News about the death of the Greenland Ice Sheet is greatly exaggerated. What the new paper shows is an observed increase in solid ice discharge into the ocean, which has been at a higher rate than before during the past 15 years. The authors basically say: if this continues, ...
...then the Greenland Ice Sheet will continue to lose mass.
But due to that, the ice front retreats from the ocean, as nicely shown e.g. in Andy Aschwanden's detailed simulations:
And when the ice loses contact with the ocean, the ice discharge stops.
But due to that, the ice front retreats from the ocean, as nicely shown e.g. in Andy Aschwanden's detailed simulations:
And when the ice loses contact with the ocean, the ice discharge stops.
The tipping point for losing the Greenland Ice Sheet altogether therefore depends on surface melt permanently exceeding snowfall and does not involve solid ice discharge. Whether this real tipping point of Greenland has been crossed, we do not know.
Thus, Greenland ice loss is a real concern - already today it contributes a lot to sea level rise. And Greenland does have a tipping point where the ice sheet becomes doomed to total loss. But the new paper by King et al. does not say anything about whether this has been crossed.
And here’s Mike Mann posting comments by glaciologist Richard Alley, explaining the same thing. I learned a lot about ice sheets from Richard when we were both part of the Panel on Abrupt Climate Change!
Here are my annotations to the CNN story on the Greenland paper: via.hypothes.is/https://www.cn…
