Cutting specific pollutants would slow sea level rise, research says

Apr 14, 2013
ocean

With coastal areas bracing for rising sea levels, new research indicates that cutting emissions of certain pollutants can greatly slow down sea level rise this century.

The research team found that reductions in four pollutants that cycle comparatively quickly through the atmosphere could temporarily forestall the rate of by roughly 25 to 50 percent.

"To avoid potentially dangerous sea level rise, we could cut emissions of short-lived pollutants even if we cannot immediately cut emissions," says Aixue Hu of the National Center for Atmospheric Research (NCAR), the first author of the study. "This new research shows that society can significantly reduce the threat to if it moves quickly on a handful of pollutants."

The study, a collaboration of the Scripps Institution for , NCAR, and Climate Central, is being published this week in the journal Nature Climate Change. It was funded by the National Science Foundation and the Department of Energy.

"It is still not too late, by stabilizing in the atmosphere and reducing emissions of shorter-lived pollutants, to lower the rate of warming and reduce sea level rise," says Veerabhadran Ramanathan of Scripps, who led the study. "The large role of the shorter-lived pollutants is encouraging since technologies are available to drastically cut their emissions."

Protecting the coasts

The potential impact of rising oceans on populated areas is one of the most concerning . Many of the world's major cities, such as New York, Miami, Amsterdam, Mumbai, and Tokyo, are located in low-lying areas by the water.

As and ice sheets melt and warming oceans expand, sea levels have been rising by an average of about 3 millimeters annually in recent years (just more than one-tenth of an inch). If temperatures continue to warm, sea levels are projected to rise between 18 and 59 centimeters (7 to 23 inches) this century, according to a 2007 assessment by the Intergovernmental Panel on Climate Change. Some scientists, however, feel those estimates are too conservative.

Such an increase could submerge densely populated coastal communities, especially when storm surges hit.

Despite the risks, policy makers have been unable to agree on procedures for reducing emissions of carbon dioxide. With this in mind, the research team focused on emissions of four other heat-trapping pollutants: methane, tropospheric ozone, hydrofluorocarbons, and black carbon. These gases and particles last anywhere from a week to a decade in the atmosphere, and they can influence climate more quickly than carbon dioxide, which persists in the atmosphere for centuries.

Previous research by Ramanathan and Yangyang Xu of Scripps, a co-author of the new paper, has shown that a sharp reduction in emissions of these shorter-lived pollutants beginning in 2015 could offset warming temperatures by up to 50 percent by 2050.

Applying those emission reductions to sea level rise, the new research found that the cuts could dramatically slow rising sea levels. Their results showed that total sea level rise would be reduced by an estimated 22 to 42 percent by 2100, depending on the extent to which emissions were reduced.

However, the new study also found that delaying emissions cuts until 2040 would reduce the beneficial impact on year-2100 sea level rise by about a third.

If society were able to substantially reduce both emissions of carbon dioxide as well as the four other pollutants, total sea level rise would be lessened by at least 30 percent by 2100, the researchers concluded.

The researchers used mostly percentage changes for sea level rise, rather than actual estimates in centimeters, because of uncertainties over future temperature increases and their impacts on rising sea levels.

"We still have some control over the amount of sea level rise that we are facing," Hu says.

Another co-author, Claudia Tebaldi of Climate Central, adds:

"Without diminishing the importance of reducing in the long term, this study shows that more immediate gains from shorter-lived pollutants are substantial. Cutting emissions of those gases could give coastal communities more time to prepare for . As we have seen recently, storm surges in very highly populated regions of the East Coast show the importance of both making such preparations and cutting greenhouse gases."

To conduct the study, Hu and his colleagues turned to the NCAR-based Community Climate System Model, as well as a second computer model that simulates climate, carbon, and geochemistry. They also drew on estimates of future emissions of heat-trapping gases under various social and economic scenarios and on computer models of melting ice and sea level rise.

The study assumes that society could reduce emissions of the four gases and particles by 30 to 60 percent over the next several decades. That is the steepest reduction believed achievable by economists who have studied the issue at Austria's International Institute for Applied Systems Analysis, one of the world's leading research centers into the impact of economic activity on climate change.

"It must be remembered that carbon dioxide is still the most important factor in rise over the long term," says NCAR scientist Warren Washington, a co-author. "But we can make a real difference in the next several decades by reducing other ."

