Climate change is melting even the smallest glaciers, with half of all glaciers around the world predicted to disappear by the end of the century.
The research, published in the journal Science, provides the most accurate projections yet of the future of some 215,000 of the world’s glaciers.
Its authors warn about the importance of reducing greenhouse gas emissions that cause climate change, to limit the melting of glaciers and the consequent rise in sea level.
“I think there is a small glimmer of hope and a positive message in our study, because it tells us that we can make a difference, that actions matter,” said Regine Hock, co-author of the research.
The work focused on studying the direct effect of various global warming scenarios (+1.5°C, +2°C, +3°C and +4°C) on glaciers, to better guide political decisions.
If the temperature increase is only 1.5 °C above pre-industrial levels, the most ambitious goal of the Paris agreement, 49% of the world’s glaciers will disappear.
A loss like that will represent about 26% of the total mass of ice, since the first to melt will be the smallest. In this scenario, the researchers estimate that the sea level will rise by about nine centimetres, an increase to which the melting of the polar caps will add.
“Regions with relatively little ice, such as the Alps, the Caucasus, the Andes, or the western United States, are losing almost all their ice by the end of the century, regardless of the emissions scenario,” said Hock, a professor at the University of Oslo. “These glaciers are pretty much doomed.”
If the temperature rises by 4°C, the worst case scenario, the largest glaciers, such as Alaska, will be hit hardest. 83% of the glaciers would disappear, which is equivalent to 41% of the total mass of its ice, and it would raise the sea level by 15 centimeters.
“It may not sound like a lot, 9 cm to 15 cm,” but these levels are “a huge cause for concern,” Hock said, because the higher they get, they will cause more flooding in storm events and cause “much more damage.”
This is already happening, as the sea level has been rising by around 3mm per year. At the moment, the world is heading towards a warming of 2.7°C, which would lead to a near total thaw in Central Europe, western Canada and the United States, and even in New Zealand.
These projections, more alarming than those currently held by the UN climate experts (IPCC), were possible thanks to the obtaining of new data on the mass variations of each glacier in the world during the last decades.