From a Press Release from the Max Planck Institute for Meteorology
Do dust particles curb climate change?
A knowledge gap exists in the area of climate research: for decades, scientists have been asking themselves whether, and to what extent man-made aerosols, that is, dust particles suspended in the atmosphere, enlarge the cloud cover and thus curb climate warming. Research has made little or no progress on this issue. Two scientists from the Max Planck Institute for Meteorology in Hamburg (MPI-M) and the American National Oceanic and Atmospheric Administration (NOAA) report in the journal Nature that the interaction between aerosols, clouds and precipitation is strongly dependent on factors that have not been adequately researched up to now. They urge the adoption of a research concept that will close this gap in the knowledge. (Nature, October 1st, 2009)
Greenhouse gases that heat up the earth’s atmosphere have their adversaries: dust particles suspended in the atmosphere which are known as aerosols. They arise naturally, for example when wind blows up desert dust, and through human activities. A large proportion of the man-made aerosols arise from sulfur dioxides that are generated, in turn, by the combustion of fossil fuels.
The aerosols are viewed as climate coolers, which compensate in part for the heating up of the earth by greenhouse gases. Climate researchers imagine the workings of this cooling mechanism in very simple terms: when aerosols penetrate clouds, they attract water molecules and therefore act as condensation seeds for drops of water. The more aerosol particles suspended in the cloud, the more drops of water are formed. When man-made dust particles join the natural ones, the number of drops increases. As a result, the average size of the drops decreases. Because smaller drops do not fall to the ground, the aerosols prevent the cloud from raining out and extend its lifetime. Consequently, the cloud cover over the earth’s surface increases. Because clouds reflect the solar radiation and throw it back into space, less heat collects in the atmosphere than when the sky is clear. Climate researchers refer to this mechanism as the “cloud lifetime effect”.
To date, however, it has not been possible to quantify the influence of the cloud lifetime effect on climate. The estimates vary hugely and range from no influence whatsoever to a cooling effect that is sufficient to more than compensate for the heating effect of carbon dioxide.
According to Bjorn Stevens from the MPI-M and Graham Feingold from the Earth System Research Laboratory at NOAA in Washington D.C the enormous uncertainty surrounding this phenomenon is indicative of the fact that the explanation of the cooling mechanism generated by aerosols is oversimplified. The two cloud researchers have analyzed the specialist literature published on this topic since the 1970s. In their survey of the literature they encountered observations that disagree with the cloud lifetime effect: for example, a field study carried out a few years ago found that clouds in the Trade Wind region rain out more quickly rather than more slowly in the presence of virtually opaque aerosols.
On the completion of their analysis of the literature, Stevens and Feingold came to the following conclusion: “Clouds react to aerosols in a very complex way and the reaction is strongly dependent on the type and state of the cloud,” says Stevens. Therefore the aerosol problem is a cloud problem. “We climate researchers must focus more on cloud systems and understand them better,” he stresses.
As the researchers write, processes in the clouds that counteract or even negate the influence of the aerosol particles have not been taken into account up to now. One example: when a cumulus cloud comes into contact with aerosols, it does not rain out. However, this has certain consequences: the fluid rises and evaporates above the cloud. The air that lies above the cloud cools down and becomes susceptible to the upward extension of the cumulus cloud. Higher cumulus clouds rain out more easily than lower ones. This is what causes precipitation. Therefore, in such situations the aerosol does not prevent the cloud from raining out.
Stevens and Feingold believe that due to such buffer mechanisms the cooling effect of the aerosols is likely to be minimal. They admit, however, that the cloud lifetime effect is not unsuitable per se as a way of explaining the processes triggered by aerosols in the clouds. “All cloud types and states cannot, however, be lumped together,” says Stevens. He calls for rethinking aerosol research and makes a comparison with cancer research: “People used to think that cancer was based on a single mechanism. Today, it is known that each type of cancer must be researched individually,” says the scientist.
