From NASA Earth Science news: A new NASA computer modeling effort has found that additional growth of plants and trees in a world with doubled atmospheric carbon dioxide levels would create a new negative feedback – a cooling effect – in the Earth’s climate system that could work to reduce future global warming.
The cooling effect would be -0.3 degrees Celsius (C) (-0.5 Fahrenheit (F)) globally and -0.6 degrees C (-1.1 F) over land, compared to simulations where the feedback was not included, said Lahouari Bounoua, of Goddard Space Flight Center, Greenbelt, Md. Bounoua is lead author on a paper detailing the results that will be published Dec. 7 in the journal Geophysical Research Letters.
Without the negative feedback included, the model found a warming of 1.94 degrees C globally when carbon dioxide was doubled.
Bounoua stressed that while the model’s results showed a negative feedback, it is not a strong enough response to alter the global warming trend that is expected. In fact, the present work is an example of how, over time, scientists will create more sophisticated models that will chip away at the uncertainty range of climate change and allow more accurate projections of future climate.
“This feedback slows but does not alleviate the projected warming,” Bounoua said.
To date, only some models that predict how the planet would respond to a doubling of carbon dioxide have allowed for vegetation to grow as a response to higher carbon dioxide levels and associated increases in temperatures and precipitation.
Of those that have attempted to model this feedback, this new effort differs in that it incorporates a specific response in plants to higher atmospheric carbon dioxide levels. When there is more carbon dioxide available, plants are able to use less water yet maintain previous levels of photosynthesis. The process is called “down-regulation.” This more efficient use of water and nutrients has been observed in experimental studies and can ultimately lead to increased leaf growth. The ability to increase leaf growth due to changes in photosynthetic activity was also included in the model. The authors postulate that the greater leaf growth would increase evapotranspiration on a global scale and create an additional cooling effect.
“This is what is completely new,” said Bounoua, referring to the incorporation of down-regulation and changed leaf growth into the model. “What we did is improve plants’ physiological response in the model by including down-regulation. The end result is a stronger feedback than previously thought.”
The modeling approach also investigated how stimulation of plant growth in a world with doubled carbon dioxide levels would be fueled by warmer temperatures, increased precipitation in some regions and plants’ more efficient use of water due to carbon dioxide being more readily available in the atmosphere. Previous climate models have included these aspects but not down-regulation. The models without down-regulation projected little to no cooling from vegetative growth.
Scientists agree that in a world where carbon dioxide has doubled – a standard basis for many global warming modeling simulations – temperature would increase from 2 to 4.5 degrees C (3.5 to 8.0 F). (The model used in this study found warming – without incorporating the plant feedback – on the low end of this range.) The uncertainty in that range is mostly due to uncertainty about “feedbacks” – how different aspects of the Earth system will react to a warming world, and then how those changes will either amplify (positive feedback) or dampen (negative feedback) the overall warming.
An example of a positive feedback would be if warming temperatures caused forests to grow in the place of Arctic tundra. The darker surface of a forest canopy would absorb more solar radiation than the snowy tundra, which reflects more solar radiation. The greater absorption would amplify warming. The vegetative feedback modeled in this research, in which increased plant growth would exert a cooling effect, is an example of a negative feedback. The feedback quantified in this study is a result of an interaction between all these aspects: carbon dioxide enrichment, a warming and moistening climate, plants’ more efficient use of water, down-regulation and the ability for leaf growth.
This new paper is one of many steps toward gradually improving overall future climate projections, a process that involves better modeling of both warming and cooling feedbacks.
“As we learn more about how these systems react, we can learn more about how the climate will change,” said co-author Forrest Hall, of the University of Maryland-Baltimore County and Goddard Space Flight Center. “Each year we get better and better. It’s important to get these things right just as it’s important to get the track of a hurricane right. We’ve got to get these models right, and improve our projections, so we’ll know where to most effectively concentrate mitigation efforts.”
