back down – new study.
The results are fascinating. If temperatures peak at 2°C or so, and remain there, then the models – as expected – predict substantial ice sheet collapse after several thousands of years.
However, things change if warming is seriously mitigated post-2100. In those models, inertia in the ice sheet’s response – a bit like the time it takes for a ripple to settle down as it passes across a pond – means that an overshoot is at least partly reversible as long as temperatures are quickly brought back down.
The paper is here, and says:
Our results show that the maximum GMT and the time span of overshooting given GMT targets are critical in determining GrIS stability. We find a threshold GMT between 1.7 °C and 2.3 °C above preindustrial levels for an abrupt ice-sheet loss.
There's no way we will stop in time for +2°C.
That's a human decision, and one that's not yet done. I'll be doing every bit I can for every tenth of a degree.
God I love this comment. Well said.
It'll melt.
Seems like a key new paper, but not surprising to me. It takes a long time to melt ice kilometers thick, so it's the integral of warming that counts. However once its altitude drops below a certain level, the snow on the top becomes rain, and it can only go down.
threshold GMT between 1.7 °C and 2.3 °C
could be not far away now -and note also (abstract):
even temporarily overshooting the temperature threshold, without a transition to a new ice-sheet state, still leads to a peak in SLR of up to several metres