According to Stevens and Feingold, research must first identify the cloud systems on which aerosols have the greatest influence. They suggest starting with particularly common types of cloud, for example flat cumulus clouds over the oceans (Trade Wind cumuli), which cover 40 percent of the global seas.
A research project to be undertaken jointly by the Max Planck Institute for Meteorology and the Caribbean Institute for Meteorology and Hydrology in Miami will make a start on this. The two-year empirical field study will commence on the Caribbean island of Barbados, which is located in the Trade Wind region, in 2010. The researchers will install remote sensing instruments on the island’s windward side that will focus on the clouds coming from the open ocean. The land measurements will be complemented by measurements taken in the clouds themselves by HALO, the German research aircraft. The data from this measurement campaign should help the scientists to reach a better understanding of the relationships between cloud cover, precipitation, local meteorological conditions and aerosols.
Related links:
[1] Aerosols, Clouds, Precipitation and Climate: Barbados Field Study
[2] HALO Website (The High Altitude and LOng Range Research Aircraft)
Original work:
Bjorn Stevens, Graham Feingold
Untangling aerosol effects on clouds and precipitation in a buffered system
Nature, October 1st 2009, Volume 461, pages 607 – 613
OT
Happy days are here again. What a relief. I was led to believe the planet was going to go up in a fiery ball of flames, and it was all my fault.
Antarctic Ice Melt at Lowest Levels in Satellite Era
http://www.worldclimatereport.com/index.php/2009/10/06/antarctic-ice-melt-at-lowest-levels-in-satellite-era/
I must confess I made it up; excuse me while I catch my breath.
I suppose I should be happy that some scientists are finally admitting climate is more complex then they thought. However I am saddened at the slant of “to see how much this is masking global warming”. I mean from as far as we know except for the minuscule warming that SHOULD occur with CO2 there has been no real warming at all.
I suppose that is where the media, and maybe even most other ‘science’ blogs get skeptics wrong. It is not that we do not believe that CO2 will warm the atmosphere. It is the preposterous levels that are claimed that leave us slack-jawed from shock ( I am using the royal we here – I suppose it is really simply myself that feels this way but I feel so much better saying we )
It is not that an increase in CO2 does not ‘warm’ the atmosphere, but rather a question of the silly feedback mechanisms that have been used to ‘predict’ large amounts of warming, rather then looking for other possible climactic causes. Just the fact that the almost linear progression of CO2 has not even come close to matching up to the temperature increase to data ( CO2 steady climb, temperature not so much I mean if we were in the 70’s we would be asking if CO2 had a negative impact on temperature somehow lol )
That is again not to say that CO2 could not be a catalyst for runaway warming, but… it is pretty theoretical at this point since it hasn’t happened. I am tired of reading stories like “unless something is done about CO2 the temperature COULD increase as much as 2 degrees Celsius by 2050. Does not Could imply that it may do nothing of the sort? Could it not also not change?
Sorry if this is a rant, this article managed to make me feel tired of saying the same thing over and over again. I am tired of science being something you advocate rather then study. I am thankful to everyone out there who rather then be silenced by the majority ( the consensus ) is still researching and asking questions other then, how much higher can we say the temperature will go? If in the end the ‘consensus’ is right we will know not because they told us, but because we proved it… but at this time the truth is still out there buried in a million different places.
Innocentious (21:23:00) :”I am tired of science being something you advocate rather than
study. “
“If in the end the ‘consensus’ is right we will know not because they told us, but because we proved it… but at this time the truth is still out there buried in a million different places.”
Hear hear!
Chris
Norfolk, VA, USA
I sat on a hillside
and gazed up at the clouds
while others were acting
like they were not around
they made a few models
showing temperatures up
and blaming emissions
for the increase of heat
then it grew stormy
I am sorry to say
and all of that heat
simply went away
clouds it would seem
play a pretty big role
in temperature regulation
don’t you know
Sometimes human beings just don’t like being told everything under the Sun is their fault. Human beings with a spine may rebel at that notion. It only took 12% of the original colonists with a backbone to form the greatest nation on Earth.
It is reaaally amazing to see so many issues popping up one after another in the sacrosanct “Debate is Over” Science.