The results presented here indicate that changes in the state of vegetation may already be playing a role in the continental water, energy and carbon budgets as atmospheric carbon dioxide increases, said Piers Sellers, a co-author from NASA’s Johnson Space Center, Houston, Texas.
“We’re learning more and more about how our planet really works,” Sellers said. “We have suspected for some time that the connection between vegetation photosynthesis and the surface energy balance could be a significant player in future climate. This study gives us an indication of the strength and sign of one of these biosphere-atmosphere feedbacks.”
Patrick Lynch
NASA’s Earth Science News Team
Piers Corbyn has been talking about cooling from plants for years, though not the same as the “new” finding from NASA. He’s ahead of NASA too.
Wait, what?!?! You mean it’s NOT worse than we thought???
Well that’s a first!
WillR & Mike Davis. I would be more than willing to join in your research. My tree however has brick-built walls with an internal heat source which may invalidate it. On the other hand; the level at which my hands are normally poised, desk top, is about 5°C warmer than the floor, (best case), and the internal heat source cannot maintain greater than 18°C in daytime & less at night.
DaveE.
“…plants are able to use less water yet…increase evapotranspiration on a global scale.”
Darn clever stuff!
…said co-author Forrest Hall, of the University of Maryland-Baltimore County and Goddard Space Flight Center. “Each year we get better and better….”
There there. Just lie down quietly for a bit and you’ll be fine.
Raw forcing per CO2 doubling is 1C. Assuming the IPCC is right.
Any estimate above that is including positive feedbacks. At this point there is zip evidence for and preliminary evidence against positive feedbacks.
Plus, climate has been on a warming trend for 350 year. Where’s the positive feedback? At 40% increase in CO2, we have an “adjusted” (i.e., probably exaggerated) warming of +0.7C. Over a time span that starts in a PDO/AMO cold phase and ends in a PDO/AMO warm phase. So where is there “room” for any positive feedback? Overall negative feedback fits those numbers better.
D’Oh!!! … Look out, NASA scientists doin’ press release science again….. Handle with care… Could be toxic, explode, fail or just go splat…. LOL.
WILLR; Mike Davis, I have the beer, now do we use hammacks, lounge chairs or standard chairs. We definitly need to get together on this might i suggest taking turns on the napping to monitor sleep patterns.
What I just love is how they seem to manage, with all sincerity, to say “Look! We screwed up and totally missed this major negative feedback that probably accounts for 15% of the postulated temperature at CO2 doubling.”
And then turn around and say, without dying of shame or at least stuttering and turning bright red “This discovery just shows how GREAT we are, and we’re getting BETTER ALL THE TIME!!!”
Sheesh.
If these people had been in charge of the moon mission, we’d STILL not be there, and gawd knows how many astronauts and engineers associated with the project would have died in the meantime. Hoover Dam would be about 2 ft. high and they’d still be modeling it. But we’d be getting regular press releases about their amazing progress and how much they’d miraculously managed to advance the state of knowledge! They’re closing in on something that’ll work, just you wait and see (and send money).
Translation?
Our computer models turned out to be so wrong and inaccurate and flawed we needed to find some kind of mechanism we discarded in the beginning because it contradicted the CAGW dogma while still being able to blame CO2 and still claim rising temperatures despite the reality.
Even though the models that we claimed were perfect and infallible were badly designed and included false assumptions and bad data which did failed to predict the climate, the weather, the global temperatures we cannot do without them because the whole CAGW house of cards would collapse and with it the reputations of NASA and its staff and so we have to search around desperately for any mechanism that we can attach to the models instead of binning the models and admitting failure.
NASA cannot admit the truth and they cannot go back to the beginning and start over, they cannot admit errors and mistakes and incompetence and cover ups and made up trash science and fiddled figures, they have painted themselves into a corner and there really is no way out for them other than to bluster and hope the paint eventually dries.
