From the University of Manchester
Organic vapors affect clouds leading to previously unidentified climate cooling
University of Manchester scientists, writing in the journal Nature Geoscience, have shown that natural emissions and manmade pollutants can both have an unexpected cooling effect on the world’s climate by making clouds brighter.
Clouds are made of water droplets, condensed on to tiny particles suspended in the air. When the air is humid enough, the particles swell into cloud droplets. It has been known for some decades that the number of these particles and their size control how bright the clouds appear from the top, controlling the efficiency with which clouds scatter sunlight back into space. A major challenge for climate science is to understand and quantify these effects which have a major impact in polluted regions.
The tiny seed particles can either be natural (for example, sea spray or dust) or manmade pollutants (from vehicle exhausts or industrial activity). These particles often contain a large amount of organic material and these compounds are quite volatile, so in warm conditions exist as a vapour (in much the same way as a perfume is liquid but gives off an aroma when it evaporates on warm skin).
The researchers found that the effect acts in reverse in the atmosphere as volatile organic compounds from pollution or from the biosphere evaporate and give off characteristic aromas, such as the pine smells from forest, but under moist cooler conditions where clouds form, the molecules prefer to be liquid and make larger particles that are more effective seeds for cloud droplets.
“We discovered that organic compounds such as those formed from forest emissions or from vehicle exhaust, affect the number of droplets in a cloud and hence its brightness, so affecting climate,” said study author Professor Gordon McFiggans, from the University of Manchester’s School of Earth, Atmospheric and Environmental Sciences.
“We developed a model and made predictions of a substantially enhanced number of cloud droplets from an atmospherically reasonable amount of organic gases.
“More cloud droplets lead to brighter cloud when viewed from above, reflecting more incoming sunlight. We did some calculations of the effects on climate and found that the cooling effect on global climate of the increase in cloud seed effectiveness is at least as great as the previously found entire uncertainty in the effect of pollution on clouds.”
The paper:
Nature Geoscience paper, ‘Cloud droplet number enhanced by co-condensation of organic papers,’ by Gordon McFiggans et al,
Since there are several comments that disparage the paper I felt compelled to go look for myself.
I recommend that in every case. Thinking for yourself is almost as entertaining as reading WUWT.
This one is not behind a paywall and looks to be a sincere and substantial effort.
My understanding of it, and I am much too dumb to understand it all, is that they used actual droplet measurements taken by others and applied their minds and all of the associated previously compiled methods and models in examining this topic to understand The effect of physical and chemical aerosol properties on warm cloud droplet activation.
I am prepared to accept that this is not your typical fawning CAGW must-get-into-AR5 rent seeking paper and should be assumed to be a serious examination of the topic that is actually relevant and important to our shared interest in the real influences of our climate.
Niff, It probably is definitely scholarly. Scientific papers should be. I have not read it yet, but my impression is it provides a description of the mechanism between aerosols and cloud formation. My understanding is this is not a “new” global cooling mechanism, and has been known for a while. A physical connection is described but the mechanism is not new. So…saying something is new is not equivalent to AGW refutation. Now I have to actually go read it even if it costs some bucks.
“We discovered that organic compounds such as those formed from forest emissions or from vehicle exhaust, affect the number of droplets in a cloud and hence its brightness, so affecting climate,” said study author Professor Gordon McFiggans, from the University of Manchester’s School of Earth, Atmospheric and Environmental Sciences.
That statement was remarkably evenhanded. I wonder if this reflects the start of academia’s step back from global warming?
This kind of paper is part of the “turning around” that we will see more of in climate science. Once again, seeing the flat-lining and decline of global temps, these guys won’t say we were wrong, they say the CO2 Armageddon has been “masked” by the cooling from forest vapours and MAN MADE POLLUTANTS. Having recorded that the planet has been greening significantly and forests growing more robust and into deserts – surely if org vapours are the cause, it must be mainly natural – wow what a big negative feedback this is. The auto exhaust is CO2 and water vapour (virtually all vehicles have catalytic converters) – this is not organic vapours that can form “perfume” droplets.
If Cook’s survey of the climate science industry doesn’t show the 97% having eroded significantly post climategate, then that is itself proof of statistical fabrication. Even Hansen is going “cool”, Trenberth is not very wholeheartedly looking for the “missing heat” – more like OJ looking for Nicole’s killer- and it was Phil Jones after the climategate deflated his world that was the first to point out that there had been no statistical warming for about 15 yrs, which tripped the bold step of Hadley folk to say we were going to be cooling through 2017. Watch for the U of Washington State, Colorado Boulder, and some others to come out with getting-colder-papers.