I feel past volcanic events have provided evidence that aerosol particulates can cause cooling, whether through global dimming or cloud nucleation. While anthropogenic additions to aerosol particulates may be small compared to natural sources, they are more of a concern than CO2. The last thing we need in the next decades is more cooling.
Improvements in air quality in developed nations over the past few decades shows that we can do a lot to decrease anthropogenic aerosol particulates. More could be achieved with regard to surface transport such as ships, trains and trucks. The problem may be getting people to care.
So many people have been crying Wolf on CO2 so loud and for so long… Based on studies of twelve hairs we found the size of the wolf is unprecedented…The planet could be sheep free in less than a decade…It’s more bitey than we thought…and the rest. Will anyone be interested in aerosol particulates?
I feel there may be good reason to study the impact of aerosol particulates. Creating an excuse that CO2 warming has been “masked” but is still a huge threat would not be among them.
Well, have a look at this flash back
http://www.wnd.com/?pageId=112073
WND has obtained a copy of a college textbook Holdren co-edited with Malthusian population alarmist Paul R. Ehrlich in 1971, entitled “Global Ecology,” now a rare out-of-print book that cost WND over $100 to buy on Amazon.
Warning the world was headed for a new ice age unless the government mandated urgent measures to control population, including the possibility of involuntary birth control measures such as forced sterilizations, Holdren predicted “ecocide” or the “destruction of all life on this planet” were a possible consequence of inaction.
In an essay contained in the textbook entitled “Overpopulation and the Potential for Ecocide,” Holden and Ehrlich predicted on pages 76-77 a “world cooling trend” they estimated at measuring “about 2 degrees Celsius in the world mean surface temperature over the past century.”
Holdren and Ehrlich attributed the cause of global cooling to “a reduced transparency of the atmosphere to incoming light as a result of urban air pollutions (smoke, aerosols), agriculture air pollution (dust), and volcanic oil.” (Parenthesis in original text.)
The authors worried “a mere 1 percent increase in low cloud cover would decrease the surface temperature by .8C” and that “a decrease of 4C would probably be sufficient to cause another ice age.”
Holdren and Ehrlich warned, “The effects of a new ice age on agriculture and the supportability of large populations scarcely need elaboration here.”
They continued: “Even more dramatic results are possible, however; for instance, a sudden outward slumping in the Antarctic ice cap, induced by added weight, could generate a tidal wave of proportions unprecedented in recorded history.”
Even a stopped clock is accurate twice a day, coming and going.
FYI: A photo (high resolution) of a dust storm in Easthern Washington State (Sun., Oct. 4th) is here:
http://earthobservatory.nasa.gov/images/imagerecords/40000/40590/wash_TMO_2009277_lrg.jpg
State boundaries appear as light gray lines. Dust is the light brown under the white cloud.
A simple news story and a photo with a locator town is here:
http://www.komonews.com/weather/blog/63562137.html
Re Anna V on Holdren & Ehrlic
Some of us are old enough to remember reading that; and Nigel Calder’s “Weather Machine”. I still have my copy of the latter. That’s one of the reasons so many of us sceptics (and lukewarmers) are so much older than the warmers. We don’t swallow the BS. We’ve heard it all before.
Personally, when I read some alarmist drivel I run around in a circle flapping my hands and chanting: “wibble, wibble, wibble”. Then I have a nice cold glass of Marlborough district sauvignon blanc and feel much better 🙂
“Greenhouse gases that heat up the earth’s atmosphere”. I thought it was the energy from the sun that was responsible. If I put a greenhouse gas into my house, will it heat up the house’s atmosphere and will I be able to turn down my heating system and save energy and money?
[youtube=http://www.youtube.com/watch?v=6vTJ0lNY54E&hl=en&fs=1&]
Well, if kim’s allowed to repeat himself:
The oceans produce salt particles which become CCNs.