I suspect that if NASAs books were opened up by auditors and if the house and senate get around to launching a full inquiry and start taking names and kicking some ass the stink emanating from NASA will make ENRON look like a non event. I would like to see Sen Inhofe come before the press and announce a full investigation into NASA.
MAGICC? What an appropriate name for a climate model:
mag·ic (mjk) n. 1. The art that purports to control or forecast natural events, effects, or forces by invoking the supernatural.
If, as Lord Monckton of Brenchley, points out in his second Mexican Missive (http://wattsupwiththat.com/2010/12/07/moncktons-mexico-missive-2/), “the true rate of warming over land in the past half-century had been little more than half of what the official record showed.” then what effect would this negative feedback then have?
Could the “Gaia” concept be working after all?
My guess is that the sowtware in those computers are now so full of bug-fixes and modifications that noone can understand anything of whats going on in there.
Soon they will need billions to re-make the whole thing.
Hmm, all I heard was blah blah Model blah blah .. I couldn’t really get much more than that out of it.
Sorry, I just can’t seem to pay much attention to phrases that contain the word “model” anymore.
“…Scientists agree that in a world where carbon dioxide has doubled – a standard basis for many global warming modeling simulations – temperature would increase from 2 to 4.5 degrees C (3.5 to 8.0 F)….”
The effect on forest growth of a 2.5° to 7.0°C increase in the Arctic temperature (presumably without any increase in CO2) can be seen in tree line studies of northern Russia and Canada.
For instance a study by Glen M. MacDonald et al. (March 1999) concluded that “the mean July temperatures along the northern coastline of Russia may have been 2.5° to 7.0°C warmer than modern” during the Holocene Optimum (9000-7000 yr. B P):
http://4.bp.blogspot.com/_Lxqre8hMG3M/SeaQl9E0ozI/AAAAAAAAALo/V0bPCy44D9s/s400/weatherformerTreeline.jpg (google to find pdf).
A quick google search came up with other more recent studies which put the temperature no greater than + 2°C, but there is ample evidence of the pressure on scientists to conform to IPCC orthodoxy which, like its ‘hockey stick’ counterpart, is incredible:
http://upload.wikimedia.org/wikipedia/commons/c/ca/Holocene_Temperature_Variations.png
You would think that the ‘greening’ of the Earth would please our friends at ‘Fiends of the Earth’, ‘Greenpreach’ etc. but of course you would be wrong.
Me been a iggorunt bugger, I ‘ave ta ask this 2 kwestshuns!
I can’t keep that up LOL
1) If you go out in the Arizona desert, you will find rock-pools which are perpetually frozen, is the GHG effect not strong enough to work even when the air temperature is above 30°C?
2) I have noted in my travels that generally…
a) humid areas are cooler but maintain their temperatures overnight
b) arid areas heat up quickly & also cool quickly.
I know the argument for 2) a) It’s the GHG H2O preventing the cooling!
What about it’s the specific & latent heat of water preventing the cooling?
The more I look, the more I think that surface radiative energy loss is irrelevant
DaveE.
Mike Davis says:
December 7, 2010 at 7:50 pm
I’m with you both. I like to perform this test by the pool under a nice shady palm tree, or even a fern (ferns are trees downunder where it is warmer – warmer being better). The Cold Beer test is also a jolly good idea!
I also have a ‘trained observer’. This is my wife: I have trained her not to throw things at me when I start snoring….
Here’s an idea. Finish learning enough about how our planet really works AND THEN tout your models.
Stop doing it backwards!!!!
Translation:
We still don’t have a clue. $end billions.
NASA to all staff could you all go home tonight and think up anything that will result in a very big grant as we need it . we may have a surprise for anybody that comes up with the biggest untruths
Like I’ve said in several comments on previous threads – CO2’s effect on climate is about biology first, physics second.
I think I finally understand how all these adjustments work. Its cyclical. First they did all the positive adjustments and now they’ve started working on the negative adjustments.
