From the University of Maryland Rising air pollution worsens drought, flooding, UMD-led study shows
COLLEGE PARK, Md. – Increases in air pollution and other particulate matter in the atmosphere can strongly affect cloud development in ways that reduce precipitation in dry regions or seasons, while increasing rain, snowfall and the intensity of severe storms in wet regions or seasons, says a new study by a University of Maryland-led team of researchers.
The research provides the first clear evidence of how aerosols — soot, dust and other small particles in the atmosphere — can affect weather and climate; and the findings have important economic and water resource implications for regions across the United States and around the world, say the researchers and other scientists.
“Using a 10-year dataset of extensive atmosphere measurements from the U.S. Southern Great Plains research facility in Oklahoma [run by the Department of Energy’s Atmospheric Radiation Measurement program] — we have uncovered, for the first time, the long-term, net impact of aerosols on cloud height and thickness, and the resultant changes in precipitation frequency and intensity,” says Zhanqing Li, a professor of atmospheric and oceanic science at Maryland and lead author of the study.
The scientists obtained additional support for these findings with matching results obtained using a cloud-resolving computer model. The study by Li and co-authors Feng Niu and Yanni Ding, also of the University of Maryland; Jiwen Fan of Pacific Northwest National Laboratory; Yangang Liu of Brookhaven National Laboratory, Upton, NY; and Daniel Rosenfeld of The Hebrew University of Jerusalem, is published in the Nov. 13 in Nature Geoscience.
“These new findings of long-term impacts, which we made using regional ground measurements, also are consistent with different findings we obtained from an analysis of NASA’s global satellite products and have just published in a separate study. Together, they attest to the needs of tackling both climate and environmental changes that matter so much to our daily life,” says Maryland’s Li, who is also affiliated with Beijing Normal University.”
“Our findings have significant policy implications for sustainable development and water resources, especially for those developing regions susceptible to extreme events such as drought and flood. Increases in manufacturing, building of power plants and other industrial developments are often accompanied with increases in pollution whose adverse impacts on weather and climate, as revealed in this study, can undercut economic gains,” he stresses.
Tony Busalacchi, chair of the Joint Scientific Committee, World Climate Research Program notes the significance of the new findings. “Understanding interactions across clouds, aerosols, and precipitation is one of the grand challenges for climate research in the decade ahead, as identified in a recent major world climate conference. Findings of this study represent a significant advance in our understanding of such processes with significant implications for both climate science and sustainable development,” says Busalacchi, who also is professor and director of the University of Maryland Earth System Science Interdisciplinary Center.
“We have known for a long time that aerosols impact both the heating and phase changes [condensing, freezing] of clouds and can either inhibit or intensify clouds and precipitation,” says Russell Dickerson, a professor of atmospheric and oceanic science at Maryland. “What we have not been able to determine, until now, is the net effect. This study by Li and his colleagues shows that fine particulate matter, mostly from air pollution, impedes gentle rains while exacerbating severe storms. It adds urgency to the need to control sulfur, nitrogen, and hydrocarbon emissions.”
According to climate scientist Steve Ghan of the Pacific Northwest National Laboratory, “This work confirms what previous cloud modeling studies had suggested, that although clouds are influenced by many factors, increasing aerosols enhance the variability of precipitation, suppressing it when precipitation is light and intensifying it when it is strong. This complex influence is completely missing from climate models, casting doubt on their ability to simulate the response of precipitation to changes in aerosol pollution.”
Aerosol Science
Aerosols are tiny solid particles or liquid particles suspended in air. They include soot, dust and sulfate particles, and are what we commonly think of when we talk about air pollution. Aerosols come, for example, from the combustion of fossil fuels, industrial and agricultural processes, and the accidental or deliberate burning of fields and forests. They can be hazardous to both human health and the environment.
Aerosol particles also affect the Earth’s surface temperature by either reflecting light back into space, thus reducing solar radiation at Earth’s surface, or absorbing solar radiation, thus heating the atmosphere. This variable cooling and heating is, in part, how aerosols modify atmospheric stability that dictates atmospheric vertical motion and cloud formation. Aerosols also affect cloud microphysics because the serve as nuclei around which water droplets or ice particles form. Both processes can affect cloud properties and rainfall. Different processes may work in harmony or offset each other, leading to a complex yet inconclusive interpretation of their long-term net effect.