Man makes dust/smoke which becomes CCNs.
http://seawifs.gsfc.nasa.gov/OCEAN_PLANET/HTML/peril_oil_pollution.html shows us a mechanism whereby Man can reduce the amount of oceanic CCNs. (Briefly: 363 million gallons of oil spills down the drain each year; 5ml of oil will smooth a hectare of ocean surface; smoothed ocean reacts less with the wind and fewer breakers form — the loss of engagement is equivalent, I believe on the evidence of one set of wind data from WWII, to a reduction of windspeed of 7 m/s, but that’s very flakey; fewer salt particles, less cloud in the boundary layer, warmer ocean surface.) thus there is a conflict between sea surface pollution and atmospheric pollution. From 1946 to 1970 we made more sulphur etc CCNs than we suppressed salt CCNs. It cooled. Before and after those dates our oil spills predominated in their climate effects. Spill less oil and the world will cool.
For the hypothesis: global warming starts in 1850, well before CO2 can have been the cause, and the warming rate from 1910 to 1940 (CO2 forcing .25w/m^2) is the same as from 1970 to 2000 (CO2 forcing 2 w/m^2); there is an enormous hump in temp from 1940 to 46 — raw data — which is hidden when the Folland and Parker bucket correction is phased in; polar ice melting is concentrated in areas where oil spills are to be expected. Large oil spills clear cloud downwind.
Against: the big Mexican oil spill doesn’t show any effect.
:Lindzen doesn’t think the effect is big enough.
: no-one’s done the research.
Google for “the last polar bear” image and look at the sea surface behind the poor little bear on his tiny square floe. All the surface is smoothed, but long lines of extra pollution show as lighter areas.
I leave the effect of smoothed surfaces on the rate of uptake of heat during the day (hint, albedo goes down) and the rate of heat loss at night (hint, emissivity goes down) to the keen student.
kim, there was a line from a poem that the chap who did the last page in Flight used to quote, but it’s not on the web. ‘And suddenly a cloud took all away’. If science begins to look at clouds, finds that the science is far from being settled and is all tosh, it could be a very apt line.
JF
Sorry to comment to an OT, but I couldn’t help myself. In response to:
____________________________
“OT
Happy days are here again. What a relief. I was led to believe the planet was going to go up in a fiery ball of flames, and it was all my fault.
Antarctic Ice Melt at Lowest Levels in Satellite Era
http://www.worldclimatereport.com/index.php/2009/10/06/antarctic-ice-melt-at-lowest-levels-in-satellite-era/”
—————————–
It still will not stop the media recycling that picture of a dirty great crack along the ice shelf and telling us that when it breaks off (again) that it is a unique and dangerous proof of evil selfish motorists killing those cute and fluffy white polar bears.
They cannot allow the truth to get in the way of good propaganda.
The two-year empirical field study will commence on the Caribbean island of Barbados, which is located in the Trade Wind region, in 2010.
Nice work if you can get it.
Thanks for the link M. Simon. We sailplane pilots spend much of our time looking up at cumulus clouds but every now and again after a climb to cloudbase, if conditions are just right and you push out into wind, things suddenly go smooth and you get a magic carpet ride up the side of a cumulus and maybe well above its top. *Then* we look at clouds from both sides.
These guys want to know about forests so they study one verity of trees. Maybe they are near sighted.
And so the begging for new funds for more climate research continues. Them scientist know how to keep on pouring in more tax payers money…
Innocentious (21:23:00) :
You state my position pretty well, but That is again not to say that CO2 could not be a catalyst for runaway warming, is an unnecessary caution. CO2 has been much higher in times past and temperatures have not run away.
It seems that we get all tied up and sometimes fixated on each new hypothesis that comes along and purports to solve the questions on what and how the global climate is changed and “controlled” by some proposed feedback mechanism.
The CO2 hypothesis as the proposed global climate changing mechanism is a classic case of this fixation where unfortunately, for some totally inflexible proponents of this hypothesis, no alternative explanations will tolerated or considered at all.
Clouds and global cloud cover are currently getting a run amongst those who do not necessarily accept the CO2 hypothesis and on the face of it, the available evidence suggests that clouds seem to be the single most important feedback mechanism for the control of the global temperatures.
