From the University of Michigan something I think Dr. Roy Spencer will be interested in as it is yet another case where models and satellite observations differ significantly. See the figure S1 at the end of this article – Anthony
Aerosols affect climate more than satellite estimates predict
ANN ARBOR, Mich.—Aerosol particles, including soot and sulfur dioxide from burning fossil fuels, essentially mask the effects of greenhouse gases and are at the heart of the biggest uncertainty in climate change prediction. New research from the University of Michigan shows that satellite-based projections of aerosols’ effect on Earth’s climate significantly underestimate their impacts.
The findings will be published online the week of Aug. 1 in the early edition of the Proceedings of the National Academy of Sciences.
Aerosols are at the core of “cloud drops”—water particles suspended in air that coalesce to form precipitation. Increasing the number of aerosol particles causes an increase in the number of cloud drops, which results in brighter clouds that reflect more light and have a greater cooling effect on the planet.
As to the extent of their cooling effect, scientists offer different scenarios that would raise the global average surface temperature during the next century between under 2 to over 3 degrees Celsius. That may not sound like a broad range, but it straddles the 2-degree tipping point beyond which scientists say the planet can expect more catastrophic climate change effects.
The satellite data that these findings poke holes in has been used to argue that all these models overestimate how hot the planet will get.
“The satellite estimates are way too small,” said Joyce Penner, the Ralph J. Cicerone Distinguished University Professor of Atmospheric Science. “There are things about the global model that should fit the satellite data but don’t, so I won’t argue that the models necessarily are correct. But we’ve explained why satellite estimates and the models are so different.”
Penner and her colleagues found faults in the techniques that satellite estimates use to find the difference between cloud drop concentrations today and before the Industrial Revolution.
“We found that using satellite data to try to infer how much radiation is reflected today compared to the amount reflected in the pollution-free pre-industrial atmosphere is very inaccurate,” Penner said. “If one uses the relationship between aerosol optical depth—essentially a measure of the thickness of the aerosols—and droplet number from satellites, then one can get the wrong answer by a factor of three to six.”
These findings are a step toward generating better models, and Penner said that will be the next phase of this research.
“If the large uncertainty in this forcing remains, then we will never reduce the range of projected changes in climate below the current range,” she said. “Our findings have shown that we need to be smarter. We simply cannot rely on data from satellites to tell us the effects of aerosols. I think we need to devise a strategy to use the models in conjunction with the satellite data to get the best answers.”
The paper is called “Satellite-methods underestimate indirect climate forcing by aerosols.” The research is funded by NASA.
PNAS Early Edition: http://www.pnas.org/content/early/recent
Joyce Penner: http://aoss.engin.umich.edu/people/penner
The University of Michigan College of Engineering is ranked among the top engineering schools in the country. At $180 million annually, its engineering research budget is one of largest of any public university. Michigan Engineering is home to 11 academic departments, numerous research centers and expansive entrepreneurial programs. The College plays a leading role in the Michigan Memorial Phoenix Energy Institute and hosts the world-class Lurie Nanofabrication Facility. Michigan Engineering’s premier scholarship, international scale and multidisciplinary scope combine to create The Michigan Difference. Find out more at http://www.engin.umich.edu/.
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You can read the full text of the paper here including the SI: http://www.pnas.org/content/early/2011/07/25/1018526108.full.pdf?with-ds=yes
This figure from the SI is quite interesting:
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The models will be the downfall – because they’ll either fall over completely or they’ll be continually adjusted until they actually do become useful but by then we’ll have realised (well THEY will) that the models were all too alarmist to start with and should never have been the basis for any type of policy or action
Worse than we thought, robust, unprecedented, yatta-yatta.
I think the satellites do a better job than the models. Kaufmann, Kauppi, M.L. Mann and Stock PNAS July 2011 estimated sulfur dioxide emissions in the range 55-75 million tonnes p.a. over the period 1970-2000. and argue this sort of level has been enough since 1998 to explain the “hiatus” in global mean temperature since 1998, despite continuously increasing emissions of carbon dioxide at 3% p.a. since then, to the current level of over 30 Billion tCO2 gross, of which around 14 GtCO2 remain aloft. There seems to be an order of magnitude difference, can it really be that 70 Million tonnes of SO2 are enough to offset whatever warming potential there is in 14 Billion tonnes of CO2?
