This chart from a paper in Science Advances shows how burning different amounts of the world’s remaining fossil fuel reserves could affect Antarctic ice. The abbreviation GtC stands for gigatons (billions of tons) of carbon. Credit Ken Caldeira and Ricarda Winkelmann
Posted: 11 Sep 2015 01:41 PM PDT
New work demonstrates that the planet’s remaining fossil fuel resources would be sufficient to melt nearly all of Antarctica if burned, leading to a 50- or 60-meter (160 to 200 foot) rise in sea level. Because so many major cities are at or near sea level, this would put many highly populated areas where more than a billion people live under water, including New York City and Washington, D.C…..
Ricarda Winkelmann, Anders Levermann, Andy Ridgwell, and Ken Caldeira. Combustion of available fossil fuel resources sufficient to eliminate the Antarctic Ice Sheet. Science Advances, 2015 DOI: 10.1126/sciadv.1500589
Calving ice near Paradise Harbor in Antarctica in Jan. 2015. The continent’s ice sheet and the rest of the world’s land ice would melt if all the world’s fossil fuels were burned, a new climate study found. Credit Ralph Lee Hopkins/National Geographic Creative
By JUSTIN GILLIS SEPT. 11, 2015 NY Times
Burning all the world’s deposits of coal, oil and natural gas would raise the temperature enough to melt the entire ice sheet covering Antarctica, driving the level of the sea up by more than 160 feet, scientists reported Friday. In a major surprise to the scientists, they found that half the melting could occur in as little as a thousand years, causing the ocean to rise by something on the order of a foot per decade, roughly 10 times the rate at which it is rising now.
Such a pace would almost certainly throw human society into chaos, forcing a rapid retreat from the world’s coastal cities. The rest of the earth’s land ice would melt along with Antarctica, and warming ocean waters would expand, so that the total rise of the sea would likely exceed 200 feet, the scientists said. “To be blunt: If we burn it all, we melt it all,” said Ricarda Winkelmann, a researcher at the Potsdam Institute for Climate Impact Research in Germany and the lead author of a paper published Friday in the journal Science Advances.
A sea level rise of 200 feet would put almost all of Florida, much of Louisiana and Texas, the entire East Coast of the United States, large parts of Britain, much of the European Plain, and huge parts of coastal Asia under water. The cities lost would include Miami, New Orleans, Houston, Washington, New York, Amsterdam, Stockholm, London, Paris, Berlin, Venice, Buenos Aires, Beijing, Shanghai, Sydney, Rome and Tokyo. Nobody alive today, nor even their grandchildren, would live to see such a calamity unfold, given the time the melting would take. Yet the new study gives a sense of the risks that future generations face if emissions of greenhouse gases are not brought under control.
“This is humanity as a geologic force,” said Ken Caldeira, a researcher at the Carnegie Institution for Science in Stanford, Calif., and another author of the paper. “We’re not a subtle influence on the climate system – we are really hitting it with a hammer.” Climate scientists have long assumed that countries would recognize the dangers of continuing to dig up and burn the world’s fossil fuels. Yet they have been saying that for 30 years, and political efforts in that time to limit the burning have been ineffectual. With a major push from President Obama, the nations of the world will convene in Paris in December in another attempt to reach an ambitious deal for reducing emissions. Yet Mr. Obama faces fierce opposition from the Republican Party in putting limits into effect in the United States, which uses more fossil fuels per person than any other large country. The long-running political gridlock has prompted scientists to start thinking about worst-case scenarios. And recently, major advances have been made in the computerized analysis of the huge ice sheets covering Antarctica and Greenland. The researchers involved in Friday’s paper decided to use one of these ice-sheet models to attempt the most detailed analysis yet of the potential consequences of burning all fossil fuels.