Greenhouse gases and aerosol particles are two major agents dictating climate change. The mechanisms of climate warming impacts of increased greenhouse gases are clear (they prevent solar energy that has been absorbed by the earth’s surface from being radiated as heat back into space), but the climate effects of increased aerosols are much less certain. Until now, studies of the long-term effects of aerosols on climate change have been largely lacking and inconclusive because their mechanisms are much more sophisticated, variable, and tangled with meteorology.
“This study demonstrates the importance and value of keeping a long record of continuous and comprehensive measurements such as the highly instrumented (ARM) sites run by the Department of Energy’s Office of Science, including the Southern Great Plains site, to identify and quantify important roles of aerosols in climate processes,” says Stephen E. Schwartz, a scientist at Brookhaven National Laboratory. “While the mechanisms for some of these effects remain uncertain, the well-defined relationships discovered here clearly demonstrate the significance of the effects. Developing this understanding to represent the controlling processes in models remains a future challenge, but this study clearly points in important directions.”
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Support for this research was provided by the Department of Energy, NASA, the National Science Foundation and the Chinese Ministry of Science and Technology.
R. Gates says:
November 14, 2011 at 8:35 am
One would have to wonder what the effects would be with CO2 at 280 ppm.
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It can’t be much at all…
Otherwise when any thing caused it to pause, or decrease, when that was removed…
….temps would jump up severely to go back to the same original slope
As it is, the slope just starts over
I agree with the critical comments about length of record and limitations of models. There’s an inherent contradiction when Tony Busalacchi says, “Understanding interactions across clouds, aerosols, and precipitation is one of the grand challenges for climate research in the decade ahead, as identified in a recent major world climate conference” and the results of this study. If the interactions are “grand challenges”, what is the basis for the models?
Claims that this is new research is simply incorrect. I suggest they investigate the Laporte weather anomaly reported by S.A.Changnon Jr in the early 1970s.
http://www.straightdope.com/columns/read/144/do-big-cities-make-the-weather-worse
Or the doctoral thesis of Dr Bruce Atkinson that looked at increased precipitation effects around the London England urban heat island.
http://www.geog.qmul.ac.uk/staff/atkinsonb.html
They should also look at extensive research and practical application on cloud seeding to increase rainfall, as in the US and the former Soviet Union, or for hail suppression as in Penhold Alberta Canada in the1970s and 80s. The latter was abandoned primarily because of inconclusive results. More recently insurance companies in Calgary paid millions to a private company to seed clouds to reduce potential hail insurance claims. To my knowledge it was abandoned after no effective results – something I warned them about. A major problem is you have no reference point. You don’t know how much it would have rained if you hadn’t seeded.
Before Svensmark’s work was confirmed there were discrepancies between known condensation nuclei sources, water droplet formation and cloud cover. Did the authors consider variation in Cosmic ray created nuclei and cloud formation over the period of study?
I am concerned about the serious limitations of the study, but more about the need to justify the work by claiming it resolves planning and political problems. It’s a measure of the degree to which climate science has become politicized and driven by funding, which in turn is only granted to research that pushes the politically correct buttons. It is a vicious, non-scientific circle, which I also watched evolve. To illustrate the point I once proposed a need for funding to find the link between climate and AIDS since these were the biggest buttons for the government funding available to me at the time.
Mike Smith says:
November 14, 2011 at 7:09 am
Well, there a lots of reasons to support reductions in particulate pollution that have nothing to do with climate. The adverse impact of particulate pollution on human health is large and well established.
Of course, but that’s a red herring. Carbonistas, when prompted, will claim to be interested in reducing actual pollutants as opposed to their targeted faux pollutant, “carbon”, but it’s a sham. The net effect of their very own anti-carbon policies has been to increase actual pollutants, and that effect will only increase unless they are shut down.
John Marshall said November 14, 2011 at 1:30 am
quote
Not mentioned is the major source of aerosols- the ocean’s surface. But that would be omitted because fossil fuel burning is their target.
unquote
Just imagine what would happen if we could find a way of supressing the production of salt cloud condensation nuclei from the ocean’s surface. Even a minor reduction would have major warming effects, first on the sea temps and then — because there’s a paper which measured this and found that land temps follow sea temps — land warming.
Of course you wouldn’t get the tropospheric warming signal. And cloud cover reductions would occur.
Hmm. Surely there must be somethng that we could put on the oceans which would spread out to molecule-thin layers and do this. Ideas? Anyone?
