At a Glance

About36 percent of the ice still stored in glaciers todaywill melt because of past greenhouse gas emissions.Losing a third of ice also means that sea levels will rise by more than 4 inches.To keep current amounts of glacial ice, the average global temperature would need to drop to pre-industrial levels.

A third of all glaciers, including those that adorn many U.S. national parks, will be obliterated thiscentury even if global warming was halted today, a new study says.

Using glacier models and datafrom, researchers fromGermany's University of Bremen and Austria's Innsbruck University studied mountain glaciers outside Antarctica and Greenland and found that the "further in the current century — even if all emissions were stopped now," according to a press release.

Ben Marzeion of the University of Bremen and leadauthor of the study published last week in Nature Climate Change said that aboutstill stored in glaciers todaywill melt because of past greenhouse gas emissions.

"That meansmore than a third of the glacier ice that still exists today in mountain glaciers can no longer be saved even with the most ambitious measures," Marzeion said.

Losing a third of ice stored in glaciers also means that sea levels will rise by more than 4 inches, the authors note.

"Melting glaciers have a huge influence on the development of sea level rise. In our calculations, we took into account all glaciers worldwide — without the Antarctic and Greenland ice sheets and peripheral glaciers — and modeled them in various climate scenarios," Georg Kaser of the Institute of Atmospheric and Cryospheric Sciences at the University of Innsbruck said.

The authors explain in the studythat it can take millennia for glaciers to respondto climate conditions. In other words,there is a gap between the rapid rise in temperatures over the past centuryand the time it will take for the glaciers to catch up and melt as a result.

They also point out that topreservethe amount of glacial ice that currently exists, the average global temperature would have to drop to pre-industrial levels, something the authors say "is obviously not possible."

(MORE:)

To illustrate the effects of carbon emissions on glaciers, the researcherscalculated that every kilogram (2 pounds) of CO2 that is emittedtoday will result in 15 kilograms (33 pounds) of glacier melt in the long term.

"Calculated on the basis of an average car newly registered in Germany in 2016, this means that one kilogram (2 pounds) of glacier ice is lost every five hundred meters (0.3 miles) by car," Marzeion said.

Kaser said thegreenhouse gas emissions from the past have "already triggered changes that can no longer be stopped," but noted that keeping the average mean temperatures to below 1.5 degrees Celcius above pre-Industrial levels, a marker ofthe Paris Climate Accord, will make a significant difference in preserving the world's glaciers and preventing further sea level rise.

Gerard Roeof theUniversity of Washington was the leadauthor of as “categorical evidence” of human-caused climate change. In response to this latest study, Roe told Carbon Brief that it's further proof that "we really are on course to obliterate many of these mountain landscapes.”