Assistant; Sir, I just finished that computer model you wanted. Its bang on sir. I put the accelerated warming trends in just like you said, and boy, every single run it produces an accelerated warming trend. This is scary stuff. One problem sir…
Professor; No problem, look at these graphs! Excellent! And exactly the same every time no matter what data we use. Proof! Proof!
Assistant; …uhm, but, they ACTUAL temperatures don’t match…
Professor; Nonsense. Impossible. Let me see those….. Hmmmm. These temperatures can’t possibly be right. There’s something wrong with them.
Assistant; But those are the temperature records we’ve been using for decades, perhaps the model….
Professor; Proof! The model is proof! Therefore these temperature records must be wrong. Adjust them.
Assistant; …uhm, adjust them? How will I know how much to adjust them?
Professor; Until they match the proof you idiot.
Assistant; Sir, I’ve adjusted the temperature data until it fits the… uhm, model. But its getting harder and harder to adjust them sir. The divergence problem keeps getting bigger, and frankly sir, I think we may have accidently hidden the decline with our adjustments and its sort of becoming obvious that we’ve tricked the data out like this…
Professor; Nonsense. You’re never going to get a PhD that way. The model is proof. That’s why we had to adjust the temperature data. But you see we didn’t adjust it enough. Take the last 5 years of adjustments, apply them again, but this time with a negative sign but call it a different name. Just make something up. Write a paper. Get published. Then do another five years, make up another name and apply that negative too.
Assistant; Uhm, OK. And I keep doing that until….
Professor; Moron! Until it matches the original data of course! We’ll just keep on adjusting and adjusting until all the adjustments cancel each other.
Assistant; But… wouldn’t it make more sense to just start with the original data and never adjust it at all?
Professor; Dolt. Who’s gonna publish a peer reviewed paper that is just a photocopy of the data? You want a degree, you got to adjust things, justify them, make them increasingly accurate, until you’re right bang on and then its proof.
Assistant; But you said the very first one was proof…
Professor; Sigh. You just don’t understand science boy. Sorry. You’re fired.
Assistant; Fine. I’ll clean out my desk. And I’ve got a bunch of files on the server that are mine, I’ll just download them onto this gigantic usb hard drive over hear. Ooops, they shut off my account already. Look, I’ve done good work for you and those are my files, what did you say the admin password was? Take me an hour and then I’m out of here…
NASA climate model. Big yawn flops down cool shade under tree zzzzz
Piers Corbyn says:
December 7, 2010 at 7:01 pm
Anthony,
And NASA think this is ‘New’! We have been saying it for years – but I would put it more strongly: Plants through photo-transpiration cooling, which is enhanced by more CO2, VETO any CO2 claimed atmospheric warming
———–
Sorry but an argument along the lines of “I want AGW to go away, transpiration cause cooling, therefore transpiration must produce so much cooling that it vetoes CO2” does not fly.
Certainly everyone and his fog knows that transpiration cause cooling and the scientists know it better than you. But there are a zillion confounding factors and no one knows what the sum total result is.
For you to claim that you knew the answer all along because your belly button fluff said so is bogus.
Let’s throw a dice, I bet heads, I win the bet, I boast that I knew all along that it was going to be heads. Am I telling the truth?
Given the criticism of their work on arsenic-based bacteria, I would be quite leery of another climate computer model from NASA. Even though, as Piers Corbyn notes above, that there is nothing new about the idea that more trees and plants should have a negative feedback on warming.
Mike O says:
December 7, 2010 at 6:36 pm
The amazing thing to me is the hubris of people who believe that they can accurately model something as complex as the climate of the Earth.
As a scientist myself
————
Well it looks to me like you are not keeping up to date.
The trend in science is to try and solve more and more difficult problems. Many of those problems involve complex systems with lots of moving parts. Typically they are becoming too complex for an individual person to describe or reason about. That’s why computer models are the only way forward.
The obverse of what you describe inaccurately as hubris is defeatism, stagnation and lack of imagination.