Climate: New study slashes estimate of icecap loss

PhysOrg.com ^ | Sep 07, 2010 | Richard Ingham

[Arkancide]

Estimates of the rate of ice loss from Greenland and West Antarctica, one of the most worrying questions in the global warming debate, should be halved, according to Dutch and US scientists.

In the last two years, several teams have estimated Greenland is shedding roughly 230 gigatonnes of ice, or 230 billion tonnes, per year and West Antarctica around 132 gigatonnes annually.

Together, that would account for more than half of the annual three-millimetre (0.2 inch) yearly rise in sea levels, a pace that compares dramatically with 1.8mm (0.07 inches) annually in the early 1960s.

But, according to the new study, published in the September issue of the journal Nature Geoscience, the ice estimates fail to correct for a phenomenon known as glacial isostatic adjustment.

This is the term for the rebounding of Earth's crust following the last Ice Age.

Glaciers that were kilometers (miles) thick smothered Antarctica and most of the northern hemisphere for tens of thousands of years, compressing the elastic crust beneath it with their titanic weight.

When the glaciers started to retreat around 20,000 years ago, the crust started to rebound, and is still doing so.

[Wonder Warthog]

Strongly suggest that you read Roy W. Spencer’s new book “The Great Global Warming Blunder”. He makes all these points and more, and gives evidence that the AGW types have confused “cause” and “effect” on the feedbacks in their models. He specifically labels the “water vapor/cloud cover” cycle as being the main controlling negative feedback factor controlling global temperatures (the AGW types assume that said feedback factor is positive rather than negative).

[bIlluminati]

Actually, the guys on the ground in West Antarctica say the ice cover is increasing. Not by much, but no evidence on the ground of net melt/sublimation.

The folks on the ground in East Antarctica? Sorry, no “ground”. It’s all, all covered by ice. And the ice there is increasing, very slowly, because when it’s that cold, it doesn’t snow very much.

[bIlluminati]

There are models that handle water vapor with some accuracy. They’re called weather models. They require fast supercomputers, and have some value for 3-14 days.

Weather is inherently chaotic. Therefore climate is inherently chaotic. Changes in CO2 must be correctly modeled on a daily and yearly basis before the model can be valid.

The so-called Global Climate Models (GCM) oversimplify, and cannot have the sensitivity needed to predict climate. Albedo changes (caused by changes in cloud cover at different altitudes) are critical. Ocean current changes are critical. The GCM do not model any of this in enough detail to pick up chaotic changes and their relative probability. In simple terms, Garbage In, Garbage Out (GIGO).

A good model would predict El Nino/La Nina events and their duration. A good model would have the sunspot cycle and its relation to cosmic rays, which affects cloud formation, rainfall, and albedo. A good model would have random generation of volcanoes.

A good model would have decreased high-sulfur coal burning in Russia and Eastern Europe, starting in 1989, which led to less cloud cover in the Northern Hemisphere , which led to temperatures almost as high as 1934 in 1998. A good model would have the Urban Heat Island effect, and its effects on the thermometer record in urban and rural areas.
The current GCMs, as designed by the Climate “Science” community, have none of this.

[spokeshave]

The “estimate of ice loss” should be labeled “estimate of ice gain”. Glacier Girl landed and was left behind on the Greenland ice sheet in 1942. She was recovered from beneath 270 feet of ice 50 year later: http://en.wikipedia.org/wiki/Glacier_girl How on earth did that aircraft get under 270 feet of ice in 50 years (5.4 feet of ice per year) if the ice sheet is shrinking?

I think its a question of the pressure the aircraft makes in contact with the ice, coupled with the conductivity of aluminum skin/frame...causes the ice to melt under the plane and the water to run off...so plane slowly sinks into the ice

like an ice skate blade is lubricated by melted ice as it passes...

[palmer]

A good model would predict El Nino/La Nina events and their duration

Yep. I would use the word "model" (in real world fidelity). The El Nino would not be predictable just as weather is not predictable. But in a realistic GCM it would occur with the same amplitudes and frequencies, on average, as observed in the real world. As for volcanoes, they have been added but not with decent fidelity because the dispersal of the particulates is quite complex, not well modeled and not well measured to be inputted as a parameter.