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Global warming: 70 feet of sea level rise?

 2 to 3 feet of sea level rise expected this century

A relatively small increase in ocean temps could trigger a meltdown of the West Antarctic ice shelf, resulting in a significant rise in sea levels.

By Summit Voice

SUMMIT COUNTY — Scientists continue to grapple with the question of how global warming will affect sea levels, looking at evidence of past climate change to try and determine how the future will play out.

In one of the latest studies, researchers from Rutgers University looked at rock and soil cores in Virginia, Eniwetok Atoll in the Pacific and New Zealand, dating back to the Pliocene epoch, 2.7 million to 3.2 million years ago — the last time concentrations of carbon dioxide in the atmosphere were as high as they are now, and atmospheric temperatures were 2 degrees C higher than they are now.

“The natural state of the earth with present carbon dioxide levels is one with sea levels about 20 meters higher than at present,” said Kenneth G. Miller, professor of earth and planetary sciences in the School of Arts and Sciences at Rutgers University. “The current trajectory for the 21st century global rise of sea level is 2 to 3 feet (0.8 to1 meter) due to warming of the oceans, partial melting of mountain glaciers, and partial melting of Greenland and Antarctica.”

The findings suggest that sea levels were so high during that Pliocence that the volume of extra water equaled the amount frozen in the entire Greenland and West Antarctic Ice Sheets, as well as some of the marine margin of the East Antarctic Ice Sheet, according to H. Richard Lane, program director of the National Science Foundation’s Division of Earth Sciences, which funded the work.

“Such a rise of the modern oceans would swamp the world’s coasts and affect as much as 70 percent of the world’s population,” Lane said.

“You don’t need to sell your beach real estate yet, because melting of these large ice sheets will take from centuries to a few thousand years,”Miller said.

Miller said the research highlights the sensitivity of the earth’s great ice sheets to temperature change, suggesting that even a modest rise in temperature results in a large sea-level rise.

There is plenty of evidence that the West Antarctic ice sheet has melted a previously, including during the Pliocene. Some studies suggest that a 5 degree increase in ocean temps could trigger a collapse. The ice sheet melted and refroze several times, with each phase taking only a few thousand years.

 

 

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6 Responses

  1. I think it is happening much quicker.

  2. Indeed, I agree with onefly, that it is happening much quicker. The warming of the Tundra which also has CO2 as well as methane locked up inside, is another source that is affected by the temperature rise. The fact that the scientific research is accumulating in such volumes over the many disciplines today, can’t be discarded as more junk science as some would like to say. Food for thought.

  3. [...] Scientists continue to grapple with the question of how global warming will affect sea levels, looking at evidence of past climate change to try and determine how the future will play out. Read more. [...]

  4. I would tend to agree with onefly as well. In the Pliocene the forcing due to CO2 was hundreds of times slower than at present. The models these scientists are using are based on these times and how well they describe the current situation is pretty doubtful. The arctic in general and ice in particular are highly unstable, non-linear systems, which is why the effects of warming have been underestimated pretty consistently by “the experts”. Jim Hansen’s recent work is one of the few that shows the exponential behavior of ice sheet disintegration.

  5. Yes, the west slope of Antarctica is ground zero for concern about significant, rapid sea level rises because 80% of the Earth’s glacier ice is stored at the South Pole. A very ambitious and action-oriented proposal is offered at http://dolphinblueinc.wordpress.com/2009/09/23/proposed-effort-to-slow-melting-of-glacier-in-antarctica/ for how melting of ice in Antarctica could be slowed. The proposed solution would be extraordinarily costly. However, the ultimate costs of inaction, as described in Bob Berwyn’s article, would be much greater.

    If every nation in the world would accept global warming as an existential threat, solutions could be implemented that are commensurate with the threat. A budget of $2 trillion per year (approximately what is spent on wars and military preparedness) would do the job. See http://www.dolphinblue.com/pg-Update–Energy-Island-a-Solution-to-Global-Warming.html for an update on the feasibility of an ocean-based solution to global warming that uses proven technologies.

    Long-term, global warming could be a blessing if it forces people to stop fighting and start cooperating. That has happened before when enemies have become allies to counter a common threat. Our political leaders should stop partisan bickering and protecting short-term profits of fossil fuels companies. Rather, politicians should look at global warming as a problem so serious it requires common action and a worldwide turn in consciousness toward cooperation and peace. They should start now.

  6. [...] University in the US and Prof Tim Naish from Victoria University of Wellington in New …Global warming: 70 feet of sea level rise?Summit County Citizens VoiceEven with global warming reined in, rising sea levels pose threat to [...]

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