Except when it isn’t all peaches and cream. Ya know, like glacials, which has been the norm for a couple million years or so I think. And of course all the wild ups and downs which have occurred over billions of years. You’re making the same mistake as “climatologists”, only looking at a teeny tiny snapshot in time where things are relatively stable and favorable to humans.
It’s called Global Dimming! LOL!
And it’s been a while since we had a good Pinutubo or St. Helens sized explosion. We’re way overdue. We’re even overdue for a Mazama or a Long Valley/Bishop.
I think he means the IPCC’s positive feedback from more water vapor.
Roger Knights says:
May 6, 2013 at 8:21 pm
“I think he means the IPCC’s positive feedback from more water vapor.”
Roger, the IPCC didn’t say 60% of AGW warming would be from the “…formation and behavior of clouds…” And given that nearly (ex.: sublimation) all cloud formation involves water vapor, GlenMohr’s statement is patently false. JP
“I wonder if this reflects the start of academia’s step back from global warming?” [Katherine @ur momisugly 1911 on 5/6/13]
It appears to me that it is simply the Cult of Climatology’s way of continuing to say that humans cause climate change (yes, indeed, “global warming” is passé). Carbon-based gases are causing the cooling, therefore, any human carbon-emitting activity is causing cooling (which is, of course, will cause an IMMINENT CATASTROPHE). It’s illogical and inconsistent (last week year, the planet was still on it’s way to boiling because of human CO2, LOL), but, for the Cult, it isn’t about truth; it’s PURELY PROPAGANDA to bolster their crumbling AGW empire (regulatory domination of economy and of our freedom in general).
Yes, there is a real cloud reflection mechanism AND they are exploiting it by mischaracterizing the cause-effect of human emitted CO2. AGAIN.
Gary Pearse says:
May 6, 2013 at 7:22 pm
“..these guys won’t say we were wrong, they say the CO2 Armageddon has been “masked”… “
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Bingo!
These are the last days for AGW. The full on squealing panic has begun. The believers are desperately scrabbling to find an exit. They want to come up with a “masking” effect so the embarrassing flaw in the “CO2 warms” claims are not exposed. They also want it to sound suitably ”sciencey” so they don’t look like complete idiots for previously missing it. But none of this is going to work.
Radiative gases are critical for atmospheric cooling and convective circulation below the tropopause. The original AGW calculations are based on treating the atmosphere as a static body or layer, essentially a two shell model. This gives the wrong answer for an atmosphere in which the gases are free to move. For a moving atmosphere the net effect of adding radiative gases is cooling at all concentrations above 0.0ppm. The mistake in the basic calculations is recorded forever on the Internet.
http://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=MODAL2_M_CLD_FR
Only trend i can see is less cloud cover in the Arctic; i think
Catalytic converters mandated in the USA and Canada in 1976, and much of the rest of the world soon after, remove volatile organic compounds from vehicle exhausts.
That surface warming and global cloud decreases start at this time is no coincidence.
I am amazed at how many new “cooling” effects are suddenly being found. Seems every time I turn around there is a newly discovered “cooling” effect. Perhaps it is as simple as “there is no GHE” ? … Perhaps Achems Razor is applicable here?
REPLY: Occams Razor, and yes there is a GHE. Get over yourself, and note that we have a policy on this sot of “slayer” arguments thread bombing. – Anthony
What I want to know is how there can be any new discoveries or reasons why the predictions are wrong as the science was reported to be settled and beyond question. Clearly they lied.
squid2112 says:
May 6, 2013 at 10:57 pm
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Yes, there is a radiative GHE. Radiative gases in the atmosphere do keep the land surface warmer at night than it would otherwise be. However radiative gases also play a critical role in tropospheric convective circulation and atmospheric cooling. The question is the net effect of radiative gases in out atmosphere.
If I said –
“Initially adding radiative gases to the atmosphere causes cooling, but after a certain magical point which strangely coincides with current political conditions these gases cause warming.”
– would you believe it? No? Well that argument is what is currently propping up the AGW hypothesis.
David Cage says:
May 6, 2013 at 11:53 pm
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No, first they made a mistake. By the time they found the problem too many people had joined the cause to organise a painless back down. Then they lied.
Dave Wendt says:
May 6, 2013 at 1:25 pm
Your post reminds me of the “super chimney” idea. It is well known that if you can isolate a tall column of air and stop it mixing with the adjacent air (in other words make a “chimney”) and open it up at the bottom then the temperature difference between the air at the bottom and the top will cause the air in the chimney to rise, drawing in at the bottom and expelling at the top.