I suspect the satellites have difficulty tracking the SO2 because there is so little of it being emitted outside the USA and China.
“based on the true modeled preindustrial values” Is that an oxymoron? Can a “true” value of something historical be obtained from a computer model? How are these values verified as “true” if there were no measurements of these in pre-industrial times? I am not implying the results are right or wrong, just curious about the “true”ness.
As I read this, some of the English is obscure. The opening paragraph fails to make clear whether it is the aerosoles or the greenhouse gases whose effects are underestimated The argument advanced seems to be that as the satellite data disagrees with the computer models, the data must be wrong. Does the old English phrase, “ass about face”, summarise the situation, or have I missed something?
At what point precisely, do academia modelists stop & look hard at the real world data, then back at their modelled output, & say, “Now, just hold on one cotton-pickin’ minute!” ? At which point do they put their hands up & admit they could be wrong. I suspect never whilst the financial tap is left well & truly open filling their trough!
So will they be going back and recalculating the amount/effect of aerosols in historical temperatures? Will they be trying to count how many small volcanoes there were a 100+ years ago? Or will they estimate them by using the climate models to tell them how many there should have been? Will they rethink the effect of desulphurisation in the 70s and 80s on the rapidly rising temperatures? If their assessment of how the climate worked in the noughties is wrong then their assessment of how the climate worked on the past is wrong.
Those models that so ‘accurately’ matched the past are just sophisticated computer games where the ending is the only fixed point. It’s always worse than we thought.
Aerosols, the epicycles of the climate world.
Special pleading to provide a case for further special pleading! Is this how science advances?
“Comment from: ianl8888 July 30th, 2011 at 9:42 am
@sean2829
“now its being cited as a source of light reflective aerosols that can explain cooling over the last 10 years.”
The base paper for this assertion is “Anthropogenic sulfur dioxide emissions:1850-2005″, Smith,S.J. et al, Atmos. Chem. Phys., 11, 1101-1116, 2011, wherein Smith et al promote a measurement of the sulphur content of coal burnt in Chinese power stations
Unhappily for this notion of SOx aerosols helping “cool” the planet, the guesstimate of sulphur content in raw/washed coals used in the paper is > 50% higher than laboratory-measured content. Since sulphur content in raw/washed coal is a make-or-break parameter for supply contracts, the widespread lab measurements are accurate and very carefully monitored
Yet another wishful Polyanna notion promoted to a gullible media (which are infested by scientific illiterates and mathematical innumerates)
And, as cementafriend’s post notes:
CSG (coal seam gas) = very, very BAD
LNG (liquified natural gas) = better, mo’ greenie friendly
yet both are methane CH4”
From http://jennifermarohasy.com/blog/2011/07/natural-gas-more-polluting-than-coal-only-according-to-the-ipcc-a-note-from-cementafriend/#comments
“The satellite estimates are way too small,” said Joyce Penner, the Ralph J. Cicerone Distinguished University Professor of Atmospheric Science. “There are things about the global model that should fit the satellite data but don’t, so I won’t argue that the models necessarily are correct. But we’ve explained why satellite estimates and the models are so different.”
Penner and her colleagues found faults in the techniques that satellite estimates use to find the difference between cloud drop concentrations today and before the Industrial Revolution.
“We found that using satellite data to try to infer how much radiation is reflected today compared to the amount reflected in the pollution-free pre-industrial atmosphere is very inaccurate,” Penner said.
So the models are correct and there has to be something wrong with how the satellites estimate the impact? Did I get that right? And they’re saying that the atmosphere was pollution-free before the Industrial Revolution? Well, I suppose aerosols from volcanic eruptions, oceanic spray, continental dust, wildfires, and natural coal fires don’t count as pollution, per se.
“Our findings have shown that we need to be smarter. We simply cannot rely on data from satellites to tell us the effects of aerosols. I think we need to devise a strategy to use the models in conjunction with the satellite data to get the best answers.”
They don’t like what the satellites say, therefore they must be wrong. She says, “I won’t argue that the models necessarily are correct,” then proceeds to do just that. It is to laugh.
Svensmark’s GCR theory keeps advancing to full confirmation, Dr. Spencer has shown how a mere 1 to 2% decrease in global cloud cover can account for the “global warming signal.”
