This weekend, @JpvanYpersele and I commented for @FRANCE24 on new article by @Michalea_King. We (independently) said the same: excellent and very important study, but claim about ‘point-of-no-return’ being crossed for Greenland ice sheet may be somewhat misleading. A thread [1/9]

At present, the ice that discharges into the ocean (calving) and frontal melting are indeed too large to be compensated by the mass gain at the surface. So even if temperatures would stabilize at present-day levels, the ice sheet would lose mass for quite some time. [2/9]

But one needs to be careful when using (extrapolating) present-day observations and trends to make future projections. An important question here is: how will the total amount of ice discharge (calving) and frontal melt evolve in the future? [3/9]

As glaciers retreat, the calving and frontal melt will likely increase at first (positive correlation retreat and discharge shown in study). But eventually, as Greenland’s glaciers have less contact with the ocean, the total discharge and frontal melt will decrease. [4/9]

See for instance this very nice study from a few years ago: https://tc.copernicus.org/articles/9/1039/2015/. So eventually, if temperatures could stabilize at a given level and calving decreases, a new equilibrium may be reached [5/9]

Also, using the term ‘point-of-no-return’ may send a wrong message: it gives the false impression that the loss of the Greenland ice sheet is irreversible and that the ice sheet will “anyway be lost”. [6/9]

But this is not true: our present-day actions will have a large influence on the future evolution of the Greenland ice sheet [7/9]

In a nutshell: amazing and very important work, but the message out in the media (which authors often don't have full control of) can be seen as somewhat misleading. The situation for the ice sheet is really bad, but it’s (luckily) not yet a ‘lost cause’ [8/9]

The study: https://www.nature.com/articles/s43247-020-0001-2
Reuters article: https://www.reuters.com/article/us-climate-change-arctic-idUSKCN25A2X3
An interesting discussion on this (in French), with @JpvanYpersele and @FrankPattyn: https://www.rtbf.be/info/monde/detail_rechauffement-climatique-la-fonte-de-la-calotte-glaciere-du-groenland-aurait-atteint-le-point-de-non-retour-vrai-ou-faux?id=10562919&utm_source=rtbfinfo&utm_campaign=social_share&utm_medium=twitter_share [9/9]