NCAR says targeting specific pollutants would slow SLR

From the  National Center for Atmospheric Research/University Corporation for Atmospheric Research

I can see the EPA jumping all over this one. Black carbon is likely a contributor, as it changes the albedo of ice sheets and one that is much easier to manage. Problem is, the USA isn’t much of a black carbon emitter any more, but India and China are. – Anthony

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Cutting specific pollutants would slow sea level rise

BOULDER – 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 sea level rise 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 carbon dioxide 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 coastal cities if it moves quickly on a handful of pollutants.”

The study, a collaboration of the Scripps Institution for Oceanography, 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 carbon dioxide concentrations 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 effects of climate change. 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 glaciers 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 carbon dioxide emissions 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 rising sea levels. 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 sea level 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 emissions.”

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The University Corporation for Atmospheric Research manages the National Center for Atmospheric Research under sponsorship by the National Science Foundation. Any opinions, findings and conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

About the article

Title: Mitigation of short-lived climate pollutants slows sea-level rise

Authors: Aixue Hu, Yangyang Xu, Claudia Tebaldi, Warren M. Washington, and Veerabhadran Ramanathan (corresponding author)

Publication: Nature Climate Change

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A summary the paper is available here: http://www.igsd.org/news/documents/SLRsummary8April13355pmEDT4.pdf

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28 thoughts on “NCAR says targeting specific pollutants would slow SLR

  1. “Problem is, the USA isn’t much on a black carbon emitter any more….”
    And exactly why would this stop them?

  2. And on Aussie MSM tonight, Antarctic ice is melting 10 times faster than previously thought. No references, just “scientists” say.

  3. I love it…”With coastal areas bracing for rising sea levels…..” That’s pretty rich, NCAR! Or is it writer’s licence on the part of the reporter? Please, tell us, exactly WHERE these coastal areas are? And show us the crowds of worried people “bracing”…I can’t quite understand where that fabrication comes from…..! Where were the people “bracing” eight years ago as New Orleans was swamped? Where are the worried faces in the headlong rush to build on seashores prone to storm surge? What utter crap–honestly. And as a lead-in sentence to a bit of publically-funded ‘research’, a sure fire stinker. Remove that introduction, and the ‘impact’ of this ‘research’ becomes a fizzling dud.

  4. Everybody should disconnect those low-flow shower heads. Put in a koi pond in the backyard. That will tie up so much extra water, sea levels will go down.
    Think globally, act locally — that’s my motto

  5. China is discovering right now what happens when they don’t limit soot emissions. They’ll see their way to a solution or they’ll never see Beijing again.

  6. “Some scientists, however, feel those estimates are too conservative.”
    Yes and some think these estimates are too high – typical alarmism bias of NCAR shining through – of course their continued funding depends on alarming claims.
    “With this in mind, the research team focused on emissions of four other heat-trapping pollutants: methane, tropospheric ozone, hydrofluorocarbons, and black carbon.”
    Sounds like they are throwing in the towel on CO2 & moving onto the alarming cause

  7. I thought Africa with its widespread fire burning was the soot leader. And since when have sea levels been rising in an alarming fashion? I might add that China and India are years ahead of the Western countries in nuclear build rates, which constitutes the only effective way to reduce all types of pollutants. Also, everything in this country moves via diesel powered trucks, which seem to produce an awful lot of soot.

  8. What sea level rise? In the figures that JustTheFacts put up here yesterday, one reasonable estimate of sea level change has sea level rising at a rate of 1.19 meter per millenium. Another has it at 1.6 meter per millenium.

  9. It’s all about money, the more they can frighten the gullible masses, the more money they will get for ‘research.’

  10. Sea level rise averaged over one meter per century the past 12,000 years since the end of the Ice Age. However, since the end of the Little Ice Age the average has only been 6 inches per century (so our anomaly is presently a negative 2.5 feet per century), and during the Little Ice Age sea level fell. Therefore, what we need is another Ice Age. The last big one dropped sea level over 120 meters, which would solve one problem, but create another: all the port cities would be high and dry, and they would want that less than having to adapt to slowly rising sea level. Incredibly, that’s what the Dutch have been doing, and they have gotten very good at it while waiting for the next ice age so they can get back to world-class canal ice skating.
    I’m surprised that these scientists didn’t try to pick some really low-hanging fruit, like vastly increasing nuclear power through developing liquid fluoride thorium reactors (LFTR) like the Chinese are, which would enable plant starvation through greatly reduced CO2 emissions (and black soot, which the Chinese are already working on now anyway), and stop ground water depletion through greatly increased desalinization. Ground water depletion has been a significant contributor to the rather modest sea level increase of the past century, and it would be a good thing to reduce its depletion regardless of sea level considerations.
    Unfortunately for these rent-seeking scientists, solutions to many ecological problems are already in the pipeline, driven by increasing prosperity in the developing world as a result of rapidly increasing energy production and use.
    Prosperity works to save the environment everywhere it is tried.