Explore further: Tens of thousands expected at New York climate march

More information: Mitigation of short-lived climate pollutants slows sea-level rise, DOI: 10.1038/nclimate1869

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ubavontuba
1.6 / 5 (13) Apr 14, 2013
"We still have some control over the amount of sea level rise that we are facing," Hu says.
That's just so outrageously pretentious that I'm simply held in suspended incredulity.
Jimee
2 / 5 (6) Apr 14, 2013
I would rather my descendants die in sea of poisons than do anything to address reality. Are we sure that the changing climate isn't just following the fashion world's lead? It's HOT this year!
ScooterG
2.3 / 5 (13) Apr 14, 2013
A big portion of this study is simply a back door, underhanded attempt to redefine the word "pollution" to arbitrarily include CO2.

A clever and manipulative bunch, these liberals.
thermodynamics
4 / 5 (8) Apr 14, 2013
A big portion of this study is simply a back door, underhanded attempt to redefine the word "pollution" to arbitrarily include CO2.

A clever and manipulative bunch, these liberals.


Scooter: Are you saying that you think that conservatives are not clever and don't manipulate anything? Just askin'.
John Englander
2.3 / 5 (6) Apr 14, 2013
The reference in the article to the IPCC 2007 assessment projecting 18 - 59 CM of Sea Level Rise (SLR) by end of century if warming is allowed to continue is extremely misleading. That table (IPCC AR4 WG1 SPM.3) says something quite different. There they note quite clearly that those figures do not include "dynamic changes in ice sheets." They explain that there was a lack of published literature at that time that would enable them to quantify the melt rates for the Greenland and Antarctic Ice sheets by the end of century.
In effect the melt rates were increasing so quickly that you could not responsibly put an objective number on what would happen in the next 93 years. So the 18-59 CM essentially is a straight line of the historical, dominated by thermal expansion of seawater and glacial melt. Combined their maximum potential is about 1 meter.
For comparison, Greenland and Antarctica hold more than 60 meters of potential SLR.
ScooterG
2.1 / 5 (11) Apr 14, 2013
A big portion of this study is simply a back door, underhanded attempt to redefine the word "pollution" to arbitrarily include CO2.

A clever and manipulative bunch, these liberals.


Scooter: Are you saying that you think that conservatives are not clever and don't manipulate anything? Just askin'.


I did not say that.

In this thread, we're talking about climate change. I know of no conservatives who are trying to expand the definition of pollution for the express purpose of taxing the populous.
Howhot
3.9 / 5 (11) Apr 14, 2013
A big portion of this study is simply a back door, underhanded attempt to redefine the word "pollution" to arbitrarily include CO2.

I guess you can substitute OIL for CO2 and your sentence works just as well. Unless you want to say Oil is a pollutant. Oil is a pollutant when it is not where it should be. The same is true of CO2.
wyt
4.1 / 5 (9) Apr 15, 2013
A clever and manipulative bunch, these liberals.

Right. You can tell the politics of a scientist because, well, she or he is a scientist! So if it's science, it must have been done by someone politically liberal! Brilliant, you are, to make that observation. Hopefully you can inform us of the inevitable political persuasions of every other occupational category.

Then again, if you'd like to have a few conservative scientists in the world, accusing every scientist whose results you question of being liberal ... yeah, that'll encourage the scientists to ... what? Suppress their results if they contradict your political position, if they want to have their conservative politics fairly recognized despite the inconvenience of their findings to you as their desired friend?
David Lango
1 / 5 (10) Apr 15, 2013
Global warming is no less a hoax than Darwin's theory. If evolution had any merit it would be ongoing. I don't see any half monkey men. I don't see any half sheep horses. I don't see any half ocean goo turning into bugs. I don't see any half in between anything! All I see is a NASA photo of the polar ice cap in September 2012 with a larger line drawn in from 1979 where they neglect to indicate it was from March!

It's a play on the midnight sun, silly! March is after many weeks of 'round the clock darkness, and September is after many weeks of continuous sunlight. The polar ice cap builds and recedes like it has for millenium, and the entire global warming hoax is designed to promulgate the globalists depopulation agenda. The Creator is described as commanding us to "go forth and multiply", not "enjoy playing with the same sex" ie Sodom and Gamorrah.

Keep your powder dry. And if you don't know what that is, get a gun and buy more bullets!
David Lango
1.4 / 5 (10) Apr 15, 2013
A big portion of this study is simply a back door, underhanded attempt to redefine the word "pollution" to arbitrarily include CO2.

A clever and manipulative bunch, these liberals.


Scooter: Are you saying that you think that conservatives are not clever and don't manipulate anything? Just askin'.


I did not say that.