The higher the chimney the greater the temperature difference and the faster the air movement. It has been hypothesized that if you could build a chimney a mile high that you could fit turbines at the bottom where the air is drawn in and generate electricity. The most interesting bit is the main side effect which is the formation of clouds at the top where the warm air with a high moisture content hits the cold air a mile up and condenses. This quickly precipitates out as rain. In fact this is the same thing seen when prevailing winds strike a mountain range causing an updraft and rain cloud formation.
The best place to stick one of these chimneys would be in a desert area where the daytime temperatures are high. This would generate a lot of cloud cover (increasing albedo) and the rain would irrigate the desert which could be used for food production or forestry.
It seems to me such an obvious and brilliant idea that I am surprised nobody has built one yet. One guy has put up a web site explaining the idea.
http://www.superchimney.org/
TLM says:
May 7, 2013 at 1:42 am
“It seems to me such an obvious and brilliant idea that I am surprised nobody has built one yet”
It looks like the diminishing cost of PV kills the solar chimney technology, just like it kills solarthermal power plants:
Comparison of theoretical maximum efficiency of a solar chimney with PV:
“For perspective, PV panels providing the same amount of energy (assuming they operate at ~20%), would occupy 2.5% as much land.”
from
http://en.wikipedia.org/wiki/Solar_updraft_tower
atarsinc says:
May 6, 2013 at 4:13 pm
Clouds are inextricably linked to water vapor. Without either, it would be about -16^C. JP
Depends on the resulting albedo and the greenhouse affect of co2, ozone, oxygen, nitrogen.
Wikipedia says “water is usually considered to have a very low albedo”.
The moon has an albedo of 0.14, so use that.
Sun at zenith is 1004 W/m2. Plugging that into Stefan-Boltzmann, I get 260K, near your figure.
However if a GHG figure of 0.3 absorbed and 0.7 passed is used (guesstimate from eye-balling graphs), then ((1004 W/m2 * 0.25 / 0.7) /sigma ) ** 0.25 gives me 284K, about current global surface temperature. But this temperature is not the surface temperature. It is the temperature in the upper atmosphere in thermal equilibrium. The surface would be warmer. So clouds cool.
richard telford says:
May 6, 2013 at 12:24 pm
Of course, if the pollution-induced changes in albedo are greater than previously thought, more of the CO2-induced warming has been masked, and you can kiss goodbye to your low climate sensitivity
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That doesn’t follow. The Clean Air Act passed in many industrial countries coincides with the period of unexplained warming attributed to CO2 (1970’s onward). The entire warming might thus be a result of reduced pollution and the CO2 sensitivity may in fact be zero or even negative.
Algae, by far the most abundant life form on earth has co-evolve with the atmosphere and the clouds. For hundreds of millions of years Algae has maintained the earth’s temperature at 16C +- 5C, by regulating the clouds and thus ensuring its own continued survival. This is accomplished by the organic compounds that Algae releases to the atmosphere in response to increased and decreased sunlight.
We do not control the climate on planet Earth. Algae does. It maintains the temperature and the oxygen levels necessary for our continued survival. We are simply spectators. The flea on the elephants back that thinks it controls the elephant.
More correctly, Algae have maintained the earth’s average surface temperature at 290K +- 5K for hundreds of millions of years. A variance of less than 2% over hundreds of millions of years. Something that is well beyond the capability of any human technology ever dreamed of.
I do so hate it when commenters dismiss work as just another attempt to jump aboard an academic gravy-train. Ouch! Have you looked at the paper? Fifty-odd pages of closely-worked theory, observations, and joint-effect approaches ranging from mass spectroscopy to the surface tension of fog (!) – to say nothing of sundry heavy-weight formulae etc. Give them a fair wind, please.
My judgement is, of course, entirely unclouded by the fact that, as a Mancunian, I am proud of the work of my alma mater and of her learned profs.
Dave Wendt says:
May 6, 2013 at 1:25 pm
Irrigated afforestation of the Sahara and Australian Outback to end global warming
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irrigation may not be sufficient. often sand dunes are held in place by ground water underneath the sand. the motion of the sand in the wind smothers the plants.
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richard telford says:
May 6, 2013 at 12:24 pm
Of course, if the pollution-induced changes in albedo are greater than previously thought, more of the CO2-induced warming has been masked, and you can kiss goodbye to your low climate sensitivity.
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Funny thing is, I’m downwind of the Ohio Valley in the Appalachians where all the evil coal plants are, and visibility here is at least as good as it was a century ago, according to observations — 60 miles plus on clear days any time of the yr other than summer (when haze is produced by leafed-out forests). From a high elevation on such days I see clearly see the Blue Ridge mountains over 65 miles to the east. Yeah, pollution controls have alot to do w/this, but that’s the point — the goal is already accomplished, other than big cities.
Man-made haze is a localized effect, not remotely global.