Tuesday, December 9, 2008

Sea Level Rise Halted

Over the months there has been mention in the media of the risk of rising sea levels usually tied to an ice berg or two calving off Green land that I have largely ignored simply because it was inconsequential and a clear bit of throw away pandering to the global warming crowd and at best a pretense.

A minute rise in the sea level had been measured over the decades in any event, long before the current enthusiasm.

This report gives us an update of the current trend and it is obvious that for the past three years, the rise has halted completely. We do not infer more than the fact that the addition of ice in the mountains and ice sheets has now balanced the removal by melting at the foot of glaciers. It has not reversed but that could well change over the next three years.

Again, creditable data truly exists only with the access to satellites. Prior data had to accommodate a variable accounting for the vertical movement of the land itself. That was completely taken out with satellites. The land may well still rise or fall an inch per century but it is no longer needs to be used to measure sea levels directly.

I for one would be happy to see a few years of decline to set in so that future movement has less impact on observers.

5 12 2008

We’ve been waiting for the UC web page to be updated with the most recent sea level data. It finally has been updated for 2008. It looks like the steady upward trend of sea level as measured by satellite has stumbled since 2005. The 60 day line in blue tells the story.


Source: University of Colorado, Boulder

From the University of Colorado
web page:

Since August 1992 the satellite altimeters have been measuring sea level on a global basis with unprecedented accuracy. The TOPEX/POSEIDON (T/P) satellite mission provided observations of sea level change from 1992 until 2005. Jason-1, launched in late 2001 as the successor to T/P, continues this record by providing an estimate of global mean sea level every 10 days with an uncertainty of 3-4 mm.

They also say:

Long-term mean sea level change is a variable of considerable interest in the studies of
global climate change. The measurement of long-term changes in global mean sea level can provide an important corroboration of predictions by climate models of global warming. Long term sea level variations are primarily determined with two different methods.

Yes, I would agree, it is indeed a variable of considerable interest. The question now is, how is it linked to global climate change (aka global warming) if CO2 continues to increase, and sea level does not?

There’s an interesting event in October 2005 that I’ll come back to in a couple of days.
(h/t to Mike Bryant)

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