{"id":4742,"date":"2022-09-11T22:00:00","date_gmt":"2022-09-11T22:00:00","guid":{"rendered":"https:\/\/modernsciences.org\/staging\/4414\/?p=4742"},"modified":"2022-09-01T07:03:10","modified_gmt":"2022-09-01T07:03:10","slug":"whats-going-on-with-the-greenland-ice-sheet-its-losing-ice-faster-than-forecast-and-now-irreversibly-committed-to-at-least-10-inches-of-sea-level-rise","status":"publish","type":"post","link":"https:\/\/modernsciences.org\/staging\/4414\/whats-going-on-with-the-greenland-ice-sheet-its-losing-ice-faster-than-forecast-and-now-irreversibly-committed-to-at-least-10-inches-of-sea-level-rise\/","title":{"rendered":"What\u2019s going on with the Greenland ice sheet? It\u2019s losing ice faster than forecast and now irreversibly committed to at least 10 inches of sea level rise"},"content":{"rendered":"\n
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\n A turbulent melt-river pours a million tons of water a day into a moulin, where it flows down through the ice to ultimately reach the ocean.\n Ted Giffords<\/span><\/span>\n <\/figcaption>\n <\/figure>\n\nAlun Hubbard<\/a>, University of Troms\u00f8<\/a><\/em><\/span>\n\n

I\u2019m standing at the edge of the Greenland ice sheet, mesmerized by a mind-blowing scene of natural destruction. A milewide section of glacier front has fractured and is collapsing into the ocean, calving an immense iceberg.<\/p>\n\n

Seracs, giant columns of ice the height of three-story houses, are being tossed around like dice. And the previously submerged portion of this immense block of glacier ice just breached the ocean \u2013 a frothing maelstrom flinging ice cubes of several tons high into the air. The resulting tsunami inundates all in its path as it radiates from the glacier\u2019s calving front.<\/p>\n\n

Fortunately, I\u2019m watching from a clifftop a couple of miles away. But even here, I can feel the seismic shocks through the ground<\/a>.<\/p>\n\n

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\n A fast-flowing outlet glacier calves a \u2018megaberg\u2019 into Greenland\u2019s Uummannaq Fjord.<\/span>\n Alun Hubbard<\/span><\/span>\n <\/figcaption>\n <\/figure>\n\n

Despite the spectacle, I\u2019m keenly aware that this spells yet more unwelcome news for the world\u2019s low-lying coastlines.<\/p>\n\n

As a field glaciologist<\/a>, I\u2019ve worked on ice sheets for more than 30 years. In that time, I have witnessed some gobsmacking changes. The past few years in particular have been unnerving for the sheer rate and magnitude of change underway. My revered textbooks taught me that ice sheets respond over millennial time scales, but that\u2019s not what we\u2019re seeing today.<\/p>\n\n

A study published<\/a> Aug. 29, 2022, demonstrates \u2013 for the first time \u2013 that Greenland\u2019s ice sheet is now so out of balance with prevailing Arctic climate that it no longer can sustain its current size. It is irreversibly committed to retreat by at least 59,000 square kilometers (22,780 square miles), an area considerably larger than Denmark, Greenland\u2019s protectorate state.<\/p>\n\n

Even if all the greenhouse gas emissions driving global warming ceased today, we find that Greenland\u2019s ice loss under current temperatures will raise global sea level<\/a> by at least 10.8 inches (27.4 centimeters). That\u2019s more than current models forecast, and it\u2019s a highly conservative estimate. If every year were like 2012, when Greenland experienced a heat wave<\/a>, that irreversible commitment to sea level rise would triple. That\u2019s an ominous portent given that these are climate conditions we have already seen, not a hypothetical future scenario.<\/p>\n\n

Our study takes a completely new approach \u2013 it is based on observations and glaciological theory rather than sophisticated numerical models. The current generation of coupled climate and ice sheet models used to forecast future sea level rise fail<\/a> to capture the emerging processes that we see amplifying Greenland\u2019s ice loss.<\/p>\n\n

How Greenland got to this point<\/h2>\n\n

The Greenland ice sheet<\/a> is a massive, frozen reservoir that resembles an inverted pudding bowl. The ice is in constant flux<\/a>, flowing from the interior \u2013 where it is over 1.9 miles (3 kilometers) thick, cold and snowy \u2013 to its edges, where the ice melts or calves bergs.<\/p>\n\n

In all, the ice sheet locks up enough fresh water to raise global sea level<\/a> by 24 feet (7.4 meters).<\/p>\n\n

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