  11. Since when has soot become “black carbon”? Can somebody help with finding the origins of the word?
    When was this first time used?
    To my paranoia it looks like an attempt to call carbon a pollutant. What is it with “black carbon”? Is there a “white carbon” to differentiate from? Why don’t people call soot: soot?
    Does it sound more elevated or what?
    http://books.google.com/ngrams/graph?content=%22black+carbon%22&year_start=1800&year_end=2010&corpus=15&smoothing=3&share=

  12. So unless we react now, the rising sea levels will cause ships to run aground in all commercial harbours?
    What rising sea levels? Where?
    And with even the team admitting to a pause in rising temperatures, what is driving this imaginary increase in sea levels?

  13. I’m math challenged or literacy challenged. The current rise is 3 mm/year or 30 cm/century. If we do nothing the rise will be between 18 cm and 59 cm. So, if we do nothing the rise could decrease, be the same or maybe double. But since we are 13% of the way through the century, doubling sea level rise means the rate has to slightly more than double. Does this happen slowly or all at once? Another one of those “we can control the climate” but this time they can also control the sea level rise.
    I’m all for scientific research and using models, but it doesn’t seem that the modelers even try to connect connect those models to reality. These folks should be in environmental air permitting where you are required by regulation to use models that are not much connected to reality.

  14. Reductions in the adjustments of raw data “… would slow sea level rise …” even more robustly.
    Pay me.

  15. “….. especially when storm surges hit.”
    Many places already have storm surge defenses.
    23 inches per century equals one brick higher every 15 years or so.
    Couldn’t we cope with that?

  16. Permanent Service for Mean Sea Level (PSMSL), lists 10 tide gauge stations on the West coast of Canada with near continuous monthly data from 1973 through 2011. The graph below shows the average monthly sea level of the 10 tide gauge stations. The black line is the linear best fit to the data. Over the period 1973 to 2011 the average best-fit sea level has declined at 0.5 mm/year, or declined 19 mm over 39 years.
    http://www.friendsofscience.org/assets/documents/FOS%20Essay/Sea_Level_Canada_West.jpg

  17. So, in a hundred years time they measure the sea level rise and declare that it would have been 30% higher (insert figure in cms) had we not implemented the findings of their study.
    Of course if sea levels reduce or remain constant then they could also claim the credit.
    Now that is not what I would call genuine science, but it’s a nice little earner for the researchers.

  18. No worry’s the EPA will fix it with Obama’s encouragement. They will close down the last vestiges of industry and power generation. Pump more money into Solar and Wind. Yep, they’ll teach China and India a lesson!
    Sarc off.

  19. The Japanese, or is it the Chinese, have sea level data that seems to show a long term oscillation. If this cycle is real, the question is, “where are we in the cycle?”
    People making these sort of sea level rise predictions are going to look pretty darn stupid if we are currently nearing a high point and sea levels start to decline. The data does seem to show a slight deceleration in the underlying, but rather small, positive trend.
    I have said before that anyone who implies linear trend for extrapolation to climate data is on a fools errand.
    I suspect that the future will mark the IPCC reports as a total load of codswallop!
    or is that already happening

  20. “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.”
    Interesting, even with raising CO2 emissions, the reduction of the “short-lived pollutants” will reduce more then 50% of the warming? This means the effect of Carbon dioxide is significantly less then half!
    It gets even more interesting:
    “The study assumes that society could reduce emissions of the four gases and particles by 30 to 60 percent over the next several decades.”
    Now I am confused. If reduction of the four gases by 30 to 60% would reduce warming by about 50%… hm?… what remains then as the warming effect of Carbon Dioxide?
    “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.”
    OK, so the satellite measured sea level rise….
    “As glaciers 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,”
    …. will be potentially down to what tide gauges measure – around 1.1-1.2 mm per year?
    Geographically weighted average, mm per year: 1.1331
    Of course, this is ignoring GIA and other adjustments, just the rise of the sea against the shore in average as measured by the tide gauges:
    http://www.burtonsys.com/climate/MSL_global_trendtable1.html
    Well yes, 1.1331 gives 11.33 cm per century, 18 cm – 7.56 (42% of 18 cm)=10.44cm, that will fit in the range, easy to achieve as this is what the data is telling us is currently happening.

