Not by Fire but by Ice


     Email Robert      l     Reviews     l      Order Not by Fire     l     Order Magnetic Reversals      l      Dissenters      l       Recent articles 

Discover What Killed the Dinosaurs . . . and Why it Could Soon Kill Us


Ice-loss estimates double - even triple! -

the truth

Rate of ice loss seriously overestimated



                       page delimiter

8 Sep 10 - The rate at which ice is disappearing from Greenland and Western Antarctica has been seriously overestimated, scientists now admit.

Estimates of the rate of ice loss from Greenland and West Antarctica should be halved, say Dutch and US scientists.

Since 2002, NASA's Gravity Recovery and Climate Experiment (GRACE) satellite data has been used to make an estimate of ice melt from Greenland and Western Antarctica, says this article by Lewis Page.

The rest of Antarctica doesn't seem to be melting at all, says Page. Indeed Antarctica as a whole is actually gaining ice area rather than losing it - but some regions in the West are melting.

Did you catch that? "Antarctica as a whole" is gaining ice. So let me ask you, how can that cause sea levels to rise?
(Also see my article from 2009:
Antarctic ice growing.

According to the new study, previous ice estimates fail to correct for the rebounding of Earth's crust following the last Ice Age.

The miles-thick glaciers that smothered Antarctica and most of the northern hemisphere compressed the crust beneath them.

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

"A good analogy is that it's like a mattress after someone has been sleeping on it all night,"  said lead researcher Bert Vermeersen of Delft Technical University, in the Netherlands.

The weight of the sleeper creates a hollow as the material compress downwards and outwards. When the person gets up, the mattress starts to recover.

"We have concluded that the Greenland and West Antarctica ice caps are melting at approximately half the speed originally predicted," said Vermeersen, whose team worked with NASA's Jet Propulsation Laboratory and the Netherlands Institute for Space Research.

In other words, previous estimates were DOUBLE what they should have been.

With the rebound adjustment modelled in, the loss from Greenland is put at 104 gigatonnes, plus or minus 23 gigatonnes, and 64 gigatonnes from West Antarctica, plus or minus 32 gigatonnes.

This translates into less than 2mm of sea-level rise, says Page. "In the case of Greenland, it could be that the current estimates are triple what they should be."

Lest that slipped by you: In the case of Greenland, current estimates may be TRIPLE what they should be.

"For Greenland in particular, we have found a glacial isostatic adjustment model that deviates rather sharply from general assumptions," says Vermeersen.

I wonder how the Control-and-Tax crowd will try to spin this one.

See entire article:

Also see: Thanks to George Ftizsimmons, Eric Giesbrecht, Heidi Black, Steven Woodcock, Martin and Benjamin Napier for these links

Here's a statement issued yesterday by Vermeersen's university:

The new research can be read here by subscribers to Nature Geoscience, and analysis of it by independent experts can be read (for a fee) here.

See also:
Antarctic Ice Sheet growing
enough to lower sea levels

This paper, published in 2006, shows
that the Antarctic ice sheet is gaining
enough ice to lower – lower! - global
sea levels by 0.08 mm year.
See Antarctic Ice Sheet growing
enough to lower sea levels

.See also:
Much of Antarctica has been cooling for the last 35 years
Thirteen researchers found that temperatures dropped an average of
1.23 degrees Fahrenheit per decade from 1986 to 2000.
See Much of Antarctica has been cooling for the last 35 years







Order Book I Q & A I Book Reviews I Plant Hardiness Zone Maps I Radio Interviews I Table of Contents I Excerpts I Author Photo I Pacemaker of the Ice Ages I Extent of Previous Glaciation I Crane Buried in Antarctic Ice Sheet I Ice Ages and Magnetic Reversals I It's Ocean Warming I E-Mail Robert at l Expanding Glaciers