Scientists outline long-term sea-level rise in response to warming of planet

Jul 15, 2013
ocean

A new study estimates that global sea levels will rise about 2.3 meters, or more than seven feet, over the next several thousand years for every degree (Celsius) the planet warms.

This international study is one of the first to combine analyses of four major contributors to potential sea level rise into a collective estimate, and compare it with evidence of past sea-level responses to global temperature changes.

Results of the study, funded primarily by the National Science Foundation and the German Federal Ministry of Education and Research, are being published this week in the Proceedings of the National Academy of Sciences.

"The study did not seek to estimate how much the planet will warm, or how rapidly sea levels will rise," noted Peter Clark, an Oregon State University and author on the PNAS article. "Instead, we were trying to pin down the 'sea-level commitment' of global warming on a multi-millennial time scale. In other words, how much would sea levels rise over long periods of time for each degree the planet warms and holds that warmth?"

"The simulations of future scenarios we ran from physical models were fairly consistent with evidence of sea-level rise from the past," Clark added. "Some 120,000 years ago, for example, it was 1-2 degrees warmer than it is now and sea levels were about five to nine meters higher. This is consistent with what our models say may happen in the future."

Scientists say the four major contributors to sea-level rise on a global scale will come from melting of glaciers, melting of the Greenland ice sheet, melting of the Antarctic ice sheet, and expansion of the ocean itself as it warms. Several past studies have examined each of these components, the authors say, but this is one of the first efforts at merging different analyses into a single projection.

The researchers ran hundreds of simulations through their models to calculate how the four areas would respond to warming, Clark said, and the response was mostly linear. The amount of melting and subsequent sea-level response was commensurate with the amount of warming. The exception, he said, was in Greenland, which seems to have a threshold at which the response can be amplified.

"As the ice sheet in Greenland melts over thousands of years and becomes lower, the temperature will increase because of the elevation loss," Clark said. "For every 1,000 meters of elevation loss, it warms about six degrees (Celsius). That elevation loss would accelerate the melting of the Greenland ice sheet."

In contrast, the Antarctic ice sheet is so cold that elevation loss won't affect it the same way. The melting of the ice sheet there comes primarily from the calving of icebergs, which float away and melt in warmer ocean waters, or the contact between the edges of the ice sheet and seawater.

In their paper, the authors note that sea-level rise in the past century has been dominated by the expansion of the ocean and melting of glaciers. The biggest contributions in the future may come from of the Greenland ice sheet, which could disappear entirely, and the Antarctic , which will likely reach some kind of equilibrium with atmospheric temperatures and shrink significantly, but not disappear.

"Keep in mind that the projected by these models of 2.3 meters per degree of warming is over thousands of years," emphasized Clark, who is a professor in Oregon State University's College of Earth, Ocean, and Atmospheric Sciences. "If it warms a degree in the next two years, sea levels won't necessarily rise immediately. The Earth has to warm and hold that increased temperature over time.

"However, carbon dioxide has a very long time scale and the amounts we've emitted into the atmosphere will stay up there for thousands of years," he added. "Even if we were to reduce emissions, the commitment of global warming will be significant."

Explore further: Wetlands not 'wetting' enough for invertebrates

More information: The multimillennial sea-level commitment of global warming, www.pnas.org/cgi/doi/10.1073/pnas.1219414110

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axemaster
4.5 / 5 (10) Jul 15, 2013
This study may seem a bit useless to many of you, but it's definitely very important to be able to calculate the sea level equilibrium position if you want to have accurate near-term sea level rise predictions.
Kiwini
1.5 / 5 (23) Jul 15, 2013
NikFromNYC
1.6 / 5 (26) Jul 15, 2013
News flash: the vast majority of long running tide gauge records show utterly no high CO2 trend change, unless you count a mild leveling off of many of them...

http://s23.postim...andy.gif

A movie of these is here:

http://www.youtub...dxhpDq6A
deepsand
2.9 / 5 (21) Jul 16, 2013
As usual, NYC Nikky widely misses the mark.
NikFromNYC
1.6 / 5 (25) Jul 16, 2013
EVER NOTICE THAT ALL THESE MISERABLE PEOPLE EVER OFFER IS SNIDE INNUENDO?

My job is done here. Thanks Mr. Deepsand: you are today the public face of Global Warming. My, how your numbers have dwindled!\

Phys.org which is owned by a green energy con$ulting company has a "Report" button for abuse, but it doesn't work for skeptics.
NikFromNYC
1.6 / 5 (26) Jul 16, 2013
This study itself backtracks by factors of 10 claims of multi-meter sea level rise by 2100 by the vast majority of alarmist supporters and does so by rescaling their claims from a hundred to thousands (or hundreds of thousands!) of years. From dusty academic halls they soberly ignore the clearly trivial ability of 2100 humanity to block out some sunlight with little mirror satellites or a bit of nuclear powered atmospheric aerosols, all the while failing to mention that their vast reduction in century scale sea level rise means we can use fracking now to massively boost Western economies so to naturally support huge boosts in general science funding that windmills won't afford.
alfie_null
4 / 5 (13) Jul 16, 2013
EVER NOTICE THAT ALL THESE MISERABLE PEOPLE EVER OFFER IS SNIDE INNUENDO?