As the first of its kind, the paper is likely to undergo intense scientific scrutiny. In certain ways, the findings are reassuring. They offer no reason, for instance, to revise the sea-level forecast for the coming century. A United Nations panel has said that the rise of the sea would not likely exceed three feet in that period, and would probably be less. While some island nations may be wiped out by a rise of that magnitude, experts believe most major cities could be protected from it, though at a likely cost in the trillions of dollars. The ice sheets respond slowly enough to changes in the climate that it simply takes longer than a century for large-scale melting to begin. But from that point, the paper found, about half the Antarctic ice sheet would melt or fall into the sea in the first thousand years. “I didn’t expect it would go so fast,” Dr. Caldeira said. “To melt all of Antarctica, I thought it would take something like 10,000 years.”
Ricarda Winkelmann of the Potsdam Institute for Climate Impact Research in Antarctica. “If we burn it all, we melt it all,” she said. Credit Maria Martin/Potsdam Institute for Climate Impact Research
| A new analysis of Antarctica’s vast ice sheet in a world heated by unabated greenhouse gas emissions from fossil fuel burning comes to a stark, if unsurprising, conclusion: Burn it all, lose it all.
The paper, published online this afternoon in the journal Science Advances, is titled, “Combustion of available fossil fuel resources sufficient to eliminate the Antarctic Ice Sheet.” The modeling study is far more a thought experiment than a prediction, given that, even in China, there is every indication that the world’s coal, particularly, will not all be exploited. But it is another reminder that energy choices made today will have repercussions for thousands of years to come, as David Archer laid out so well in “The Long Thaw” and as earlier research on Antarctic ice sheets has concluded. The authors of the study — Ricarda Winkelmann and Anders Levermann from the Potsdam Institute for Climate Impact Research, Ken Caldeira of the Carnegie Institution for Science and Andy Ridgwell of the University of Bristol — find that the loss of the entire Antarctic ice sheet would take millenniums, but up to 100 feet of sea level rise could result within 1,000 years, with the rate of the rise beginning to increase a century or two from now. That finding meshes with the 2014 paper on the “collapse” of the West Antarctic Ice Sheet. Earlier today, I had a video chat about the study and its implications with three of the authors — Winkelmann, Levermann and Caldeira. You can watch it or read a few excerpts below: Justin Gillis has written a news article putting the paper in context with other recent research on Antarctic dynamics and sea level, as well as with policy debates about the current value of fossil fuels against the momentous costs that could attend greatly expanded use:
In interviews, scientists said that such long-term risks raise profound moral questions for people of today.
“What right do we have to do things that, even if they don’t affect us, are going to be someone else’s problem a thousand years from now?” asked Ian Joughin, an ice sheet expert at the University of Washington who was not involved in the new research. “Is it fair to do that so we can go on burning fuel as fast as we can?” Caldeira told me recently that he considered this study his most important work and hopes it will help convince world leaders and the public of the scope of what’s being sacrificed for the sake of cheap fossil energy now. In our video chat, he and the other authors acknowledged the challenge in gaining traction, even with such findings, given the deep-rooted human bias toward immediate gratification and the development and energy gaps that mean today’s poorer nations have few affordable choices other than fossil fuels. See my recent look at India’s argument for expanded coal use.) Here are a few snippets from our chat, but I encourage you to listen to the full exchange (and post other excerpts you find noteworthy):
Ken Caldeira on our bias to the immediate:
Last night, at dinner I ate more than I should have, maximizing my pleasure at the expense of my long-term wellbeing. So I have trouble with my own life, optimizing future value and present value. It’s that much more difficult when we talk about doing things for the benefit of people all around the world and for generations far into the future. So this question of how do we motivate people to sacrifice a tiny little bit in the here and now to help everybody for the long term it’s a really tough problem. I don’t have any quick answers but just because it’s tough doesn’t mean it’s not important.
Ricarda Winkelmann on the planet-scale consequences of energy choices made in the next few decades:
It’s real important to think about these long time scales. Essentially, what our study shows is that the changes that we bring upon within the next decades can really change the face of the Earth for thousands of years to come.
Anders Levermann on the significance of carbon dioxide’s long lifetime once emitted:
Another aspect to it that really pushes it into our century, or even our decade, is that we are emitting the carbon now and it stays in the atmosphere for a long time and the temperature remains high even longer than the carbon remains high.