Greenland's ice is melting at the rate scientists thought would be our worst-case scenario in 2070

nuuk greenland ice melt

Sandy Virgo/Associated Press

Small pieces of ice float in the water off the shore in Nuuk, Greenland on June 13, 2019.

Greenland is known for its glaciers, but in the past month, the island has shed ice and taken on fire.

Scientists didn't expect to see Greenland melt at this rate for another 50 years: By the last week of July, the melting had reached levels that climate models projected for 2070 in the most pessimistic scenario.Advertisement

The dramatic melt suggests that Greenland's ice sheet is approaching a tipping point that could set it on an irreversible course towards disappearing entirely. If that happens, catastrophic sea-level rise would swallow coastal cities across the globe. As ice melt continues to outpace scientists' expectations, some fear that could happen more quickly than they thought.

55 billion tons of water in 5 days

greenland ice melt

NASA via Associated Press

A satellite image shows melt-water ponding on the surface of the ice sheet in northwest Greenland, near the sheet's edge, on July 30, 2019.

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The Arctic's melting season starts each year in June and ends in August, with peak melting in July. However, the scale of ice loss in Greenland this year was extraordinary. From July 30 to August 3, melting occurred across 90% of the continent's surface, dumping 55 billion tons of water over 5 days. That's enough to cover Florida in almost 5 inches of water.

This extreme melting came during the hottest month ever recorded, as an intense heat wave washed over Europe then wafted over to Greenland. Low-elevation ice began to melt and form pools across the ice sheet, and those pools' dark colors absorbed more sunlight, which further melted the glacier around them and exposed more ice to hot air.Advertisement

greenland ice melt

Caspar Haarloev from "Into the Ice" documentary via Reuters

Ice melts during a heatwave in Kangerlussuaq, Greenland on August 1, 2019.

Similarly above-average melting was observed in Switzerland - glaciers there lost 800 million tons of ice during the heat waves of June and July. Alaska also saw record sea-ice melt in July.

All that melting exposes more permafrost: frozen soil that releases powerful greenhouse gases when it thaws. That's happening faster than scientists predicted. The release of those gases leads the planet to warm even more, which accelerates more ice melt.Advertisement

Last month was an anomaly for Greenland, but it could be the new normal by 2070 if humans don't curb greenhouse-gas emissions, according to climate models simulated by Xavier Fettweis, a climate researcher at the University of Liège in Belgium.

"By mid to end of the century is when we should be seeing these melt levels - not right now," Ruth Mottram, a climate scientist at the Danish Meteorological Institute, told Inside Climate News. "[The models] are clearly not able to capture some of these important processes."

Melting ice in Greenland raises sea levels

Greenland's ice melt has already raised sea levels more than 0.5 inches since 1972. Half of that occurred just in the last eight years, according to a study published in April. Advertisement

At this rate, the entire Greenland ice sheet could melt within 1,000 years, causing up to 23 feet of sea level rise.

But Mottram isn't so sure about that projected timeline.Advertisement

"Somewhere between 1.5 and 2 degrees, there's a tipping point after which it will no longer be possible to maintain the Greenland Ice Sheet," she told Inside Climate News. "What we don't have a handle on is how quickly the Greenland Ice Sheet will be lost."

That makes it difficult for the ice sheet to regenerate what it's losing.Advertisement

Unprecedented fires have also burned across the Arctic

greenland wildfire

Joshua Stevens/NASA Earth Observatory

Satellites detected the infrared signal of a wildfire near Sisimiut, Greenland on July 10, 2019.

The warm, dry weather that caused the ice to melt also set the stage for wildfires in Greenland.

Satellites first detected a wildfire near Sisimiut area on July 10. Temperatures in the region at the time approached 68 degrees Fahrenheit (20 degrees Celsius); the normal daily high is 50 degrees (10 degrees Celsius).Advertisement

The fires may have been started by a hiker using an outdoor oven.

This was the first fire of its size since another large one in the same area surprised scientists in August 2017. That fire blazed for two weeks.

alaska fires

Lauren Dauphin/NASA Earth Observatory

NASA's Aqua satellite captured thick wildfire smoke swirling over Alaska on July 8, 2019.

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CAMS tracked over 100 "intense and long-lived" wildfires in the Arctic Circle over six weeks in June and July. Those fires spread farther, burned more intensely, and lasted longer than normal.

Fires in Alaska and Siberia also deposited soot on Greenland's ice sheet, which darkened the surface and caused it to absorb more heat, which leads to faster melting.Advertisement

"It is unusual to see fires of this scale and duration at such high latitudes in June," Mark Parrington, a CAMS wildfire expert, said in a release. "But temperatures in the Arctic have been increasing at a much faster rate than the global average, and warmer conditions encourage fires to grow and persist once they have been ignited."

Arctic regions are especially sensitive to climate change

The Arctic is warming almost twice as quickly as the global average. Advertisement

On the other end of the globe, Antarctica's melt is also accelerating. The continent has lost 252 billion tons of ice per year in the last decade. That's just a hair behind Greenland, which is losing an average 286 billion tons per year.

penguin Antarctica

MARK RALSTON/AFP/Getty Images

An Adelie penguin colony beside the frozen Ross Sea area near McMurdo Station, Antarctica on November 11, 2016.

Together, Greenland and Antarctica hold more than 99% of the world's fresh water in their ice sheets, according to the National Snow and Ice Data Center. If both were to melt entirely, the state of Florida would disappear.Advertisement

According to a map from National Geographic, cities like Amsterdam, Netherlands; Stockholm, Sweden; Buenos Aires, Argentina; Dakar, Senegal; and Cancun, Mexico (to name just a few) would also vanish.

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