University of Helsinki via Eurekalert
Unaccounted feedbacks from climate-induced ecosystem changes may increase future climate warming
The terrestrial biosphere regulates atmospheric composition, and hence climate. Projections of future climate changes already account for “carbon-climate feedbacks”, which means that more CO2 is released from soils in a warming climate than is taken up by plants due to photosynthesis. Climate changes will also lead to increases in the emission of CO2 and methane from wetlands, nitrous oxides from soils, volatile organic compounds from forests, and trace gases and soot from fires. All these emissions affect atmospheric chemistry, including the amount of ozone in the lower atmosphere, where it acts as a powerful greenhouse gas as well as a pollutant toxic to people and plants.
Although our understanding of other feedbacks associated with climate-induced ecosystem changes is improving, the impact of these changes is not yet accounted for in climate-change modelling. An international consortium of scientists, led by Almut Arneth from Lund University, has estimated the importance of these unaccounted “biogeochemical feedbacks” in an article that appears as Advance Online Publication on Nature Geoscience‘s website on 25 July at 1800 London time. They estimate a total additional radiative forcing by the end of the 21st century that is large enough to offset a significant proportion of the cooling due to carbon uptake by the biosphere as a result of fertilization of plant growth.
There are large uncertainties associated in these feedbacks, especially in how changes in one biogeochemical cycle will affect the other cycles, for example how changes in nitrogen cycling will affect carbon uptake. Nevertheless, as the authors point out, palaeo-environmental records show that ecosystems and trace gas emissions have responded to past climate change within decades. Contemporary observations also show that ecosystem processes respond rapidly to changes in climate and the atmospheric environment.
Thus, in addition to the carbon cycle-climate interactions that have been a major focus of modelling work in recent years, other biogeochemistry feedbacks could be at least equally important for future climate change. The authors of the Nature Geoscience article argue that it is important to include these feedbacks in the next generation of Earth system models.
This work was promoted by iLEAPS (Integrated Land Ecosystem and Atmospheric Processes), a core project of the International Geosphere-Biosphere Programme, and developed through workshops supported by the Finnish Cultural Programme.
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Journal Reference: (note the actual paper was not provided with this press release)
A. Arneth, S. P. Harrison, S. Zaehle, K. Tsigaridis, S. Menon, P. J. Bartlein, J. Feichter, A. Korhola, M. Kulmala, D. O’Donnell, G. Schurgers, S. Sorvari & T. Vesala. Terrestrial biogeochemical feedbacks in the climate system. Nature Geoscience, July 25, 2010 DOI: 10.1038/ngeo905
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So Dyson suggests that there are many unaccounted for feedbacks and suddenly they are found to be positive. The model is correct again. On further reading Dyson suggests get out of the air conditioned computer lab and do some measurements. Did that happen? How about the proof that the measurements indicated the cause?
“There are large uncertainties associated in these feedbacks”
Huh. Imagine that.
Crap! It’s worst than we thought!!! Although we admittingly don’t know very much about many of the feedbacks, we’re pretty sure its gonna be real bad once it reaches a tipping point. sigh.
“There are large uncertainties associated in these feedbacks….”
My Grandma once thought me to keep my big mouth shut until I know exactly what I’m talking about.
These warmists need a lesson or two from my grandma.
Good to see A. Arneth, S. P. Harrison, S. Zaehle, K. Tsigaridis, S. Menon, P. J. Bartlein, J. Feichter, A. Korhola, M. Kulmala, D. O’Donnell, G. Schurgers, S. Sorvari & T. Vesala pondering this important question, and after serious pondering, coming to the conclusion that it “may increase future climate warming” and that “There are large uncertainties associated in these feedbacks”. What would we do without A. Arneth, S. P. Harrison, S. Zaehle, K. Tsigaridis, S. Menon, P. J. Bartlein, J. Feichter, A. Korhola, M. Kulmala, D. O’Donnell, G. Schurgers, S. Sorvari & T. Vesala.
“There are large uncertainties associated in these feedbacks”
“The authors of the Nature Geoscience article argue that it is important to include these feedbacks in the next generation of Earth system models.”
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Has not stopped them in the past, so why not?
Let’s put something in the computer games that we have absolutely no understanding of, and then make outrageous claims about the future.
A “what if” document.
I completely ignore.
