WAIS Melting Alone Likely To Add 10s Of Centimeters To Overall 1.4 Meter Sea Level Rise By 2100

[hatrack]

EDIT

The Intergovernmental Panel on Climate Change (IPCC) -- whose 2007 report is the scientific benchmark for the UN December 7-18 Copenhagen climate summit -- did not even factor melting ice sheets into its forecasts for rising seas. But studies since then show huge loss of ice mass, mainly as a result of warmer ocean temperatures, according to the review by more than 100 experts on the Scientific Committee on Antarctic Research.

The new evidence suggests that West Antarctica in particular will add "tens of centimetres" to the global ocean watermark, which is predicted to go up two to nine times higher than the IPCC forecast, according to the report. Even the relatively modest IPCC projection of a 18-59 centimetre (7-23 inch) increase by 2100 would render several island nations unlivable and wreak havoc in low-lying deltas home to hundreds of millions.

EDIT

The 550-page report highlights several other recent findings:

-- Earth's most powerful ocean current, the Antarctic Circumpolar Current, has warmed faster than the global ocean as a whole. This is set to disrupt the region's ecosystems, including the rise of alien species that compete with and replace native Antarctic inhabitants. That process has already begun on the Antarctic Peninsula, where rapid warming has resulted in the expansion of plant, animal and microbial communities -- many of them introduced by humans -- on newly thawed land.

-- Sea ice loss and ocean acidification are directly affecting wildlife, and could reduce Antarctica's rich biodiversity, from the bottom to the top of the food chain. Tiny krill have declined significantly, and in some areas Adelie penguin populations have dropped due to reduced sea ice and prey. In other regions, however, notably Ross Sea and East Antarctica, populations of the flightless birds have remained stable or gone up.

EDIT

http://www.terradaily.com/reports/Antarctic_melt_may_push_sea_levels_to_1.4_metres_study_999.html

[kestrel91316]

1. I still don't understand why only the WAIS is of concern down south.

Is there any particular reason why the whole of Antarctica won't melt???

[hatrack]

2. It's a question of which bits melt first . . .

With WAIS at the head of the line (so to speak) it's a question of which parts of the sheet are likely to impact sea levels first and by how much.

Even in worst-case outlooks, the E. Antarctic sheet would likely take centuries to completely melt - it's just that big.

[OKIsItJustMe]

3. WAIS has been known to be melting for some time now

Until rather recently, the Eastern Antarctica Ice Sheet was believed to be holding steady or even gaining mass slightly…

[Nihil]

5. I must admit, that's the bit that I find particularly scary ...

> Until rather recently, the Eastern Antarctica Ice Sheet was believed
> to be holding steady or even gaining mass slightly…

When I saw that article, I had a genuine shiver ... :scared:

With all the "happy clappy" deniers around claiming that the error bars would
make a tiny, almost insignificant increase an "equal" possibility to the
previously predicted mean expectations, very few are prepared to admit that
the opposite end of the same error bar could be pretty catastrophic.

[OKIsItJustMe]

4. ‘Nations will vanish and millions lose their homes to rising seas’

http://www.timesonline.co.uk/tol/news/environment/article6938378.ece

From The Times
December 1, 2009

‘Nations will vanish and millions lose their homes to rising seas’

Hannah Devlin

A rise in sea levels of 1.4m predicted today in a major climate report would result in the loss of entire nations and the displacement of about ten per cent of the world’s population, according to scientists.

The scenario described in the latest report of the http://www.scar.org/">Scientific Committee on Antarctic Research would leave tropical islands such as the Maldives and Tuvalu submerged and result in the loss of large parts of Bangladesh and the Indian Ocean Coast.

In Britain, billions of pounds would have to be spent to protect low-lying cities such as London from being inundated from flood surges that could be even more extreme than the average increase.

“Once set in motion, sea-level rise is impossible to stop. The only chance we have to limit sea-level rise to manageable levels is to reduce emissions very quickly, early in this century. Later it will be too late to do much,” said Professor Stefan Rahmstorf, of the Potsdam Institute for Climate Impact Research in Germany, on whose research the 1.4m figure was based

…