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Scientist: 'Risks of Massive Changes in the Climate System'
Greenland thaw among feared climate shifts by 2200
OSLO - A drastic climate shift such as a thaw of Greenland's ice or death of the Amazon forest is more than 50 percent likely by the year 2200 in cases of strong global warming, according to a survey of experts.
A climate activist dressed as a penguin holds up a sign reading "Give me back my iceberg!" during a protest outside the European Commission headquarters in Brussels, March 12, 2009. (REUTERS/Francois Lenoir)
The poll of 52 scientists, looking 100 years beyond most forecasts, also revealed worries that long-term warming would trigger radical changes such as the disintegration of the ice sheet in West Antarctica, raising world sea levels.
"There's concern about the risks of massive changes in the climate system," said Elmar Kriegler of the Potsdam Institute for Climate Impact Research, lead author of the study in the U.S. journal Proceedings of the National Academy of Sciences.
Huge changes or "tipping points," which might also include a slowdown of the warm Gulf Stream current that keeps Europe warm, are often dismissed as highly unlikely or scaremongering.
The survey issued late on Monday found that leading experts, when asked, reckoned there was a one in six chance of triggering at least one tipping point with a moderate temperature rise of between 2 and 4 Celsius (3.6-7.2 Fahrenheit) by 2200 from 2000.
But with a strong rise of between 4 and 8 Celsius by 2200, the chances of surpassing at least one of five tipping points reviewed rose to 56 percent.
"The study shows that some of these events are not considered low probability," Kriegler told Reuters of the study, with colleagues in Germany and Britain.
He said the poll was relevant to government policymakers because any of the climate shifts examined would have huge economic impacts.
"The results of the survey provide further evidence for the need of ambitious climate protection in order to minimize the risks of far-reaching consequences for our entire planet," Hans Joachim Schellnhuber, director of the Potsdam Institute who was among the authors, said in a statement.
GREENLAND
Most likely of five tipping points was the onset by 2200 of a longer-term Greenland thaw that would make it largely ice free. Greenland contains enough water to raise world sea levels by 7 meters if it ever all melted.
Second most likely was a death of large tracts of the Amazon rainforest because of a drying trend, followed by the start of a disintegration of the West Antarctic ice sheet, which would raise seas by about 5 meters.
The other two potential tipping points, a collapse of the system of Atlantic currents including the Gulf Stream and a shift toward a constant El Nino warming of the Pacific Ocean, were considered far less likely.
The survey was taken in late 2005 and early 2006, in parallel with much of the writing of the last U.N. Climate Panel report that said that a build-up of greenhouse gases from human activities was the main cause of warming.
That U.N. report focused only on the coming century and said that "abrupt climate changes...are not considered likely to occur in the 21st century."
(Editing by Charles Dick)
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14 Comments so far
Show AllIn a 100 years? What sort of conservative think tank group of scientists is this from?
Many scientist predict these things in less than 50 years.
Others are predicting less than 20 years.
I for one would rather that our collapsing civilization be cautious and plan for the worst case scenario.
Anything else is just playing Russian roulette with all life on the planet.
Note that the survey results, only now being reported, are from more than three years ago - much has changed since, then as field reports keep showing accelerating changes that exceed anticipated ranges. It was really only in 2005 that these field reports began consistently setting off alarms that climate destabilization had arrived.
So if the same survey were taken today, certainly the percentages of alarmed scientists would be much higher than reported here.
This is a strange article. Monbiot's CD article today makes things sound a lot more urgent than 2200. Most discussion has been out to 2100, with similar probablilities as these guys are giving for 2200.
"The survey issued late on Monday.... The survey was taken in late 2005 and early 2006."
Real timely, huh? As clearcut-climate notes, predictions based on more recent data are far worse, and a current survey would likely reflect that. I go along with Lovelock, that even the small amounts of forcing we've seen to date are far beyond what climatologists expected, which is to say the dire consequences of human behavior will come sooner and be much greater than anticipated.
Ironic that the only human thing that may outlive the human race is probably the Voyager spacecraft soaring quietly along in the dark reaches of space beyond the solar system. Maybe we should have called it Ozymandias.
and a giant plastic island in the pacific http://www.independent.co.uk/environment/the-worlds-rubbish-dump-a-garbage-tip-that-stretches-from-hawaii-to-japan-778016.html
and nuclear waste
Actually, the Pioneer and Voyager spacecraft will last many billions of years in the interstellar environment, so they are guaranteed to outlast humanity. Thats' why those records carried by them, containing images songs and greetings of humanity are so precious.
---USAn---
Unless the Klingons use them for target practice.
There will be a certain justice if the worst of climate change suffering comes sooner, rather than later, and is inflicted on the generation most responsible for it. Of course, many of those suffering will be the young and poor, who are not responsible for the disaster. But if we all have to go down, I'd like to see the politicians and bankers go down with us. I think I could die happy if I saw Dick Cheney choke a few seconds before I did.
i like that idea...................shame about the young and poor though.
It is time to plan for the continued cool down that we are experiencing.
All nations should have a grain reserve to tap while the sun continues its vacation. The expected decline in ag production because of the drop in temps will cause more social unrest and starvation than anything in history.
FROM THE YEAR 2000: " The Great Ice Age ", by Wilson, J L Chapman and others, is a VERY scientific look at the macro-situation of earth and humanity.
The charts of Jms Hansen from his website are very clear. See the lecture at Va Tech.
"Under a Green Sky" is also scientific and very informative.
In the 3-4 yrs since this article times have shortened by a third.
And now for your updated Arctic methane release forecast:
The north shore of Spitzbergen has been ice-free all winter this winter. That's amazing! It's March, and the Bering Sea ice has retreated the last 15 days. I wonder, will there be any ice up in the Arctic Ocean at all by September?
The 11 year solar cycle has periods of more sunspots and a small % more warmth from the sun and less sunspots and a small % less warmth. We are going into a few solar cycles with a slightly cooler sun. This will appear to slow global warming but then when the solar cycle changes into more sunspots in the middle to late part of the 21st Century there will be a sudden large increase in the temperature of the planet. There is some evidence in the geological past for big changes in world temperatures in a matter of weeks; that would cause hurricane gale winds over much of the planet and ecological collapse. The scientists are wildly underestimating global warming. When the ozone hole closes up over Antarctica about 2050 then the main part of Antarctica will quickly warm up. According to some scientists there’s geologically evidence of the above sea level area of Antarctica melting in about 50 years. Thus we could have a 200 foot increase in sea level by the end of the century or soon after not 2200. Also sulfur gas producing bacteria which has started off of Namibia will sweep the oceans poisoning the air as in the Permian Extinction when 90% of land life died and 95% of sea life. Only the elite and their chosen technicians will be given space in the underground and domed cities. 2/3rds of the population will be left to die slow painful deaths by poisoned atmosphere. A small number of humans will go to some new Earth like colony worlds in other star systems in the 21st century.