JF
@ur momisugly Joe: We have to get past this singular idea of governmental regulation being strictly the actions and desires of government. The real issue is not government versus the rest of us. The real issue is big government and big business in combination (call it crony capitalism) versus small business and individuals and what this combination of the “bigs” does to small business and individuals. We need to think of this issue in terms of big versus small, not in terms of government versus everyone else, or in terms of left versus right.
Most of what we call “excessive regulation” is the product of big business lobbying the “bought” politicians to regulate small business and individuals who can’t afford regulatory compliance. This kind of regulation puts small businesses and individuals out of business and leads to monopolies. Most “excessive regulation” is intentionally designed by big businesses who can afford the costs of regulation and take advantage of the costs of regulation. It gives big business plausible denial and the right to complain about government as well (while being secretly in support of it). Big business is really behind excessive regulation. Why? Big business can cope with the costs of regulation (and therefore imposes these costs on everyone who can’t) to force small business and individuals, who can’t cope with the costs, out of business.
The global warming scare is just a variation on the same old scheme of crony capitalism. Big business will gladly do whatever big governments require in terms of cutting CO2, as long as governments make cutting CO2 very expensive on the little guys. Publicly big business complains, but privately big business enjoys another monopolistic ploy.
@ur momisugly DirkH. I am sure that lots of scientists complain, but their complaints sound hollow when they get paychecks from either government or from big business, both of which have vested interests in the outcome of scientific work. It is the appearance of impropriety due to the fact they are getting paid by an entity that has vested interests in the outcome of the scientific work. They just look like paid whores.
If scientists want to appear to have integrity and neutrality, scientists have to get off the government tit, and/or off the big business tit.
” Different processes may work in harmony to offset each other , leading to a complex yet inconclusive interpretation of their long-term net effect . ” Well , that pretty much sums it up , doesn’t it ? Also , the last I heard , GHGs don’t prevent absorbed energy from being radiated as heat back into space , the key word being prevent . This is rubbish .
The graphic which accompanies the news release includes a cloud labeled as “Storm” (upper right corner). I believe that is actually an image of a volcanic eruption, not a storm cloud.
Tell you what though, those thinking the air is bad these days would be shocked to see what it was like in the 50s and 60s.
John says:
November 14, 2011 at 6:20 am
This may be a perfectly accurate study, but it seems to me that the normal and appropriate skepticism – in the best sense of the word, waiting to see if there is confirmation by other groups using somewhat different methods – is somewhat missing here.
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You get numb to this crap after awhile.
It is not the study of rain vs aerosols that is the problem, it is the attempt to lay blame on humans when there are plenty of other sources of aerosols besides humans. It is also the “Computer Model SAYS” that is another big turn off.
As Mothusi Songa told The Botswana Gazette “Don’t you know that scientists lie a lot to make money?”
That growing attitude is the fallout from dishonest climate scientists. Scientists have broken faith with those who foot the bills and by continuing to write statements like:
Where “sustainable development” is the code word for the United Nations Agenda 21.
Do not expect people to take this “Science” as anything but Political SPIN no matter how good the actual “science” may be.
It is Political Agenda driven “Science” no different than the crud churned out by Trofim Denisovich Lysenko.
“Increases in manufacturing, building of power plants and other industrial developments are often accompanied with increases in pollution whose adverse impacts on weather and climate, as revealed in this study, can undercut economic gains,” Zhanqing Li
It seems to me the take-away of this article is that we should never have survived the industrial revolution. All the drier areas should have turned to dust and blown away, and all the rainy areas should have flooded and washed away. Given that industrial development and building power plants has been causing such diminishing returns, I’d really like to know what has counteracted it? Anybody know? Why does industrialization still make people rich rather than kill us?
I also note that much of the data is from Oklahoma. The University of Oklahoma has one of the preeminent research facilities for such, and our local news has some of the best meteorologists in the world (except maybe for Chico). 😉 It strikes me that no Oklahoman’s are listed. Who knows our weather better than us? I also find it noteworthy that the 1930s are still the worst era for the south-central plains. We have also had worse floods in the past.
Mainly, as I said above and others commented also, 10 years of data? Give me a break.