We have a local consulting psychologist, Lucinda Basset. She works with chronic worriers, people FROZEN by “what if” thinking.
It’s a serious mental malady. Nothing to joke about.
Max
It would be interesting if the authors were to give, in the abstract of their article, some indication of the degree of uncertainty associated with their suppositions. In addition, they might indicate (also in the paper’s abstract) whether their work shows causation or only correlation.
Today’s entry in the ‘it’s worse than we thought’ literature
Have you tried to simulate a simple model using Simulink/Matlab?
Models are not fact or observational data.
When is this virtual reality crap going to stop?
“(…)it acts as a powerful greenhouse gas as well as a pollutant toxic to people and plants.”
— as a what?!!!
Why is it so in climate science that all uncertainties are of the same sign, the publishable sign, so to speak?
Just forget it: The system in the picture above is an ELECTRIC CIRCUIT!
OT: We need a post on the STORM on Washington. A COLD front is Summertime….Run!, Climate Change is here!
[sings] “The only way is up!” [/sings]
Given the content of the article, couldn’t the headline have read this instead?
Another espisode in the Lara Croft XBox360 fantasy world! Call me Mr Cynical, sounds like someone is doing some goal-post shifting to me! Classic advocate behaviour, move on to something else before what’a already been said can be analysed for certain! Eg Global Warming, to Climate Change, to Ocean Acidification, etc. Always handy to have the other what ifs in the bank for later use.
1. It is the “+” sign in the diagram that indicates these are not scientists, in the best understanding of the term. The sign should either be a “?” or “+/-“, but that would probably interfere with future funding of their research.
Historical facts in the Earth’s Geo/Bio/whatever record indicate that the net feedback must be negative for the whole system. Despite a large range of conditions, the global mean temperature has only varied by a few percent (using a Kelvin scale) in the last billion or so years. This would seem to indicate a central equilibrium around which the temp deviates due to various proddings (eg., orbital anomalies, solar change, maybe variance in the interstellar dust density as the solar system revolves one its orbirt in the Milky Way.)
There exists a weasel word in the title and in the first sentence, second paragraph, a declaration they don’t know what they’re doing. Perhaps they should go to Hogwarts – er, UEA, and consult the sorting hat.
They should eat this up at RC.
“Nevertheless, as the authors point out, palaeo-environmental records show that ecosystems and trace gas emissions have responded to past climate change within decades. ”
CO2 levels have been increasing since the industrial revolution. Their levels have skyrocketed since the 1940s. It has been at least 6 decades already. Is that not enough to see how the ecosystem responds to trace gas emissions?
John M Reynolds
Dave L says:
July 26, 2010 at 7:47 am
Models are not fact or observational data.
When is this virtual reality crap going to stop?
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Dave, ask any person if they think our climate is static, and they will say no.
Then ask them, since it’s not static, which is better warmer or colder.
They will all say warmer, and colder would be a catastrophe.
Ask any person if they think we know enough to design computer models to predict the future.
They will tell you no.
There’s only one reason for anyone to believe any of this.
They are hearing what they want to hear.
The crap will never stop, as long as there are people that are hearing what they want to hear.
Nature and Nature Geoscience must front for the JournoList of leftist pseudo-scientists who continually spout a party line without one shred of hard evidence. Uncertainties? Massive Uncertainties? Who — what climate “scientist” — must account for these? Not us!
“There are large uncertainties associated in these feedbacks….”
Yeah, but the media will ignore that bit and focus on the headline… “It’s worse than we thought”
From what I read I heard…
The models are incomplete and wrong, SO we must add more stuff that ONLY forces the models to show even more warming.
Forget the negative feedbacks. Ignore the ACTUAL climate sensitivity to CO2, just make the models show new and more scary ways that ONLY show warming.
I am not convinced. Can ya tell?
We’ve seen approximately 0.5 of a doubling of CO2 concentration, which would be an increase of 41.4%. [In logarithmic terms, half of a doubling means an increase to the square root of 2 times the original level.] The increase has been going on for about a century, so any feedbacks which operate on a scale of a few years to decades will have been largely or fully realized.
We’ve seen approximately 0.5 K increase in mean surface temperature. [Per IPCC AR4 WG1 FAQ9 figure 2, temperature increases up to ~1950 can be accounted for with natural (non-anthropogenic) causes.]
So whatever feedback paths exist with short-to-medium time scales, they’re not scary.