Amplification of Global Warming by Carbon-Cycle Feedback Significantly Less Than Thought, Study Suggests
from ScienceDaily (Jan. 28, 2010) — A new estimate of the feedback between temperature and atmospheric carbon dioxide (CO2) concentration has been derived from a comprehensive comparison of temperature and CO2 records spanning the past millennium.
The result, which is based on more than 200,000 individual comparisons, implies that the amplification of current global warming by carbon-cycle feedback will be significantly less than recent work has suggested.
Climate warming causes many changes in the global carbon cycle, with the net effect generally considered to be an increase in atmospheric CO2 with increasing temperature — in other words, a positive feedback between temperature and CO2. Uncertainty in the magnitude of this feedback has led to a wide range in projections of current global warming: about 40% of the uncertainty in these projections comes from this source.
Recent attempts to quantify the feedback by examining the co-variation of pre-industrial climate and CO2 records yielded estimates of about 40 parts per million by volume (p.p.m.v.) CO2 per degree Celsius, which would imply significant amplification of current warming trends.
In this week’s Nature, David Frank and colleagues extend this empirical approach by comparing nine global-scale temperature reconstructions with CO2 data from three Antarctic ice cores over the period ad 1050-1800. The authors derive a likely range for the feedback strength of 1.7-21.4 p.p.m.v. CO2 per degree Celsius, with a median value of 7.7.
The researchers conclude that the recent estimates of 40 p.p.m.v. CO2 per degree Celsius can be excluded with 95% confidence, suggesting significantly less amplification of current warming.
Journal Reference:
- David C. Frank, Jan Esper, Christoph C. Raible, Ulf Büntgen, Valerie Trouet, Benjamin Stocker, & Fortunat Joos. Ensemble reconstruction constraints on the global carbon cycle sensitivity to climate. Nature, 2010; 463 (7280): 527 DOI: 10.1038/nature08769
Full story here at Science Daily
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an LWIR ray is absorbed after 10m or so if it is in the absorption band of CO2.>
sorry Dirk, misunderstood your point. I may be getting in over my head here, but… if an LWIR hits a CO2 molecule, the temperature of the CO2 molecule goes up. Now the CO2 molecule starts radiating energy because it is hotter than was before. The energy it radiates has two options. It can go downward, in which case it hits either another molecule in the atmosphere or else earth’s surface. The second option is that it goes sideways or up, in which case it will either hit another molecule or escape into space. If it hits another molecule…
In brief, no matter how close to earth’s surface it is 100% absorbed, the retained energy must be propogated through the system with some energy heating up the atmosphere, some heating up the earth, and some escaping into space. It may have to be radiated and re-radiated a hundred times to escape into space, but some does. More CO2…. less does.
Of course some gets transfered by conductance instead of radiance OH FOR GOSH SAKES MY HEAD HURTS I’M FINISHING MY WINE AND GOING TO BED.
Oops – forgot to ask. any confectionists hanging around? My recollection is that Pamela’s chocolate mousse is whipped with CO2 to make it fluffy? So she’s eating the global warming?
Pamela Gray (19:04:40) :
If I wasn’t already spoken for…….
8)
Gobsmacked? Gob is UK slang for mouth, hence Gobby and other far less flattering concoctions. The image that the usage of gobsmacked is meant to produce is mouth slightly open as head is twisted sideways by A.N. Other’s fist meeting jaw. Eyes crossed, half closed, glassy. With a little dribble flying from the lip opposite the impact point. Possibly unflattering.
Wait wait… so like increasing CO2 concentration makes plants grow? So like a planet that has survived millions of years might not have crazy positive feedback loops but in fact negative ones? 🙂
Deech, are you saying that if we started at 1 ppm, doubling that would add approx. 1C warmth to the globe?
So by the time we got to 356 ppm about 9C of our average temp of 15C would be solely from CO2?
This doesn’t seem right to me.
Or is that added to the 15C? then we should be on average about 24C.
Arrgghh, this is why I refuse to get off the fence! I don’t understand this logic!
there has to be a starting point. Gavin suggested maybe the first 50 ppm raised the temp 1C, then the doubling starts, but again, where is the research on this? How can we say how much effect a doubling of CO2 will have on this planet if we don’t know where the starting point is???
Henry Galt
When did the very first, mythical if you will, doubling occur?>
funny thing that. Everyone assumes it already did. Skim the IPCC report and you get that impression. Read the detail…. and its up (their number, not mine) 38% over pre-industrial (last 90 years). Then they show a bunch of math to suggest that the rate of increase has accelerated, and then make the assumption that it will CONTINUE to accelerate. The supply of fossil fuels being infinite you see, and the number of oil wells we can drill going up by a factor of 10 every year, I can see how that might happen and get us to double in less than another 180 years or so. NOT!