I have an example of limited data. I did a lot of Charpy impact testing some years back, and that is a mess of a test. Hundreds of data points are required to minimize uncertainty for a complete transition curve. So how was I able to determine the curve from as few as five data points? First, the confidence was low with so little data, but 10-12 data points gave confidence under most circumstances. The key is that metals are well behaved, and prior knowledge of the material being tested can give you a very good guess before you begin. If you can hit the upper shelf, lower shelf, and somewhere on the transition with your first three or four samples, you can increase confidence with the remaining samples. Of course, if you miss and cannot define at least one point on each of the three regions before you run out of equivalent samples, then you are SOL. That set is a bust. You through that curve out and admit the error. We even developed finite element models, and these worked well, but so much had to be known before you could run the programs. The models helped extend knowledge. They could not create it.
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Mike Smith says:
November 14, 2011 at 7:09 am
Well, there a lots of reasons to support reductions in particulate pollution that have nothing to do with climate. The adverse impact of particulate pollution on human health is large and well established.
We can’t do much about the production of volcanic ash but there are good reasons to reduce avoidable soot and other discharges in populated areas. Smog, asthma, and lung disease are not pleasant for anyone…..
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The EPA is right on it. They are looking at regulating farm dust and the DOT is planning on reclassifying farm equipment so all farmers and workers must have commercial drivers licenses and comply with all the paperwork.
I really need to get my greenhouse built….
Mike Jonas, please define “that”.
OK, no joke, are we to die to give the models a chance?
The main purpose of this whole (or holed) study is to give an “explanation” for the failure of the IPCC predictions. They will say “we were right about warming from carbon dioxide, but aerosols operate in the reverse direction reducing the apparent impact”.
Saves face, and keeps the whole scare (and money supply) going for a few more years.
Holy cow a study based on 10 whole years of data, and a computer model of clouds when we don’t even know if clouds have a cooling or warming effect, I sure there is no way this study could be wrong.
The study is one of many built on field studies under NASA, NOAA and the NSF since 2004. The most important was the Maldives Autonomous Campaign (MAC), a field study of the contribution of light-absorbing and light-scattering aerosols in atmospheric brown clouds (ABCs) to atmospheric solar heating and surface cooling on a synoptic scale.
In 2007 Ramanathan reported (Nature 448, 575–578):-
“… the recently observed widespread occurrence of vertically extended atmospheric brown clouds over the Indian Ocean and Asia, suggest that atmospheric brown clouds contribute as much as the recent increase in anthropogenic greenhouse gases to regional lower atmospheric warming trends.”
“We propose that the combined warming trend of 0.25K per decade may be sufficient to account for the observed retreat of the Himalayan glaciers.”
NASA intended to follow up using a aerosol polarimeter sensor on the Glory Mission, but this was frustrated by the launch failure.
I found a link that gives quantification of the effects
The study found that under very dirty conditions, the mean cloud height of deep convective clouds is more than twice the mean height under crystal clean air conditions. “The probability of heavy rain is virtually doubled from clean to dirty conditions, while the chance of light rain is reduced by 50 percent,” says Maryland’s Li, who is also affiliated with Beijing Normal University.
http://www.sciencedaily.com/releases/2011/11/111113141304.htm
These are large effects. While, the effects themselves don’t surprise me, the size does.
FWIIW, I think this and similar aerosol studies are taking us closer to the point where the 0.7C rise in land surface temperatures since 1970 will be recognized as primarily an aerosol and aerosol seeded cloud effect, with GHGs playing a secondary role.
Tim Ball has just about nailed it. As to particulates let me see, oh yes, smoke and clouds oh yes reflectors or maybe not. That translates to smoke and mirrors. That equates to politicians not scientists or maybe it is scientists studying, modeling if you will, being politicians.
About the Dust Bowl, there was rain, snow and even floods. In the winter and spring.
Volcanic activity was way above normal. But you cannot prove it now with the Global Volcanism Program because they have cut the numbers of both the volcano counts and VEI by a substantial amount. Nearly in half for some years in that decade.
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And here I thought that the cleaning up of the atmosphere that occurred over the last few decades was allowing more sunlight through and causing warming!
“”””” Rising air pollution worsens drought, “””””
Izzat “rising” air pollution; of maybe “increasing” air pollution ??
Why would it matter whether the pollution rises, or falls to the ground, like acid rain for example ??
Two comments. First, anything related to climate change coming from the University of Maryland is highly suspect, given their dependence on State funding. The Maryland Governor’s “green” initiatives practically ensure any study done by this university will be AGW alarmist in nature. Second, if these aerosols do cause what this study claims, then there should be some real exciting weather downwind (that is East, for the most part) of China and India. Is there?