Top U.S. Climate Scientist Issues New Warning On Catastropic Sea Level Rise

[cal04]

James Hansen, the head of NASA’s Goddard Institute Of Space Studies and the top U.S. climate scientist, has issued a new warning about the threat of a catastrophic rise in sea levels. He warns further that many scientists aware of such a rise are reluctant to discuss it out of fears of appearing “alarmist.”

From Hansen’s new paper in the journal Environmental Research:

I suggest that a “scientific reticence” is inhibiting the communication of a threat of a potentially large sea level rise. Delay is dangerous because of system inertias that could create a situation with future sea level changes out of our control. I argue for calling together a panel of scientific leaders to hear evidence and issue a prompt plain-written report on current understanding of the sea level change issue.

Climate Progress has more. This week, CNN’s Anderson Cooper has been reporting live from the source of much of this sea level rise — the disappearing glaciers in Greenland. Last night, Cooper interviewed biologist Jeff Corwin, who laid out the massive changes taking place in Greenland:

Today, it’s actually losing ice at about 100 billion tons a year. I mean, that’s incredible. One hundred billion tons of ice is disappearing. And, of course, it just doesn’t go up in smoke. The ice melts. Not only do you have to deal with water being lifted up, with the potential sea level going up virtually 20 feet, but also salinity. People aren’t thinking about this problem. What happens when a saltwater environment becomes more fresh lake?

Watch Cooper’s excellent report:
http://thinkprogress.org/2007/05/26/sea-level-rise/

[Stargleamer]

1. Rudy after 9/11: "I'm glad we have * as our President"

yeah, the guy who responds to pseudo-threats posed by Iraq and ignores real ones such as global warming.

[n2doc]

2. There's a comment in there that is very odd

The whole "Not only do you have to deal with water being lifted up, with the potential sea level going up virtually 20 feet, but also salinity. People aren’t thinking about this problem. What happens when a saltwater environment becomes more fresh lake?" Comment betrys a real lack of understanding. If all ice on earth melted, salinity might change by 0.1 part in a thousand in the oceans. It is now about 35 parts per thousand, 35 grams salt per kilogram seawater, now. The volume of the oceans is gigantic. 1.37 billion cubic kilometers. Ice is .03 billion cubic kilometers.

[shraby]

3. I'd worry more about the fresh water becoming

salty as the sea encroaches on land.

[n2doc]

4. That is a very serious problem already

Down in Florida and Georgia there is a huge aquifer that most cities and farms get their fresh water from. As water is removed salt water comes in. The wells around Charleston are already going salt. This is happening in Palestine as well, an underlying issue that will eventually lead to catastrophe.

[ConsAreLiars]

5. Your Exxon talking points are misleading. If you are actually interested

in what changes in North Atlantic salinity will mean, see this article. http://www.whoi.edu/page.do?pid=12455&tid=282&cid=9986


"What can disrupt the Ocean Conveyor?
Solving this puzzle requires an understanding of what launches and drives the Conveyor in the first place. The answer, to a large degree, is salt."

[TwilightGardener]

9. Yep--I've heard that too--the effect on ocean currents, and then climate, could be disastrous.

[n2doc]

11. Bite me. I know a hell of a lot more about ocean currents than you do

And frankly, no one knows what is going to happen with the conveyor. All the hypotheses now out there are based on a very different event, the Younger-Dryas event, where a huge amount of fresh water was released essentially instantaneously out the St. Laurence into the North Atlantic. That ain't the issue here and if you had any knowledge about the issue, instead of talking points lifted from folks trying to get more funding, you would know this to be true. I've given talks at WHOI, have you?
AC implies the OCEANS would get more fresh. That is what I was addressing.

[whopis01]

16. Wow.... someone's ego was stepped on. n/t

[eppur_se_muova]

7. Averaged out, yes, but that will take time.

In the meantime, that flood of fresh water is causing the ocean in the immediate area to become less dense. This makes it harder for cold water to sink downwards, and if the density drops low enough, the "conveyer belt" thermohaline system in the Atlantic may slow down drastically, stop, reverse, or reorganize in some new pattern.

from http://www.cru.uea.ac.uk/cru/info/thc/

Will the thermohaline circulation collapse?