@ur momisugly Jeff L (13:58:40)
Thanks for taking the time to go through that exercise. What you did suggest is that Dr. Spenser, Sr. may be incorrect too as I am reading it. To fit using your exercise, it has to assume that CO2 is solely the cause for warming. It would also then have to assume that CO2 fell until the end of LIA.
So, the real model refutation would be that if there was no corresponding drop in CO2 leading into the LIA, CO2 cannot be causal. I don’t remember seeing that graph of CO2 concentrations being higher before the LIA. Or is that too obvious?
And why is 280 the right answer? I always thought that the ultimate answer was 42!
Henry! You devil! That isn’t unflattering! It kinda reminds me of…er…um…never mind (as she sips her red wine with just a touch of a faraway glimmer in er’ eyes).
Mods, snip at will.
>>
Leif Svalgaard (19:22:32) :
estimates of 40 p.p.m.v. CO2 per degree Celsius
I don’t want to pay $30+ to read the paper [or do it on Stanford time], but isn’t this backwards? I would have thought the estimate should have been of degrees Celsius per ppmv of CO2. Is this just me getting it backwards?
<<
I see DirkH already answered. There are two black boxes in this feedback loop. One takes CO2 as input and outputs a temperature. This is the basic non-feedback response of the planet to CO2. The units are what you would think: degrees Celsius per p.p.m.v. of CO2. The feedback box takes temperature as input (the output of the first box) and outputs CO2 (adds to the input of the first box). It’s called gamma in the paper and the units are p.p.m.v. of CO2 per degree Celsius. They really don’t explain it well in the paper, so save your money.
Jim
davidmhoffer (19:37:13) :
To be honest, i don’t know which part of the radiation goes where and whether the multiple-blankets-analogy of the warmist crowd has any merit. I stopped pondering the possibilities when i understood what Miskolczi says. Not that i understand his theory, i understand the consequences i think.
What bolstered my confidence was the blunt assertion of Prof. Gerlich that “the greenhouse effect has no basis in thermodynamics.” If physicists talk like that, they’re usually on to something. Gerlich might be overly simplistic here, though. What matters is the distribution of the available energy, and he doesn’t really explain that.
To repeat: Hypothesized anthropogenic global warming (AGW) due to “greenhouse gas” accumulations of atmospheric CO2 is mathematically and physically impossible.
First, Edward Lorenz in 1964 postulated that due to “sensitive dependence on initial conditions” aka the Butterfly Effect, complex dynamic systems –those with three or more interacting variables– are non-random but indeterminate, that is, configuring “strange attractors” (qv) that render linear extrapolation an impossibility. Combined with Benoit Mandelbrot’s seminal “fractal geometry” (1974), Lorenz’s Chaos Theory guarantees that regardless of computing power or programming sophistication there can be no, repeat NO, valid model of planetary atmospheric processes, any more than Newton’s “three-body problem” is solvable regardless of spurious numerical precision.
Second, physics’ fundamental thermodynamic Conservation Laws require that heat must dissipate from “open systems” while “closed systems” entail entropy, tending to thermal equilibrium by cooling rather than by warming processes. This is because heat is a form of energy, generated only by inherently inefficient “work” which itself requires energy input. Thus Climate Cultists, Warmists who posit escalating concentrations of atmospheric CO2, are classic Perpetual Motion charlatans. Though geophysical effects may alter climate conditions for extended periods, as a planetary “open system” Earth’s atmospheric heat-engine never can induce sustained “global warming”, anthropogenic or otherwise.
What “Glaciergate” (sic) teaches is that Ban Ki-moon’s dysfunctional UN, with the peculating Pachauri as its IPCC climate guru, never so much as proofreads figures (2350 becomes 2035 without demur) while publishing prima-facie idiotic theses: Even if a 1,000-foot Himalayan glacier shrinks to nothing over twenty-five years at a rate of forty feet per year (completely implausible over an annual three-month summer season), where are the raging meltwaters flooding tens of thousands of square miles downstream? Twelve-year old Sixth Graders giggle uncontrollably– but not IPCC panjandrums promoting Statist agendas under cover of “settled science” propaganda-drives .
Fire Pachauri. Abolish the IPCC and with it nihilistic Luddite sociopaths’ scarifying stab at global tyranny, Ban ki-moon’s Green Gang aka the utterly discredited UN. Prosecute Briffa, Hansen, Jones, Mann, Trenberth et al., beginning with their chief cap-and-trader in Thieves’ Markets, Big Al Gore. Maybe he could share a cell with Gordon Brown, Kevin Rudd, withal the U.S.’s reptilian Barak Hussein Obama/Soetoro with his Farrakhanist Black Muslin confreres. Can’t happen soon enough.