If the above is accepted, then by implication clouds and their associated feedback mechanisms control the global climate within very tight constraints and within a remarkably stable range of only a few percentage point changes in absolute temperature.
Lots and lots of questions remain about cloud cover effects which range all the way from low level cloud cover effects to Lindzen’s iris effect where high altitude equatorial clouds seem to cycle in their abilities to both trap and reflect infrared solar radiation.
Now the debate as above, is starting to switch to the way in which global and regional cloud cover is generated and the influences and factors involved in the changes in cloud cover.
The front runner for the mechanism involved in global cloud cover generation and control is Svensmark’s theory where a measured decline in solar magnetic fields is now allowing a greater influx of galactic cosmic rays to penetrate deep into the inner solar system and into the Earth’s upper atmosphere where collisions with upper atmospheric particles create a shower of cloud droplet nucleating particles which lead to greater cloud cover.
Lief’s comments from the latest WUWT posting above seems to question Svensmark’s theory as he points out the 10Be cosmic ray radionuclide counts don’t seem to be backing Svensmark’s theory.
Now we have this current posting on WUWT suggesting that aerosols may be very big contributors to the formation of cloud droplets.
This particular line of thought has been around for a long time and research in the past has shown that aerosols are indeed nucleating agents for cloud droplet formation and therefore play a big role in cloud formation.
However, that seems to leave out any known or guessed at feedback mechanism that would control the aerosol levels which in turn would control cloud formation and have a controlling effect on global climate.
Aerosols can be made up of inert particles such as silica and other mineral dust particles such as iron and etc.
Aerosols can also include chemical origin particles and biological particles such as bacteria, viruses and spores.
These latter two agents, in addition to the inert dust particles, are of biological origin and with the inert dust, are overlapping and interdependent.
The chemically based aerosols are isoprene and dimethyl sulphide, both of which are emitted by phytoplankton and are known to be involved in the process as a part of the cloud droplet nucleating agents.
There may be other chemicals, the research for which so far has not appeared for publication or has just been ignored as clouds don’t count with the climate modelers.
http://earthobservatory.nasa.gov/Newsroom/view.php?id=31349
The inert mineral dust in the overall aerosol group above quite likely plays a role in dramatically increasing the nutrients available to the phytoplankton and to other ocean life that also emits droplet nucleating chemicals.
The third factor in the known cloud droplet nucleating agents are bacteria, viruses and spores.
One of the ice nucleating bacteria which is also used to help snow making in the snow fields, causes a good deal of grief to a range of agricultural industries as the bacteria create ice on the leaves of plants at temperatures still just above freezing thus damaging the plant.
This species of bacteria, amongst many bacterial species, is often found in quite high concentrations in cloud droplets during high altitude air sampling flights and even in fog droplets over the hills of Scotland.
The Indians were shocked when they recently found 3 new species of very UV tolerant bacteria at some 10 to 50 kilometres up in a couple of upper atmosphere balloon sampling flights.
http://news.softpedia.com/news/Stratosphere-Reveals-New-Bacteria-107216.shtml
http://www.sciencedaily.com/releases/2009/03/090318094642.htm
My suggested feedback mechanism here is that the lower atmosphere origin bacteria / viruses / spores are all highly susceptible to the upper part of the UVC band which ranges from about 100nm to 280nm.
This UVC band is commonly used for germicidal control; ie; to help control bacterial infections.
It also penetrates deep into the lower atmospheric levels.
The UV bands are where the Sun has shown one of it’s largest decreases in activity with a 6% drop in UV levels during this solar minimum.
I think this is a satellite measurements but whether the measured solar UV levels are even lower at the lower atmospheric cloud levels during this solar minimum does not seem to have been checked.
The long term variations in the solar UV levels do not appear to be known with any real accuracy.
I would suggest that another additional mechanism for explaining the variations in global cloudiness could possibly be the changing solar UV levels and their impact on the biological cloud droplet nucleating agents and even on the ocean’s phytoplankton and thus on the phytoplankton’s
output of the cloud droplet nucleating isoprene and dimethyl sulphide chemicals.