My job is done here. Thanks Mr. Deepsand: you are today the public face of Global Warming. My, how your numbers have dwindled!\

Phys.org which is owned by a green energy con$ulting company has a "Report" button for abuse, but it doesn't work for skeptics.

The "Report" button is to help eliminate that cheap-stuff-for-sale spam that occasionally sneaks in. It occurs to me, that we see your full-of-rhetoric but mostly content free rants is a good indication that they otherwise don't interfere with what's posted. Contrary to your impugned claims of bias.
Egleton
3.4 / 5 (16) Jul 16, 2013
He'll still be ranting when he is up to his neck in water.
vlaaing peerd
4.1 / 5 (14) Jul 16, 2013
if he's from NYC, he already was last summer. Apparently didn't help, Nik's starting to talk about nuclear powered aerosols now.

Funny it's actually technology derived from age old windmills that will prevent his city from flooding again.
VendicarE
3.9 / 5 (15) Jul 16, 2013
"News flash: the vast majority of long running tide gauge records show utterly no high CO2 trend change" - NikkieTard

With the thermal capacity of the ocean so spectacularly large, and the delta T of the atmosphere only 0.76'C so far, why would you expect to see any change in the rate?

Perhaps it is because you are a fool who doesn't have a clue.
VendicarE
3.9 / 5 (15) Jul 16, 2013
"This study itself backtracks by factors of 10 claims of multi-meter sea level rise by 2100 by the vast majority of alarmist supporters and does so by rescaling their claims from a hundred to thousands (or hundreds of thousands!) of years." - NikkieTard

Typically researchers who are studying sea level rise conclude that by 2100 the total sea level rise will be less than 1 meter, with a potential of around 1 meter.

However, over the longer term the rise will be substantially higher due to the melting of the Antarctic and Greenland ice caps.

How muchhigher depends on how far in the future you wish to look.

Once again NikkieTard is guilty of misrepresentation.
VendicarE
3.7 / 5 (14) Jul 16, 2013
"EVER NOTICE THAT ALL THESE MISERABLE PEOPLE EVER OFFER IS SNIDE INNUENDO?" - NikkieTard

I wasn't aware that identifying you as a lying, low life, moron, was Innuendo.
geokstr
1.6 / 5 (20) Jul 16, 2013
The "Report" button is to help eliminate that cheap-stuff-for-sale spam that occasionally sneaks in.

1) If enough people use the report button, as I do with every one of the comments that are abusive, uncivil and filled with vicious personal attacks, the moderators will be inundated with reports, and eventually have to take note and do something about it (yes, I even report the comments I agree with when they return fire in the same way.)

2) If you get fed up enough after hundreds of these type comments from the same internet bully wannabes (you know who you are), use the "Contact" selection at the bottom of every page to specifically report in detail those who are most abusive. This is why Vendicar(Decarian,A,B,C,D,E,F,.....Zz) has had to move on to the next letter now and then when the they ban/suspend the last one.

Make sure you remind the moderators that such abuse will lead to fewer page hits. Even those on the left understand that.
Neinsense99
3.4 / 5 (17) Jul 16, 2013
This study itself backtracks by factors of 10 claims of multi-meter sea level rise by 2100 by the vast majority of alarmist supporters and does so by rescaling their claims from a hundred to thousands (or hundreds of thousands!) of years. From dusty academic halls they soberly ignore the clearly trivial ability of 2100 humanity to block out some sunlight with little mirror satellites or a bit of nuclear powered atmospheric aerosols, all the while failing to mention that their vast reduction in century scale sea level rise means we can use fracking now to massively boost Western economies so to naturally support huge boosts in general science funding that windmills won't afford.


Bollocks.
Howhot
4.7 / 5 (12) Jul 16, 2013
Reading geokstr post... it says;
If enough people use the report button, as I do with every one of the comments...
I thought so. Typical of some of the looser Antropogenic global warming denier and anti-climate-change whiners. If you can't win the vote, poison it, just like the republicans do.
deepsand
2.7 / 5 (12) Jul 26, 2013
EVER NOTICE THAT ALL THESE MISERABLE PEOPLE EVER OFFER IS SNIDE INNUENDO?

My job is done here. Thanks Mr. Deepsand: you are today the public face of Global Warming. My, how your numbers have dwindled!\

Phys.org which is owned by a green energy con$ulting company has a "Report" button for abuse, but it doesn't work for skeptics.

That's real cute, blaming others for your own shortcomings and then declaring victory.

Best confine your activities to playing with your chemistry set ... outdoors, of course.