Isn’t Hawaii under that yellow band in the Pacific Ocean? Doesn’t that mean that the Hawaii record is NOT representative of the planet (since there is all that blue…)? Doesn’t the picture state clearly that CO2 is “not well mixed” in the air? Isn’t that a fundamental assumption in a lot of the modeling being done?…
http://news.xinhuanet.com/english2010/sci/2010-01/29/c_13155132.htm
anyone familiar with this paper?? looks like a an opening to more funding does it not?? waht is scary is SS’s name being attached.
regards
davidmhoffer (19:52:17) :
Yep. I got that impression also.
I like 22ppmv as first doubling – I read a CO2 laser specialist’s paper on the subject when first I had the scales lifted from mine eyes.
Pamela Gray (19:58:46) : Not once have you failed to bring a smile to my face whenever I’ve read your comments.
It is 4AM and I must fly away home….
sorry. after a longer read I found a previous mention.
these posts are getting too long.
regards
Jim Masterson (20:03:55) :
The feedback box takes temperature as input (the output of the first box) and outputs CO2
So, when that is less than what was thought, then it really says that the warming observed is more due to the first box than to the feedback, thus in support of AGW, no?
My own theory on that is the first mythical doubling occurred after skeptics started throwing around “Popper” and “falsifiability”.
Since somewhere between 90 and 100% of AGW experiments and conclusions are conducted in the future, it didn’t take a genius to marginalize Popper that way too. Let’s face it, it worked to some extent, as even Lindzen, Spencer and others have fallen into the “data from the future” trap by talking in terms of CO2 doubling.
In other words – we follow all of Popper’s principles, but you will need to come back when CO2’s at 560 ppm, or 780 ppm, or …. ad infinitum to discuss falsifiability.
Free beer tomorrow.
http://en.wikipedia.org/wiki/Falsifiability
John Blake (20:10:06) :
there can be no, repeat NO, valid model of planetary atmospheric processes, any more than Newton’s “three-body problem” is solvable regardless of spurious numerical precision.
And yet, we solve easily Newton’s N-body problem [N much larger than three] to any desired high precision in our calculations of an Astronomical Ephemeris or of the orbit of a spacecraft. Be careful about drawing analogies like that [they better be correct…].
>>
Leif Svalgaard (20:21:57) :
So, when that is less than what was thought, then it really says that the warming observed is more due to the first box than to the feedback, thus in support of AGW, no?
<<
They do mention the LIA and MWP, but the temperature reconstructions look like hockey sticks, I believe Mann’s reconstruction is present, lots of comments from the IPCC, and the usual references to anthropogenic carbon emissions. I would say the paper is in full support of AGW.
Jim
The science is settling down.
John, can you please elaborate on this point? How does this study show this?
DirkH (16:51:17) :
“The more confused the reasoning becomes, the faster people will just refuse to believe it anymore!”
I’m just waiting for the climate modelers to introduce epicycles.
Henry Galt (19:05:28) :
“Every day (every shift lol) I check out WUWT and thank my lucky stars I am surrounded by people such as Ed, George, Tilo, Jeff L, Steven, Leif, Lucy, Roger, davidmhoffer et al. Of course our host and the mods. The gloriously funny commentary. The wit and wisdom. The side issues, OTs and diversions.”
Agreed in spades, Mr. Galt. I became skeptical within 48 hours of first hearing the AGW scare, but not through science. History was my path, and I knew full well that earth was warmer 1,000 and 2,000 years ago, and furthermore that life was much, much better then than in the cold times which followed those warm periods.
It was a lonely position to hold. I was considered a miserable nut-bar. But over the last couple of months I have become a far happier nut-bar. I smile, I even laugh, and I do not kick small children nearly as hard as before.
This story with its very interesting comments has pleased me greatly. Except for one comment. Pamela Gray:
“By the way, that new jello mousse, the decadent chocolate kind with only 60 calories? I know it’s just whipped filled-with-air pudding and I’m paying more for less, but gawdamighty it is good with red wine.”
Ms. Gray, unaccountably you have omitted some all-important information. How is it with hair? Do finish that bottle of wine, dear, and run the experiment. Fine, eager minds here await your report.
But only, of course, if it is peer-reviewed.
Just for reference, in my comments up above, the only feedback effect I was considering was that referenced in the main article — the 7.7 ppm linear release of CO2 per degree Celsius, presumably from oceanic out-gassing. This is a positive feedback effect and as stated, it is a closed loop effective value rather than the open loop effect I assumed — same value, almost.
I believe the nominal thermal gain is more precisely (1/Ln(2))*(1/380) at 380 ppm CO2 concentration assuming a 1 degree Celsius temperature increase per CO2 concentration doubling. The units are degrees Celsius global temperature increase per one ppm CO2 concentration increase.
It took me a while to figure out what hair had to do with chocolate mousse! You must mean the kind of stuff one puts in ones hair to keep it in place! Something about Mary I suppose.
[REPLY – Wooing the mousse? ~ Evan]