In this thread, we're talking about climate change. I know of no conservatives who are trying to expand the definition of pollution for the express purpose of taxing the populous.


Seriously? Look up Agenda 21. Read all the hundreds of pages. You'll see. Us "carbon units" need to be depopulated from the planet to save it for the handful of super rich globalists who want rule it!

We need to put global warming inside the U.N. building and demo it like they did in 9-11 where it is estimated it took ten tons of nano thermite to take down all three buildings!

Pull it with no people in it this time! Check Larry Silverstein on YouTube!
thermodynamics
5 / 5 (8) Apr 15, 2013
David: Please tighten your tin-foil hat and go to one of the conspiracy sites, not a science site. Evolution a Hoax? At least you put your insanity out there for everyone to see. However, you are going to give denialists and even worse name if you associate global warming with 911 conspiracies. A real live wacko spouting insanity on the site. Thank you for your contribution.
vlaaing peerd
4.1 / 5 (9) Apr 15, 2013
Global warming is no less a hoax than Darwin's theory.


whahahahaha, let me guess... You're American, Republican and Christian. That mix is known to us as a good soil for delusional social views. If we would take your pov we would sentence ourselves to death within the next 40 years. GW is real, rising sea levels are real and here they are already making serious efforts to protect us for the next 200 years.

If all those evil conspiracy scientists are denying you of your beliefs, what are you doing here? They are not going to change reality for you.
PPihkala
5 / 5 (6) Apr 15, 2013
All I see is a NASA photo of the polar ice cap in September 2012 with a larger line drawn in from 1979 where they neglect to indicate it was from March!

It's a play on the midnight sun, silly! March is after many weeks of 'round the clock darkness, and September is after many weeks of continuous sunlight.


Maybe you forgot the fact that at Antarctica the coldest season is the summer and warmest is winter. Therefore September ice is the largest and March is the smallest.
Howhot
4.5 / 5 (8) Apr 17, 2013
Here is the meat; " could temporarily forestall" sea level rise. The problem for the deniers is that sea level rise is already a done deal. Mankind did not stop it's CO2 emissions when it was warned to do so, and destructive sea level rise is the result.
PhotonX
5 / 5 (6) Apr 20, 2013
Well, here we go again. Another political flame war on the science site. Though that has come to be expected, I suppose, whenever global warming is mentioned.
.
I know of no conservatives who are trying to expand the definition of pollution for the express purpose of taxing the populous.
Well, yes, since the definition of the word 'conservative' has gone from meaning 'moderate' in the Rockefeller era to meaning 'radical reactionary' in today's parlance.
.
@David Rango: kevintrs, is that you? Have you finally reavealed your real name? Anyone stupid enough to say something like "I don't see any half sheep horses." is either a troll or a fool.
.
PhotonX
4.4 / 5 (7) Apr 20, 2013
Maybe you forgot the fact that at Antarctica the coldest season is the summer and warmest is winter. Therefore September ice is the largest and March is the smallest.
Apparently he doesn't know the difference between the polar ice cap and Antarctica. Which isn't surprising given his other remarks. He doesn't realize that the extent of Arctic second-year ice is steadily and relentlessly declining.
Benni
1 / 5 (5) Apr 20, 2013
Apparently he doesn't know the difference between the polar ice cap and Antarctica. Which isn't surprising given his other remarks. He doesn't realize that the extent of Arctic second-year ice is steadily and relentlessly declining.


....and the rise in the ocean levels have been how much?
NotParker
1.5 / 5 (8) Apr 21, 2013
CO2 is plant food and has been quite beneficial to agriculture. As the last 15 years have shown, huge amounts of extra CO2 do not increase temperatures.
deepsand
3.2 / 5 (13) Apr 21, 2013
The last 15 years have also shown that NP is a really slow learner.
Howhot
3.9 / 5 (7) Apr 22, 2013
CO2 is plant food and has been quite beneficial to agriculture. As the last 15 years have shown, huge amounts of extra CO2 do not increase temperatures.

That is the dumbest and stupidest thing I have ever heard. No wonder Vendi always used to call you tardpark.
vlaaing peerd
5 / 5 (3) Apr 23, 2013
Apparently he doesn't know the difference between the polar ice cap and Antarctica. Which isn't surprising given his other remarks. He doesn't realize that the extent of Arctic second-year ice is steadily and relentlessly declining.


....and the rise in the ocean levels have been how much?


observed data: 10 cm over the past 50 years, even the most conservative projection till 2100 show a rise of at least another 20 cm.