We covered this earlier, but this is a new press release on the subject today.
From the University of Washington via Eurekalert
Model shows polar ice caps can recover from warmer climate-induced melting
A growing body of recent research indicates that, in Earth’s warming climate, there is no “tipping point,” or threshold warm temperature, beyond which polar sea ice cannot recover if temperatures come back down. New University of Washington research indicates that even if Earth warmed enough to melt all polar sea ice, the ice could recover if the planet cooled again.
In recent years scientists have closely monitored the shrinking area of the Arctic covered by sea ice in warmer summer months, a development that has created new shipping lanes but also raised concerns about humans living in the region and the survival of species such as polar bears.
In the new research, scientists used one of two computer-generated global climate models that accurately reflect the rate of sea-ice loss under current climate conditions, a model so sensitive to warming that it projects the complete loss of September Arctic sea ice by the middle of this century.
However, the model takes several more centuries of warming to completely lose winter sea ice, and doing so required carbon dioxide levels to be gradually raised to a level nearly nine times greater than today. When the model’s carbon dioxide levels then were gradually reduced, temperatures slowly came down and the sea ice eventually returned.
“We expected the sea ice to be completely gone in winter at four times the current level of carbon dioxide but we had to raise it by more than eight times,” said Cecilia Bitz, a UW associate professor of atmospheric sciences.
“All that carbon dioxide made a very, very warm planet. It was about 6 degrees Celsius (11 degrees Fahrenheit) warmer than it is now, which caused the Arctic to be completely free of sea ice in winter.”
Bitz and members of her research group are co-authors of a paper about the research that is to be published in Geophysical Research Letters. The lead author is Kyle Armour, a UW graduate student in physics, and other co-authors are Edward Blanchard-Wrigglesworth and Kelly McCusker, UW graduate students in atmospheric sciences, and Ian Eisenman, a postdoctoral researcher from the California Institute of Technology and UW.
In the model, the scientists raised atmospheric carbon dioxide 1 percent each year, which resulted in doubling the levels of the greenhouse gas about every 70 years. The model began with an atmospheric carbon dioxide level of 355 parts per million (in July the actual figure stood at 392 ppm).
In that scenario, it took about 230 years to reach temperatures at which the Earth was free of sea ice during winter. At that point, atmospheric carbon dioxide was greater than 3,100 parts per million.
Then the model’s carbon dioxide level was reduced at a rate of 1 percent a year until, eventually, temperatures retreated to closer to today’s levels. Bitz noted that the team’s carbon dioxide-reduction scenario would require more than just a reduction in emissions that could be achieved by placing limits on the burning of fossil fuels. The carbon dioxide would have to be drawn out of the atmosphere, either naturally or mechanically.
“It is really hard to turn carbon dioxide down in reality like we did in the model. It’s just an exercise, but it’s a useful one to explore the physics of the system.”
While the lack of a “tipping point” could be considered good news, she said, the increasing greenhouse gases leave plenty of room for concern.
“Climate change doesn’t have to exhibit exotic phenomena to be dangerous,” Bitz said, adding that while sea ice loss can have some positive effects, it is proving harmful to species such as polar bears that live on the ice and to some people who have been forced to relocate entire villages.
“The sea ice cover will continue to shrink so long as the Earth continues to warm,” she said. “We don’t have to hypothesize dramatic phenomena such as tipping points for this situation to become challenging.”
The research was funded by the National Science Foundation, the Davidow Discovery Fund and the National Oceanic and Atmospheric Administration.
For more information, contact Bitz at 206-543-1339 or bitz@atmos.washington.edu, or Armour at 858-610-3812 or karmour@uw.edu.
The paper is available at http://www.agu.org/journals/pip/gl/2011GL048739-pip.pdf.
Duh!
If the earth cools, polar ice will increase? And this the resulst of the billions of dollars spent on climate science?
We are all suckers.
I wonder what we get for a million dollar study these days. Anybody know?
Let’s see, this study:
1) Reaffirms the role CO2 in regulating the earth’s temperature
2) Says there’s less ice with more CO2 and that ice can recover if you lower the CO2.
3) If it gets warmer the ice goes away, but if it gets colder, the ice comes back.
Hmmm….they got paid how much to do this study?
Bystander says:
Please give your tired canard a rest will you?
