Greenland Will Be Ice-free by the Year 3000 If We Don't Reduce Emissions, Scientists Warn

Scientists have warned that Greenland will be ice-free in the next thousand years unless greenhouse gas emissions are substantially reduced. Using three different climate change scenarios, a team of researchers ran hundreds of simulations to see how the ice would respond in the future.

Their findings showed that if we continue along our current trajectory of warming, 100 percent of Greenland's present-day ice mass will be gone. This could raise sea levels by over seven meters (23 feet).

The Greenland Ice Sheet is a huge mass almost the size of Alaska—but it has started to disintegrate. Subsurface ocean temperatures along its west coast rose by 1.5 C between 1996 and 1998, causing the ice sheet to retreat and thin. Scientists are worried that warming could cause it to collapse—an event predicted to raise sea levels so much that it would submerge a number of major U.S. cities, including San Francisco, Los Angeles and New Orleans.

Scientists are working to understand how Greenland's ice sheet will respond to future warming. The Intergovernmental Panel for Climate Change (IPCC) estimates that if global greenhouse gas emissions continue on their current trajectory, global temperatures will increase by between 2.6 and 4.8 C on pre-industrial levels. If emissions are reduced drastically, this can be reduced to between 0.3 and 1.7 C. A third scenario is emissions peaking at the middle of the century than drop rapidly—if this happens warming of between 1.1 and 2.6 degrees C.

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Using these three climate change scenarios, a team of researchers led by Andy Aschwanden from the University of Alaska Fairbanks Geophysical Institute, developed a model for how Greenland will respond to warming and ran 500 computer simulations to show what could happen over the next 1,000 years. The model took into account atmospheric and ocean conditions as well as ice geometry, flow and thickness.

Their findings, published in Science Advances, showed that "in a thousand years, the Greenland Ice Sheet will look significantly different than today." Under the best case scenario, Greenland will lose between eight and 25 percent of its present-day mass. Under moderate climate change it would lose between 26 and 57 percent, while under the worst case scenario, between 72 and 100 percent will disappear.

greenland ice loss
Figure showing Greenland's predicted ice loss over the next 1,000 years under different climate scenarios. UAF Geophysical Institute

"We project that Greenland will very likely become ice-free within a millennium without substantial reductions in greenhouse gas emissions," they conclude.

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"How Greenland will look in the future—in a couple of hundred years or in 1,000 years—whether there will be Greenland, or at least a Greenland similar to today, it's up to us," Aschwanden said in a statement.

The study comes as researchers find the Canadian permafrost (ground that is permanently frozen) has started to thaw—70 years earlier than predicted. "What we saw was amazing," Vladimir E. Romanovsky, lead author of the study published in Geophysical Research Letters, told Reuters. "It's an indication that the climate is now warmer than at any time in the last 5,000 or more years."

Greenland from space
Greenland from space. NASA/Johnson Space Center
Greenland Will Be Ice-free by the Year 3000 If We Don't Reduce Emissions, Scientists Warn | Tech & Science