Over the past 30 years, temperatures in the Arctic have been creeping up, rising half a degree Celsius with attendant increases in glacial melting and decreases in sea ice. Experts predict that at current levels of greenhouse gases--carbon dioxide alone is at 375 parts per million--the earth may warm by as much as five degrees Celsius, matching conditions roughly 130,000 years ago. Now a refined climate model is predicting, among other things, sea level rises of as much as 20 feet, according to research results published today in the journal Science.

Modeler Bette Otto-Bliesner of the National Center for Atmospheric Research in Boulder and paleoclimatologist Jonathan Overpeck of the University of Arizona matched results from the Community Climate System Model and climate records preserved in ice cores, exposed coral reefs, fossilized pollen and the chemical makeup of shells to determine the accuracy of the computer simulation. Roughly 130,000 the Arctic enjoyed higher levels of solar radiation, leading to increased warming in the summer and the retreat of glaciers worldwide. The model correctly predicted the extent of the resulting Arctic ice melt, enough to raise sea levels by roughly nine feet.

"Getting the past climate change correct in these models gives us more confidence in their ability to predict future climate change," Otto-Bliesner says. "These ice sheets have melted before and sea levels rose. The warmth needed isn't that much above present conditions."

But sea levels rose as much as 20 feet 130,000 years ago and Overpeck speculates that may have been the result of additional melting in Antarctica. After all, the ice there is not all landlocked; some rests in the ocean and a little warming in sea temperatures could melt it or pry it loose. And this time around, the warming is global, rather than concentrated in the Arctic. "In the Antarctic, all you have to do is break up the ice sheet and float it away and that would raise sea level," he says. "It's just like throwing a bunch of ice cubes into a full glass of water and watching the water spill over the top."

Such a sea level rise would permanently inundate low-lying lands like New Orleans, southern Florida, Bangladesh and the Netherlands. Already sea level rise has increased to an inch per decade, thanks to melting ice and warm water expansion, according to Overpeck. And evidence that the Arctic is exponentially warming continues to accumulate. Indeed, in another paper in the same issue of Science, Goran Ekstrom of Harvard University reported a marked increase in so-called glacial earthquakes (seismic events recorded throughout the world when Greenland's glaciers slip past rock) since 2002. In fact, last year alone saw twice as many quakes as in previous years, with most of that increase coming during the summer months.

"We need to start serious measures to reduce greenhouse gases within the next decade," Overpeck says. "If we don't do something soon, we're committed to [13 to 20 feet] of sea level rise in the future."

5 Comments

1. 1. Shoshin 05:33 PM 12/20/08

   Another asinine article. And what about that the much touted IPCC "consensus" on Global Warming comprised polling of 2500 scientists? Of the the 2500 asked, 65 bothered to respond. Of those 65, 57 said they had concerns as to whether anything was happening or not and only 8 said they believed it. But to hear the IPCC tell it 2500 scientists were solidly on board. I guess Goebbels was right, keep repeating the lie enough times and sooner or later everyone will believe it.
   
   And now there's going to be a "Climate Change Secretary". What's next? Ideologically pure energy? This whole movement is as unscientific as creationism.
   
   

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2. 2. Jarmo 06:58 AM 12/15/09

   I want to remember of something:
   There are not many "denyers". But people who question AGW are to be found almost everywhere.
   This is normal for new theories and should be so for AGW. Silence is not science, never was. Only theories who resist critisism has the right to "live". Do you have problem with that Biello?

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3. 3. ozarkoldie 10:47 PM 2/14/10

   How sweet it is!
   Note date.

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4. 4. RAYLB 10:03 PM 3/26/10

   'Asinine' is a good descriptive word for this article., and Overpeck and Otto-Bliesner, the authors quoted in the article need to have their credentials as scientists examined. For instance--Overpeck in his seeking evidence of rising sea levels,said, and I quote him--"Its just like throwing a bunch of icecubes into a full glass of water and watching the water spill over the top" Sea ice--the ice floating on the ocean surface, when melting, adds nothing to the volume of the water. I just this evening proved it for myself. I drew a half glass of water and fininhed filling it with ice cubes till it was brim full. After an hour or so, the ice was melted and not a single drop spilled over. In fact, it appears that the water level has shrunken by an eighth or three sixteens of an inch. Now, if he is thinking about glaciers calving into the ocean, that will add more water but sea ice, if it is floating, it cannot add volume.
   We have had eight major ice ages in the last million years and the graphs of all of them are remarkably similar. I'll agree that civilization and the gross overpopulation of our earth has made a big factor in the speed of the changes, but we are stuck with it all. No one wants to make the changes we know that can give us clean energy (Not in MY Back Yard) and it is verboten to even think about population control, the root cause of all our problems. All I can say is that we are leaving a terrible , terrible legacy for our grandkids and their progeny.

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5. 5. Sgreenovich 11:36 AM 6/7/13

   In a thousand years people will still be getting their <a href="http://memphiscashsaver.com/our-specials/">weekly grocery ads in Memphis</a> unsubmerged and undestroyed. Global weather is not a problem, potential war may be.

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