R. Gates says:
August 17, 2011 at 8:48 pm
Simply replace CO2 with H20 and you’ve got some very sound physics.
It takes heat energy to make less water ice and more liquid/vaporous H20.
So, where does this heat energy come frome?
Direct from the Sun, and stored from the Sun.
Ah, darnit, R.Gates, there’s that blasted Sun again.
Tell you what: If somebody were to calculate the heat energy released from all the burning of fossil fuels per year, then we could have a really nifty dataset to look at. And, not only that, but we could have a first look at how much Solar Energy has been stored over millions of years by Life on Earth.
We did this at school. Glass of water in freezer turns to ice. Take the glass out it melts.
Amazing what tax dollars can do. A study that finds that cold causes water to become ice, even after it melted while it was previously warm.
There is not enough recoverable fossil fuel in the world to generate more than 5 – 600 PPM atmospheric CO2 even after it was ALL burnt up according to Peter Tans (2009) Further he estimates given current consumption rates, peak values will be reached and will start to decline by 2029 – 2069.
http://www.tos.org/oceanography/issues/issue_archive/issue_pdfs/22_4/22-4_tans.pdf
So, if you are going to model CO2 from fossil fuel consumption, you would need to have some baseline reality injected into your model about just how much CO2 CAN be generated, rather than fantasy values resulting in 3,100 ppm in 70 years.
Oops
@ur momisugly Allencic 7.46pm: exactly what I wanted to say 🙂 Why on Earth don’t these so-called researchers actually research the real world instead of inventing computer models and ignoring what has happened many times before?
The latest results from Spencer and others indicates that a quadrupling of CO2 would cause under 3 deg of warming, not 6. Winter sea ice will never be gone. Summer ice has disappeared at the North Pole several times in the 20th century, and it won’t be a disaster the next time.
Meanwhile, our only climate worries are the Solar Minimum and a Big Volcano.
R. Gates says:
August 17, 2011 at 8:48 pm
Let’s see, this study:
1) Reaffirms the role CO2 in regulating the earth’s temperature
2) Says there’s less ice with more CO2 and that ice can recover if you lower the CO2.
3) If it gets warmer the ice goes away, but if it gets colder, the ice comes back.
Hmmm….they got paid how much to do this study?
===========
You ask how many college education loans this study paid off ?
That is another transparent fact our Government is holding in reserve, until the election is near.
Not to worry though, it’s all about the science.
However, the model takes several more centuries of warming to completely lose winter sea ice, and doing so required carbon dioxide levels to be gradually raised to a level nearly nine times greater than today. When the model’s carbon dioxide levels then were gradually reduced, temperatures slowly came down and the sea ice eventually returned.
“We expected the sea ice to be completely gone in winter at four times the current level of carbon dioxide but we had to raise it by more than eight times,” said Cecilia Bitz, a UW associate professor of atmospheric sciences.
“All that carbon dioxide made a very, very warm planet. It was about 6 degrees Celsius (11 degrees Fahrenheit) warmer than it is now, which caused the Arctic to be completely free of sea ice in winter.”
Completely ignoring the fact that atmospheric CO2 has been much higher—over 10 times the current level in the the late Ordovician—during an ice age and around the same level during much warmer regimes.
http://ff.org/centers/csspp/library/co2weekly/2005-08-18/dioxide.htm
“It is really hard to turn carbon dioxide down in reality like we did in the model. It’s just an exercise, but it’s a useful one to explore the physics of the system.”
Only if the physics were correctly modeled.
“Climate change doesn’t have to exhibit exotic phenomena to be dangerous,” Bitz said, adding that while sea ice loss can have some positive effects, it is proving harmful to species such as polar bears that live on the ice and to some people who have been forced to relocate entire villages.
Polar bears don’t need ice to survive and entire villages have been abandoned when glaciers expanded in the Alps.
This “study” is so full of … FAIL.
…one of two computer-generated global climate models…
They are able to generate models by computers now? Give me a break. They may throw millions of models at us in a very short time to keep us busy refuting them. Meanwhile…
Besides, “one of two”? The other one was a denier? Why not three of fourteen?
