Friday, December 26, 2008
Hysterical Non Science
Wow, that certainly sounds like a lot of ice turning into water. So how long will it take for all the ice to melt at that rate? Let's see---there is 7.2 million cubic miles of non-sea ice in the Antarctic (up from the estimate in 1974 of merely 6 million) and Greenland has 706,000 cubic miles of non sea ice in its ice cap. Together that's just shy of 8 million cubic miles divided by rounded up 50 cubic miles and we have just 160,000 years until the ice is all gone. Oh, the humanity.
In one of the report's most worrisome findings, the agency estimates that in light of recent ice sheet melting, global sea level rise could be as much as four feet by 2100. The IPCC had projected a sea level rise of no more than 1.5 feet by that time, but satellite data over the past two years show the world's major ice sheets are melting much more rapidly than previously thought. The Antarctic and Greenland ice sheets are now losing an average of 48 cubic miles of ice a year, equivalent to twice the amount of ice that exists in the Alps. (Emphasis added).
But is it really melting in the Antarctic? Here is a different view, a much different view:
From 1992 to 2003, Curt Davis, MU professor of electrical and computer engineering, and his team of researchers observed 7.1 million kilometers of the ice sheet, using satellites to measure changes in elevation. They discovered that the ice sheet's interior was gaining mass by about 45 billion tons per year, which was enough to slow sea level rise by .12 millimeters per year.
The researchers used satellite radar altimeters from the European Space Agency's ERS-1 and ERS-2 satellites to make 347 million elevation-change measurements between June 1992 to May 2003. (Emphasis added).
Well, maybe there's more melting in Greenland. Here is what the Earth Policy Institute says:
Satellite data show Greenland’s ice has been melting at higher and higher elevations every year since 1979. A conservative estimate of annual ice loss from Greenland is 50 cubic kilometers (12 cubic miles) per year, enough water to raise the global sea level by 0.13 millimeters a year.
So, the interior of the Antarctic is lowering the sea level by .12 mm per year (by adding water to the ice sheet there), and the Greenland melting is increasing it by .13 mm per year (by melting into the ocean); then the net gain is .o1 mm per year. That doesn't seem like too much.
Maybe the coastal melting in the Antarctic is adding a lot to rising sea levels. Four feet in 92 years, by 2100, as Ms. Chicken Little writes, means that the sea level would have to rise 13.25 mm per year (1219.2 divided by 92). Well, how has the sea level been doing lately?
Hmmm? The rate is 3.3 mm per year. That's' about 10 mm per year less than would be needed. Indeed, it would take a 400% increase in the rate of sea level rise to get us to a 4 foot higher sea level by 2100. What is the likelihood of that? Well, look at the most recent years (the same years that mean global temperature has plunged). Does it appear that the actual measurements have gotten off the rate of change line? In fact does it appear that during all this supposedly, recently discovered excess melting, the sea level has not increased in the past two years?
And recall that the global rate of sea level rise is merely 20% melt water and 80% thermal expansion, so the melt water addition to sea level is merely .66 mm per year (the rest is warmer water taking up more space). In light of the recent slowing in sea level rise and the recent lack of warming (even, dare I say it, global cooling) 4 feet higher sea level by 2100 seems a real long shot, doesn't it?
(h/t ICECAP and blogger Tom Nelson)
Labels: Global Warming; Disputed Metrics