Humans have already set in motion 69 feet of sea-level rise

[marmar]

from Grist:



31 Jan 2013 8:07 AM

Humans have already set in motion 69 feet of sea-level rise
By Chris Mooney

Last week, a much discussed new paper in the journal Nature seemed to suggest to some that we needn’t worry too much about the melting of Greenland, the mile-thick mass of ice at the top of the globe. The research found that the Greenland ice sheet seems to have survived a previous warm period in Earth’s history — the Eemian period, some 126,000 years ago — without vanishing (although it did melt considerably).

But Ohio State glaciologist Jason Box isn’t buying it.

At Monday’s Climate Desk Live briefing in Washington, D.C., Box, who has visited Greenland 23 times to track its changing climate, explained that we’ve already pushed atmospheric carbon dioxide 40 percent beyond Eemian levels. What’s more, levels of atmospheric methane are a dramatic 240 percent higher — both with no signs of stopping. “There is no analogue for that in the ice record,” said Box.

And that’s not all. The present mass-scale human burning of trees and vegetation for clearing land and building fires, plus our pumping of aerosols into the atmosphere from human pollution, weren’t happening during the Eemian. These human activities are darkening Greenland’s icy surface, and weakening its ability to bounce incoming sunlight back away from the planet. Instead, more light is absorbed, leading to more melting, in a classic feedback process that is hard to slow down. ..................(more)

The complete piece is at: http://grist.org/climate-energy/humans-have-already-set-in-motion-69-feet-of-sea-level-rise/

[abelenkpe]

1. :( nt

[GliderGuider]

2. There are no surprises here...

For the Doomitarians in the crowd, anyway...

[Demo_Chris]

3. 69 feet is hard to believe

NOTE: I am not a climate change denier. If that's the scientific concensus then I believe it.

[muriel_volestrangler]

7. It's the figure for both Greenland and Antarctic melting he thinks is already inevitable

Total potential rise:

Ice sheets contain enormous quantities of frozen water. If the Greenland Ice Sheet melted, scientists estimate that sea level would rise about 6 meters (20 feet). If the Antarctic Ice Sheet melted, sea level would rise by about 60 meters (200 feet).

http://nsidc.org/cryosphere/quickfacts/icesheets.html

[Demo_Chris]

8. Thanks!

[CRH]

4. .

[GliderGuider]

5. Slip Slidin' Away - Ice sheets and sea level in a warming world

Lecture by Richard Alley, Evan Pugh Professor of Geoscience at Pennsylvania State University, 10/23/2012 at Stanford University, sponsored by the Stanford School of Earth Sciences

Richard Alley has the sort of voice and delivery that will either captivate you or annoy you no end, but his grasp of the science is pretty obvious. He dismisses the danger from Greenland (though not the scientific potential), but I think Antarctica gives him bad dreams.

[limpyhobbler]

6. scary, nt

[XemaSab]

9. .

[xchrom]

10. du rec. nt