‘Extraordinary thinning’ of ice sheets revealed deep inside Antarctica:
New research shows affected areas are losing ice five times faster than in the 1990s, with more than 100m of thickness gone in some places
As with everything to do with AGW, it is the speed of the change that is the greatest concern, as this pattern lends itself to domino scenarios where you hit various tipping points and multiple negative (in terms of human and natural eco systems abilities to adapt) effects start to take place in rapid succession.Ice losses are rapidly spreading deep into the interior of the Antarctic, new analysis of satellite data shows.
The warming of the Southern Ocean is resulting in glaciers sliding into the sea increasingly rapidly, with ice now being lost five times faster than in the 1990s. The West Antarctic ice sheet was stable in 1992 but up to a quarter of its expanse is now thinning. More than 100 metres of ice thickness has been lost in the worst-hit places.
A complete loss of the West Antarctic ice sheet would drive global sea levels up by about five metres, drowning coastal cities around the world. The current losses are doubling every decade, the scientists said, and sea level rise are now running at the extreme end of projections made just a few years ago.
The research, published in the journal Geophysical Research Letters, compared 800m satellite measurements of ice sheet height from 1992 to 2017 with weather information. This distinguished short-term changes owing to varying snowfall from long-term changes owing to climate.
“From a standing start in the 1990s, thinning has spread inland progressively over the past 25 years – that is rapid in glaciological terms,” said Prof Andy Shepherd, of Leeds University in the UK, who led the study. “The speed of drawing down ice from an ice sheet used to be spoken of in geological timescales, but that has now been replaced by people’s lifetimes.”