The critical part of the thermohaline circulation (THC) is the sinking in the North Atlantic Ocean. This occurs here (and not in the North Pacific) because the Atlantic is much more saline (and hence, denser). It is more saline because it is warmer (more evaporation of fresh water increases the salinity of the sea water). It is warmer in the North Atlantic because warm water is brought by the thermohaline circulation from the tropical and South Atlantic. To some extent, therefore, the THC appears to be self-sustaining. And if some event occurs to break this self-sustaining chain of processes, then there is the potential for the circulation to break down rapidly (i.e., over several decades) and to remain in a reduced-circulation state for several centuries.

Some fairly simple models of the world's oceans do simulate a rapid break down of the THC, when the density of the water in the North Atlantic Ocean is lowered by adding fresh water (rain) and/or by warming. Increased rainfall and warming over the North Atlantic are both expected as a result of increased greenhouse gas concentrations, and so it can be argued that global warming may cause a rapid collapse of the thermohaline circulation. The self-sustaining system described above is, however, much more complex in reality, and the more complete climate models, that take some of these complexities into account, generally simulate only a gradual weakening of the THC in response to global warming. Nevertheless, observations and palaeoclimate evidence both indicate that the THC has fluctuated both recently and in the distant past.

The majority of climate scientist believe that a critical change in the THC is unlikely to occur during this century, but the question cannot be answered with certainty at present. Due to the potentially serious impact on our climate of a collapse of the THC, it must be regarded as a low-risk, high-impact event that cannot be ignored.

[Maestro]

8. And if that happens Mother Nature will just reset itself

and cause another Ice Age and warm waters will not circulate in the northern hemisphere; however, the extent of the next Ice Age can not be determined because of all the greenhouse gases in the atmosphere.

[Morgana LaFey]

14. The desalinization would occur around the Greenland area, not

around the whole rest of the world -- maybe not forever but at least initially. And climate scientists have been worried for quite some time now about that lack of salinity altering the flow of the ocean current (and their winds) that keep Europe relatively moderate since salt water and fresh water behave differently (one sinks, the other doesn't -- forget which -- which affects the temperature of the water at the surface and at depth and that affects the movement of the currents).

[Lisa]

15. perhaps he's thinking of local/regional effects?

Although ocean water does circulate, the mixing is not complete so salinity is not evenly distributed. The Baltic, for example, is less salty than the ocean water along the equator (where there's a lot of evaporation). It's been suggested by researchers, such as Wallace Broecker, that a large pulse of fresh water entering the North Atlantic (due to the melting of the Greenland ice sheet) could disrupt the thermal and salinity gradients, and therefore the "thermo-haline" circulation patterns.

p.s. I see that earlier posters have already made this point -- I should add that I don't know enough about marine biology to say if there are any organisms that might be especially susceptible to changes in salinity/temperature, in any affected parts of the ocean.

[pinto]

6. The current Nat'l Geographic has a good piece on the Greenland glaciers,

Antarctic coastal ice pack, various other glacier research data from around the world.

'The Big Thaw'

http://www7.nationalgeographic.com/ngm/0706/feature2/index.html

[Doremus]

10. Last night, Cooper interviewed biologist Jeff Corwin, who laid out the massive changes taking place

I agree that Anderson Cooper's reports from Greenland have been very good, I just wish he could have found a better tour guide.

Jeff Corwin is okay, but he's hardly an expert in environmental issues. Heck, he isn't even that great with animals, his stock in trade. He squealed so much when that elephant grabbed his arm I thought for sure it was broken or dislocated. Neither, just a red mark. :eyes:

Too bad Anderson didn't find himself a more credible spokesperson.

[CK_John]

12. Have no fear, the condo developers are on the way. n/t

[Warren DeMontague]

13. "Scientist"- there's your problem, right there. Has anyone asked the Pope?

How about Pat Robertson? The Discovery Institute? Or the folks at Answers in Genesis and the Creation Museum?

What does THE BIBLE have to say about all this- after all, THE BIBLE is THE MOST AUTHORITATIVE WORK OF SCIENCE KNOWN TO MAN!

THE BIBLE Has God's Plan for YOU and ME, and if it doesn't explicitly mention the ice caps melting, then it's not happening!!!

...

Hey- think I can get a job with The Bush Administration, now?