Albedo feedback: Climate models underestimate loss of reflectivity in the Arctic

Loss of reflectivity in the Arctic is double the estimate used in current state-of-the-art climate models according to new analysis of the Northern Hemisphere's "albedo feedback" over a 30-year period. The research comes hard on the heels that Greenland had a record melt during 2010.

The albedo feedback is the change in the reflectivity of surfaces in a constant reinforcing feedback loop. In the Arctic snow and ice is highly reflective. Global warming has reduced sea ice exposing darker ocean and increased the size of dark melt pools on the Greenland ice sheet, which then increases the warming effect on ice in a positive feedback.

"The cryosphere isn't cooling the Earth as much as it did 30 years ago, and climate model simulations do not reproduce this recent effect," said Karen Shell, an Oregon State University atmospheric scientist and one of the authors of the study. "Though we don't necessarily attribute this to global warming, it is interesting to note that none of the climate models used for the 2007 International Panel on Climate Change report showed a decrease of this magnitude."

"Instead of being reflected back into the atmosphere, the energy of the sun is absorbed by the Earth, which amplifies the warming," Shell said. "Scientists have known for some time that there is this amplification effect, but almost all of the climate models we examined underestimated the impact - and they contained a pretty broad range of scenarios."

Mark Flanner, assistant professor in the Department of Atmospheric, Oceanic and Space Sciences University of Michigan, also involved in the research, analyzed satellite data showing snow and ice during the past three decades in the Northern Hemisphere, which holds the majority of the planet's frozen surface area.

Flanner said "If the Earth were just a static rock, we could calculate precisely what the level of warming would be, given a perturbation to the system. But because of these feedback mechanisms we don't know exactly how the climate will respond to increases in atmospheric carbon dioxide,"

"Our analysis of snow and sea ice changes over the last 30 years indicates that this cryospheric feedback is almost twice as strong as what models have simulated. The implication is that Earth's climate may be more sensitive to increases in atmospheric carbon dioxide and other perturbations than models predict." Flanner comented.

The research has been published in Nature Geoscience - Radiative forcing and albedo feedback from the Northern Hemisphere cryosphere between 1979 and 2008. The abstract says in part:

"We find that cyrospheric cooling declined by 0.45 W m-2 from 1979 to 2008, with nearly equal contributions from changes in land snow cover and sea ice. On the basis of these observations, we conclude that the albedo feedback from the Northern Hemisphere cryosphere falls between 0.3 and 1.1 W m-2 K-1, substantially larger than comparable estimates obtained from 18 climate models."

"Some of the decline may be natural climate variability," Shell said. "Thirty years isn't a long enough time period to attribute this entirely to 'forcing,' or anthropogenic influence. But the loss of cooling is significant. The rate of energy being absorbed by the Earth through cryosphere decline - instead of being reflected back to the atmosphere - is almost 30 percent of the rate of extra energy absorption due to carbon dioxide increase between pre-industrial values and today."

The reserach comes hard on the heels that Greenland had a record melt during 2010.

While climate models have sometimes suffered from criticism for being too sensitive, this study shows current models have underestimated the feedback effect. "People sometimes criticize models for being too sensitive to climate perturbations" Flanner said. "With respect to cryospheric changes, however, observations suggest the models are a bit sluggish."

"While the current group of models underestimates these Northern Hemisphere cryosphere changes, new models will be released this year that will have better representations of snow and ice," Shell said. "This study will help climate modelers improve the new generation of models to better predict the rate of cryosphere and albedo decline in the future.



REAL liberals are not climate change believers.
REAL liberals doubt, question and challenge authority from media, politicians, green corporations and corporate science. REAL liberals don’t bow to a politician who is making an election promise of lowering the seas and making the weather better with taxes. REAL liberals don’t wish, hope and pray for a climate crisis to happen,“just to show‘em!”. REAL liberals were happy, overjoyed and relieved about climate change being 100% wrong and thus avoiding massive suffering for our children from a dying planet caused by CO2. REAL liberals don’t sit in the dark for an hour once a year with the lights turned out and call it being radical. REAL liberals don’t look their kids in the eyes and tell them they will die an unspeakable death from unstoppable warming on a dying planet. REAL liberals don’t condemn billions to death by CO2. REAL liberals are open-minded and don’t demonize any opposing view and call it “neocon”. The real necons of fear, lying and war mongering are the climate change believer terrorists leading us to a false war of climate change. BUSH-GORE-LIBERALSIM?
How is creating a fake stock market for a fake commodity of "CARBON" supposed to be anti-capitalist. What has happened to real liberals. I'm sick of spewing the hate for necons when it's us doing the fear mongering.

This example is symptomatic for what happened with the conservative mind when it became obvious that unbalanced capitalist expansion is a threat to the planet. To compensate for its notorious inability to grasp the facts and change the situation, it is clinging to obsolete groupthink and strawman scares. It does not reject the carbon trade because that is a scam designed to keep fossile energy prices below the external cost of use, but because it intends to cheat us over these cost without any figleaf. Whenever it drops the name climate change, in fact it does not refer to actual atmospheric developments but to a bureaucratic narrative which has nothing to do with the daily lives of environmentalist activists. Except for the pollution of course, which threatens all of us alike regardless whether we do something against it or try to pretend to ourselves that it wasn't harmful.