And now Climate Science™ will say: “No no no, we are still right, even though we were wrong! Our CO2->(C)AGW theory dependent on positive feedbacks is still sound! We merely figured in the aerosols, and how they alone affect clouds, wrong! The aerosols have merely masked the CO2 warming effect, it’s really still there! Send us more grant money so we can reprogram the models, and you’ll see our climate models match the observations with peer-reviewed unprecedented accuracy! Don’t believe those climate deniers, only we Climate Scientists™ have always known the only real truth!”
Does that sound like a fair summary?
The faith in models being superior to actual data is … nothing other than a religious faith.
‘Observations don’t match projections’ has becoming a much repeated phrase of late.
The models don’t work.
So, on the one hand soot, because it is dark, absorbs heat and when it lands on glaciers obviously helps melt them, which seems to the case in the Himalayas, as opposed to ‘global warming’. How do you model the impact of burning cow dung and sticks as fuel for cooking in India?
On the other hand, sulphur dioxide helps in cloud formation, which reflects heat back out of the atmosphere.
So burning coal is both good and bad for our planet’s climate. I fail to see how this can possibly be modeled in the context of our planet’s climate, when you also have to deal with El Nino and La Nina cycles, UHI, long term climate cycles, volcanoes, plus general weather and climate ‘chaos’.
Perhaps in the aftermath of the ridiculous budget posturings on Capitol Hill over the past few days, someone will have the sense to say that pouring millions into this type of research is a complete waste of money.
Even if you can model it accurately, which I doubt, will that stop the Chinese, Indians etc. burning coal? The answer is No – perhaps in the countries with goofball energy policies like Britain, Denmark and Germany it might have an effect.
“That may not sound like a broad range, but it straddles the 2-degree tipping point beyond which scientists say the planet can expect more catastrophic climate change effects” – what “2-degree tipping point”, and which scientists claim that? The 2 degrees was simply an arbitrary target for policy makers suggested in 2009.
This paper sounds rather like another brick in the wall of “explain the decline” which is being built now that “ignore the decline” failed to work. Expect more of the same “big on words” but “thin on content” new wallpaper for the crumbling edifice.
First rule of climate science if the values of the models and reality differ, its reality which is in error .
“We found that using satellite data to try to infer how much radiation is reflected today compared to the amount reflected in the pollution-free pre-industrial atmosphere is very inaccurate,” Penner said.
A pollution-free pre-industrial atmosphere? Never heard of natural forest fires? Never heard of natural emissions of volatile organics (like terpenes) from trees, leading to secondary organic aerosols (SOA), causing the haze of the “blue” mountains? These are measured in the free troposphere in a ratio of 2:1 to larger than 10:1 compared to SOx, between 0.5 and 5.5 km altitude. See Heald e.a.:
http://acmg.seas.harvard.edu/publications/heald_2005.pdf
kadaka (KD Knoebel) says:
August 2, 2011 at 2:05 am
Exactly!!!
Just last year, nonagerian James Lovelock, green guru and father of the Gaia hypothesis, cheerfully admitted that climate scientists might all be wrong. That clouds and aerosols might be driving the climate. That the physics aren’t settled yet. And that the best thing to do was to enjoy life. I especially enjoyed his summation of the Stern Review: “If you mix up some science that’s incomplete with some economics which is almost as bad, you’re going to get an absolutely dreadful progeny.” Priceless. Now why does Australian economist Ross Garnaut spring to mind?
Peter Miller says: (August 2, 2011 at 2:35 am)
Even if you can model it accurately, which I doubt, will that stop the Chinese, Indians etc. burning coal? The answer is No – perhaps in the countries with goofball energy policies like Britain, Denmark and Germany it might have an effect.
With regret, Peter, may I ask you to add Australia to the goofball list?
Apparently, overestimating the effects of CO2 leads to overestimating the amount of aerosols to counteract the first fantasy.
The problem with this sort of ‘aerosol’ paper is that it considers only the negative feedback effect which aerosols have on lower troposphere temperature, not both the positive and negative feedback effects.
Please, officer, don’t arrest me! I’m not really speeding. I know you clocked me at 90, but my REAL speed is 45. I know this because I’ve calculated it from digital simulations. My REAL speed of 45 was masked by the rally stripes on my car’s hood, which fooled you into thinking I was going fast.
Wouldn’t work with a cop, shouldn’t work with scientists. Unfortunately scientists and Experts are much dumber than cops.
If the satellite estimates are way too small, then this does not bode well for those who insist that the models hindcasted rather well. — John M Reynolds