A team of scientists from the Universities of Leeds and Edinburgh, and Imperial College London, studied the ice sheets in Antarctica and Greenland and made a disturbing discovery. Utilizing satellite data and other models to detail for the first time the extraordinary total impact of the climate crisis on various bodies of ice, they've determined that between 1994 and 2017 the Earth lost 28 trillion tons of ice and the rate is accelerating rapidly. In total, 60% of the loss comes from the northern hemisphere.
While the melting of floating sea ice does not directly contribute to sea level rise, the huge volumes of grounded ice in Antarctica and Greenland which have melted, as well as that from glaciers, have already contributed as much as 3.5cm to global sea levels between 1994 and 2017.
Dr Isobel Lawrence, a research fellow at the University of Leeds and a co-author of the study, “The thing which is most cause for concern is the [melt] rate we’ve calculated is accelerating. In the two decades since the 1990s, we’ve seen this estimate go up from 0.8 to 1.2 trillion tonnes of ice a year, so that’s a 57 per cent increase in one decade.
“If that continues, which it’s expected to because emissions are continuing to rise, then all of this melt is going to continue to accelerate.
“That has consequences for sea level rise. Greenland and Antarctic ice sheets and glaciers are grounded ice, so their melt contributes to sea level rise. The melt of sea ice and ice shelves doesn’t contribute to sea level rise because they float on water, and about 54 per cent of ice is floating and 46 per cent is grounded, so it means roughly half of the losses we’ve estimated are directly adding to sea level rise.”
Alongside the rising sea levels, the melting of such extensive masses of ice pose other problems. All the ice stored in glaciers and in the ice sheets of Antarctica and Greenland are composed of freshwater, and when they melt and drain into the oceans, the huge volumes of freshwater then change the salinity of the seas.
Dr Lawrence said, “In the Southern Ocean and the Arctic Oceans we’ve seen changes in circulation as a result of freshwater impact. What we don’t know yet is the result of that on the rest of the world, because global ocean circulation is all linked up.
“If this freshwater input causes a change in global ocean circulation – which some models have shown – then it could have consequences for the climate globally over a longer time scale.”
The research has been published as a preprint in open access journal The Cryosphere and is yet to be peer-reviewed.