Why Climate Models Underestimated Arctic Sea Ice Retreat: No Arctic Sea Ice in Summer by (2100?)

[OKIsItJustMe]

http://www.sciencedaily.com/releases/2011/10/111006084040.htm

Why Climate Models Underestimated Arctic Sea Ice Retreat: No Arctic Sea Ice in Summer by End of Century?

ScienceDaily (Oct. 12, 2011) — In recent decades, Arctic sea ice has suffered a dramatic decline that exceeds climate model predictions. The unexpected rate of ice shrinkage has now been explained by researchers at CNRS, Université Joseph Fourier and Massachusetts Institute of Technology. They argue that climate models underestimate the rate of ice thinning, which is actually about four times faster than calculations. This model bias is due to the poor representation of the sea ice southward drift out of the Arctic basin through the Fram Strait. When this mechanism was taken into account to correct the discrepancy between simulations and observations, results from the new model suggested that there will be no Arctic sea ice in summer by the end of the century.

…

The Arctic has been losing about 10% of its permanent ice layer every ten years since 1980. Melting of Arctic sea ice has also reached record heights: in mid-September 2007, at the point when sea ice reaches its annual minimum extent, perennial ice covered an area of 4.14 million km²(1). This record low level was nearly reached again in September 2011 (4.34 million km2). Climate simulations conducted for the IPCC(2) simulate the decline in Arctic sea ice resulting from global warming. They predict that summer ice will disappear altogether at the end of this century. However, when compared with 30 years of detailed satellite observations, these models appear optimistic. Arctic sea ice has thinned on average four times faster over the period 1979-2008 than in the climate simulations. True observations are therefore not correctly reproduced by these climate models, which were mainly calibrated using global variables, such as world average rather than "regional" temperature.

An explanation for this difference has been put forward by a Franco-American team, involving in particular the Laboratoire de glaciologie et géophysique de l'environnement (CNRS / Université Joseph Fourier). It may be due to a misrepresentation of the mechanical behavior of pack ice and the drift of sea ice in the models. To demonstrate this, the researchers examined the mechanisms of sea ice drift with respect to their physical state (thickness and concentration), then analyzed the model predictions in combination with field data. In 2009, these same scientists demonstrated that there had been a significant acceleration of ice drift in recent decades. This can now be explained by ice thinning, which has accelerated. Sea ice has become thinner and more fragile. Because it breaks up more easily, its mobility is increased, as is its export from the Arctic Ocean through the Fram Strait between Greenland and the Svalbard archipelago, followed by its melting. This mechanism may be exacerbating the present decline in Arctic sea ice.

The drift of sea ice is poorly described by the models, which do not take drift acceleration or southward evacuation of the ice into account. "Modeled" sea ice behaves as though it drifts freely, without any mechanical interaction between ice fragments, whatever the season, period or ice thickness. There is no link in the models between the thinning of the ice and the further acceleration of its drift.

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http://dx.doi.org/10.1029/2011JC007110

[truebrit71]

1. 2100? Try before 2020....

...that is a much more realistic number imho...

[defendandprotect]

3. Agree --- and the further dangers of diluting the salinity of North Atlantic ....

is that it, "in turn, could slow or stop the movement of a major Atlantic Ocean

current whose warmth has kept the climate of northern North America and northern

Europe hospitable to civilization."

"If it failed -- result would be rapid deep freeze that would basically make much

of the Northern Hemisphere incapable of supporting societies."


In 2003 -- "there was a startling report that the entire eco system of the North Sea

is in a state of collapse -- with devastating implications for fisheries and wildlife."


"Record sea temperatures are killing off the plankton on which all life in the sea

depends because they underpin the entire marine food chain. Fish stocks and sea birds

populations have slumped."



Quotes from Ross Gelbspan's books on Global Warming --

[defendandprotect]

2. We are only feeling the effects now of human activity up to 1960 ... !!!!

That is why Global Warming effects will be accelerating even faster than before --

Think of all we did post-1960!!


Scientists since the 1880's and the Industrial Revolution have known the negative impact

on nature/trees caused by "bus-i-ness" -- we would have been better off NOT engaging in

occupations to create profits for the few. We'd still have our freedom and the planet/

nature.


The glaciers have been melting since the 1940's and the build up for WWII --

and scientists are constantly shocked at the rapid melting -- beyond all expectations.


Not only will Global Warming bring chaotic weather in increasing numbers and severity --

droughts/floods -- cyclones, tornados, hurricanes, storms --

but it will also bring increasing numbers of earthquakes and more severe earthquakes.

This is why it is essential for citizens to begin to turn their attention -- as Fukushima

did 6 years or so ago -- to shutting down the nuclear reactors across America. It could

make the difference between "a whimper or a bang" -- !!

Fukushima tried to shut down their reactors 6 years ago based on Japanese scientists

reporting increasing seismic activity on this earthquake-prone island -- PLUS the age

of the reactors and the fact that they were built to withstand only 7.1 earthquakes.

The last earthquake was a 9+ --


Imagine the suffering for Japan and the world had Fukushima's government been able to

carry out their plans to shut down these reactors.



How could such an insane idea as using nuclear energy to boil water to produce steam

have ever been moved from the military into Japan? And into every one of our states?