  21. To Lars P, regarding definitions of “soot,” “black carbon,” and “white carbon”:
    Lars, I doubt you would be surprised that words are used to create whatever impression the user wants, when it comes to the very politicized issue of pollution.
    “Soot’ has no scientific meaning. When most of us think of soot, we think of black, harmful stuff, but when EPA or the Sierra Club refer to reductions of emissions from U.S. coal plants, which is almost entirely sulfate, they use the word “soot,” I assume because it has a negative gut connotation. If I asked you what sulfate looks like, what would your answer be? The answer is, a whitish haze.
    “Black carbon” to air pollution researchers has a more specific meaning. BC is partially burned, dark carbonaceous material, with a core of pretty much pure carbon. When airborne, it is dark and absorbs heat (the opposite of sulfate on a dry day, which as a whitish haze reflects light back to space, thus cooling the planet a bit). Wikipedia has a good discussion of black carbon.
    Organic carbon in the air is a reflective whitish haze, but I’ve never heard it called “white carbon.” Organic carbon is made up of a number of different organic compounds which are in the size range of tiny particles. A forest fire, or crop burning, produces both organic carbon and some black carbon, but more organic.
    For a full inventory of black carbon (BC) and organic carbon (OC), here is one excellent publication:
    A Technology-Based Global Inventory of Black and Organic Carbon Emissions from Combustion
    T. C. Bond, D. G. Streets, K. F. Yarber, S. M. Nelson, J.-H. Woo, Z. Klimont
    Journal of Geophysical Research, 109, D14203, doi:10.1029/2003JD003697, 2004.
    We present a global tabulation of black carbon (BC) and primary organic carbon (OC) particles emitted from combustion. We include emissions from fossil fuels, biofuels, open biomass burning, and burning of urban waste. Previous “bottom-up” inventories of black and organic carbon have assigned emission factors based on fuel type and economic sector alone. Because emission rates are highly dependent on combustion practice, we consider combinations of fuel, combustion type, and emission controls, and their prevalence on a regional basis. Central estimates of global annual emissions are 8.0 Tg for black carbon and 33.9 Tg for organic carbon. These estimates are lower than previously-published estimates by 25 to 35%. The present inventory is based on 1996 fuel-use data, updating previous estimates that have relied on consumption data from 1984. An offset between decreased emission factors and increased energy use since the base year of the previous inventory prevents the difference between this work and previous inventories from being greater. The contributions of fossil fuel, biofuel, and open burning are estimated as 38%, 20%, and 42% respectively for BC, and 7%, 19%, and 74% respectively for OC. We present a bottom-up estimate of uncertainties in source strength by combining uncertainties in particulate matter emission factors, emission characterization, and fuel use. The total uncertainties are about a factor of two, with uncertainty ranges of 4.3 to 22 Tg/year for BC and 17 to 77 Tg/year for OC. Low-technology combustion contributes greatly to both the emissions and to the uncertainties. Advances in emission characterization for small residential, industrial, and mobile sources, and top-down analysis combining field measurements and transport modeling with iterative inventory development, will be required to reduce the uncertainties further.

  22. The best way to reduce sooty cooking fires in the tropics would be to give away millions of cooking-type “rocket stoves.”
    The best way to reduce sooty heating fires in the termperates would be to incentive the replacement of fireplaces and heating stoves with heating-type rocket stoves. Rocket heaters are very efficient and produce no visible smoke. At present, there are YouTube videos and online design plans on how to make one oneself from junkyard items (e.g., old water heaters and propane tanks), which requires non-trivial welding skills. A good design plan is here: http://www.iwilltry.org/b/build-a-rocket-stove-for-home-heating/. It’s followed by miles of comments and answers. There are no off-the-shelf rocket stove heaters for sale.

  23. could temporarily forestall the rate of sea level rise by roughly 25 to 50 percent…..
    Wouldn’t ‘stop jiggling with the data’ be a lot cheaper and quicker?

  24. “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.”
    More like since projected sea level rise by 2100 is less than 6 inches as it is, a 30% reduction to 4 inches of rise just doesn’t get anyone excited. Can’t convince people to lower their standard of living, drastically increase the cost of their energy and give up what little freedoms they have left if you don’t scare them.

  25. Carbon is black. Get over it. It’s not about “black” Carbon either. Would “black” Carbon explain why the Arctic was nearly ice free in the 1930’s, and completely ice free for most of the last 600 million years?
    Carbon limited algae will gleefully consume your “black” Carbon. Did I forget to mention that cyanobacteria live in ice and snow? You probably know not to eat yellow snow. Don’t eat red snow either.

  26. We’re not even sure how fast sea level is rising. As Lattitude notes, much of the rise is due to “jiggling with the data”. From ‘GPS Aids in Sea Level Rise Debate’:
    “The range of estimates published in the literature is rather wide (1 to 3 mm/yr), with figures converging towards 1.8 mm/yr.”
    After they nail down the exact rate of sea level rise using reproducible GPS measurements, then we can decide if we need to worry. The article is well worth a read:
    http://www.worldclimatereport.com/index.php/2010/02/09/gps-aids-in-sea-level-rise-debate/

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