“BioBob says:
August 17, 2011 at 9:57 pm
There is not enough recoverable fossil fuel in the world to generate more than 5 – 600 PPM atmospheric CO2 even after it was ALL burnt up according to Peter Tans (2009) Further he estimates given current consumption rates, peak values will be reached and will start to decline by 2029 – 2069.”
Estimates of the amounts of recoverable “fossil fuels” — especially clathrates are all over the place. But your basic point has a good deal of merit. It is quite unclear that we humans could push atmospheric CO2 to the levels used in this simulation even if we wanted to. Unless, of course the CO2 sequestration mechanisms — which we do not remotely understand — quit working.
“Werner Brozek says:
August 17, 2011 at 8:22 pm
“All that carbon dioxide made a very, very warm planet. It was about 6 degrees Celsius (11 degrees Fahrenheit) warmer than it is now, which caused the Arctic to be completely free of sea ice in winter.”
Back to the drawing boards! According to http://ocean.dmi.dk/arctic/meant80n.uk.php, it would take a 30 C increase at the north pole to make it ice free in winter.”
Werner, I’m inclined to agree that the likelihood of the North Pole — which has nearly six months of no sunlight at all and very low sun angles even during “Summer” not being well below -2C in Winter is very low. But you do need to keep in mind that the hypothetical 6C rise is not expected to be evenly distributed. What is modeled is — I’m sure — no or slight warming in the tropics and rather dramatic warming — way more than 6C — in the high latitudes.
Is it just me or has science training abdicated the role of commonsense in recent years?
It’s not long since a UK university funded an expensive, long study to discover if sheep could recognise individual humans ! That they can is something known to shepherds throughout history (I keep a few sheep) and that could have been ‘researched’, recorded and ‘discovered’ in at most 3 days by visiting a handful of shepherds with their flocks.
It seems to me that it has become an industry in itself where for too many universities and scientific institutions try to create a marketplace for research (with scare stories) to generate income. Too often that seems to result in worthless studies carried out to establish nothing new and nothing of value.
This study, as so many have pointed out, is not only pointless but fails to appreciate that the artcic winter temperature would need to rise by 30 degrees and more for it to become ice free.
If public money has been used to fund research such as this then whoever authorised it needs to be held to account for wasting tax-payers money.
Anything is possible says:
August 17, 2011 at 5:54 pm
Bottom line :
Heat ice above zero degrees and it melts. Cool the water below zero degrees and it re-freezes.
Anyone need a multi-million pound computer model to tell them that?
Anyone earning a living out of government grants.
I just read the book “The Farthest North” by Frijodolt Nansen. It chronicles their trip across the polar ice in the ship the “Fram” in 1893-1896. A very interesting read and some absolutely first rate science with temperatures, depth soundings, salinity measurements (at depth) and a plethora of other data regarding conditions across the polar ice. The ship reached as high as 85 degrees 47 minutes and Nansen and his crew mate Johansen made it to 86 degrees 14 minutes.
The detailed records of this trip would be a valuable addition to climate science.
Hint there is a lot of information there that I have NEVER seen included in the computer models of the ice, including the intrusion of the gulf stream as high as 85 degrees latitude.
Did you hear about the scientist who originally went to university to become a model.
I really like the idea that they have more than one model and then pick the one that suits their current argument. With only two models to play with at the moment I can see that they would need a lot more “investment” in a full range of models to ensure that all bases are covered.
It would be interesting to see if the model reproduced the greater temperature variability during periods of falling global temperatures compared to rising periods, that is observed over both short (decadal) and long (millenial) time scales – e.g. Vostok ice core.
I would guess not.
Has anyone told the drinks industry that water freezes? could help keep my Pimms cold during the summer.
Might have to run a few thousand more sims to confirm that water does freeze though, just to be sure, now where’s my grant.
Post normal science full of newspeak, big brother would be proud,its good news week, idiots pretending to do science.
Anthony
Seems a shame to ban the clown (bystander). He does no harm and provides some rare laughs in these difficult times. But, there again, you’ve banned him so why not out him. That could be real fun.
Old England says:
August 18, 2011 at 12:50 am
You are highlightinga point I made a long time ago. When the UK dumded down universities and dumbed up polytechniques ,it created a massive group of student’s with no intentions of working for a living. So they became experts in grant application in order to remain at school for the rest of their lives at your expense. Climate change-global warming became the holy grail.