Lower levels of solar UV output during this solar minimum, therefore higher survival levels of cloud droplet nucleating bacteria / viruses / spores and therefore increased cloud droplet formation and the consequent greater cloudiness and lower global temperatures.
And the reverse of course.
The whole question of cloud generation factors is a very complicated and interwoven and interdependent group of factors, some of which are probably not known or even guessed at for the moment.
It will take many years to disentangle the cloud effects whether large or minor on the global climate.
It will take even longer to disentangle which cloud forming factors are the most important and I suspect that these factors will be an ever changing morass in the way they shift and change according to the local conditions and influences on the cloud droplet nucleating agents.
I simply don’t believe the simplistic view that changes in global cloud formation can be explained by just one simple factor.
Nature is far more subtle, tricky and perverse than that!
I suggested the above bacterial cloud droplet nucleating agents scenario about a year ago in my first post on WUWT.
Not that I have done more than a handful of posts.
That first post was done with great trepidation as to a not very well educated, retired old farmer, the levels of knowledge displayed here by nearly all the regular posters is just simply beyond daunting in it’s range and quality.
Nothing has changed except the knowledge base and quality have become even more formidable to the average Joe and that makes it even more daunting to post on WUWT.
Clouds are described as having a cooling effect by reflecting the sunlight. However at night they have a very noticable insulating effect; the difference in temperature after a sunny day followed by a clear night is large.
Anthony –
Are keeping abreast of the CERN Cloud 9 experiment?
Powerpoint of Cloud 9
http://indico.cern.ch/getFile.py/access?resId=0&materialId=slides&confId=52576
IPCC concedes that clouds are poorly understood, then continues with their conclusions – remarkable to say the least.
Claude Harvey (19:08:05)
” I expect they will eventually “discover” that global temperature is fundamentally “self-correcting” by way of “negative feedbacks” to any forcing function that tries to change temperature.”
I’ve already ‘discovered’ that by suggesting that the negative feedbacks always work back towards a temperature equilibrium at the ocean/air interface and also ensure that energy leaving the Earth for space does not significantly exceed the energy reaching the Earth from the sun.
In each case components of the air circulation change as necessary in order to speed up or slow down the hydrological cycle which in turn alters the rate of energy transfer from surface to space so that those equilibria cannot be disturbed for long.
See my regular contributions to this site and my various articles here:
http://climaterealists.com/index.php?tid=37
I’m just waiting for the ‘professionals’ to catch up.
Chinook Winds dust storms in Eastern Washington state and the Idaho panhandle
John F. Hultquist (23:08:22) :
FYI: A photo (high resolution) of a dust storm in Easthern Washington State (Sun., Oct. 4th)
Your photo reminded me of a study I worked on in the early 1970s to quantify the type and amount of dust brought by Chinook wind storms. I was in northern Idaho at the time. As I recall, the hills in Eastern Washington were purported to have formed from dust and dirt dropped by the winds sweeping across the state. This was said to have created hills with as much as 60 feet depth of top soil.
The study was attempting to measure dust data from a Chinook dust storm. There were several air filters set up on rooftops in the area. (my job was to make daily rounds of these filters to gather the exposed filters and replace with fresh filter media) There were micropore filters, which captured particles down to very small size, and could be used to do microscopic particle analysis. Then there were larger ‘volume’ filters, with a calibrated air pump to pull air through a filter pad about 2 ft square, mounted in a shelter with louvered side openings, much like a Stevenson Screen.
We gathered data for weeks (months?) with no dust storm. Then when a storm came through, it was all we could do to keep up changing the volume filter media. Where previously a 24 hour cycle would bring a light coating of dust on a volume filter pad, during the storm we were changing the filters multiple times during the day, EACH WITH AN INCH OR TWO OF DIRT ON THE FILTER PAD. I never did see the resultant published paper (I was a grad student making some extra money running the rooftops), but I was pleased that we were able to get them some “Solid” data.