One has to wonder though, since CO2 residence time has been said to be anywhere from five year to hundreds, or even thousands of years, with no solid agreement yet, how they can be so sure of themselves?
From the University of Cambridge
4 degree rise will end vegetation ‘carbon sink’
Latest climate and biosphere modelling suggests that the length of time carbon remains in vegetation during the global carbon cycle – known as ‘residence time’ – is the key “uncertainty” in predicting how Earth’s terrestrial plant life – and consequently almost all life – will respond to higher CO2 levels and global warming, say researchers.
Carbon will spend increasingly less time in vegetation as the negative impacts of climate change take their toll through factors such as increased drought levels – with carbon rapidly released back into the atmosphere where it will continue to add to global warming.
Researchers say that extensive modelling shows a four degree temperature rise will be the threshold beyond which CO2 will start to increase more rapidly, as natural carbon ‘sinks’ of global vegetation become “saturated” and unable to sequester any more CO2 from the Earth’s atmosphere.
They call for a “change in research priorities” away from the broad-stroke production of plants and towards carbon ‘residence time’ – which is little understood – and the interaction of different kinds of vegetation in ecosystems such as carbon sinks.
Carbon sinks are natural systems that drain and store CO2 from the atmosphere, with vegetation providing many of the key sinks that help chemically balance the world – such as the Amazon rainforest and the vast, circumpolar Boreal forest.
As the world continues to warm, consequent events such as Boreal forest fires and mid-latitude droughts will release increasing amounts of carbon into the atmosphere – pushing temperatures ever higher.
Initially, higher atmospheric CO2 will encourage plant growth as more CO2 stimulates photosynthesis, say researchers. But the impact of a warmer world through drought will start to negate this natural balance until it reaches a saturation point.
The modelling shows that global warming of four degrees will result in Earth’s vegetation becoming “dominated” by negative impacts – such as ‘moisture stress’, when plant cells have too little water – on a global scale.
Carbon-filled vegetation ‘sinks’ will likely become saturated at this point, they say, flat-lining further absorption of atmospheric CO2. Without such major natural CO2 drains, atmospheric carbon will start to increase more rapidly – driving further climate change.
The researchers say that, in light of the new evidence, scientific focus must shift away from productivity outputs – the generation of biological material – and towards the “mechanistic levels” of vegetation function, such as how plant populations interact and how different types of photosyntheses will react to temperature escalation.
Particular attention needs to be paid to the varying rates of carbon ‘residence time’ across the spectrum of flora in major carbon sinks – and how this impacts the “carbon turnover”, they say.
The Cambridge research, led by Dr Andrew Friend from the University’s Department of Geography, is part of the ‘Inter-Sectoral Impact Model Intercomparison Project’ (ISI-MIP) – a unique community-driven effort to bring research on climate change impacts to a new level, with the first wave of research published today in a special issue of the journal Proceedings of the National Academy of Sciences.
“Global vegetation contains large carbon reserves that are vulnerable to climate change, and so will determine future atmospheric CO2,” said Friend, lead author of this paper. “The impacts of climate on vegetation will affect biodiversity and ecosystem status around the world.”
“This work pulls together all the latest understanding of climate change and its impacts on global vegetation – it really captures our understanding at the global level.”
The ISI-MIP team used seven global vegetation models, including Hybrid – the model that Friend has been honing for fifteen years – and the latest IPCC (Intergovernmental Panel on Climate Change) modelling. These were run exhaustively using supercomputers – including Cambridge’s own Darwin computer, which can easily accomplish overnight what would take a PC months – to create simulations of future scenarios:
“We use data to work out the mathematics of how the plant grows – how it photosynthesises, takes-up carbon and nitrogen, competes with other plants, and is affected by soil nutrients and water – and we do this for different vegetation types,” explained Friend.
“The whole of the land surface is understood in 2,500 km2 portions. We then input real climate data up to the present and look at what might happen every 30 minutes right up until 2099.”
While there are differences in the outcomes of some of the models, most concur that the amount of time carbon lingers in vegetation is the key issue, and that global warming of four degrees or more – currently predicted by the end of this century – marks the point at which carbon in vegetation reaches capacity.
“In heatwaves, ecosystems can emit more CO2 than they absorb from the atmosphere,” said Friend. “We saw this in the 2003 European heatwave when temperatures rose six degrees above average – and the amount of CO2 produced was sufficient to reverse the effect of four years of net ecosystem carbon sequestration.”
For Friend, this research should feed into policy: “To make policy you need to understand the impact of decisions.
“The idea here is to understand at what point the increase in global temperature starts to have serious effects across all the sectors, so that policy makers can weigh up impacts of allowing emissions to go above a certain level, and what mitigation strategies are necessary.”
The ISI-MIP team is coordinated by the Potsdam Institute for Climate Impact Research in Germany and the International Institute for Applied Systems Analysis in Austria, and involves two-dozen research groups from eight countries.
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“As the world continues to warm, consequent events such as Boreal forest fires and mid-latitude droughts will release increasing amounts of carbon into the atmosphere – pushing temperatures ever higher.
Initially, higher atmospheric CO2 will encourage plant growth as more CO2 stimulates photosynthesis, say researchers. But the impact of a warmer world through drought will start to negate this natural balance until it reaches a saturation point”
To get the results they wanted, these clowns had to make several several bad assumptions.
1. That global temperatures will increase much more than what any credible evidence shows.
2. That droughts and boreal forest fires will increase, again with no legit evidence
3. That increasing temperatures and CO2 will adversely effect plants when studies show that plants do better under warmer temperatures when CO2 levels are doubled.
Elevated CO2 Helps Reduce the Negative Impacts of High Temperatures on Plant Growth:
“the optimum temperature for plant growth and development has typically been found to rise right along with the air’s CO2 content. For a 300-ppm increase in atmospheric CO2, for example, theoretical and observational studies have shown that the optimum temperatures of most C3 plants rise by approximately 5°C for such a CO2 increase. This rise in optimum temperature is even larger than the rise in air temperature predicted to result from the greenhouse effect of such a CO2 increase. Consequently, it is clear that a CO2-induced warming would not adversely affect the vast majority of Earth’s plants; for fully 95% of them are of the C3 variety”
http://www.plantsneedco2.org/default.aspx?menuitemid=342
Increasing CO2 without question increases vegetative growth. This increase, also leads to bigger contributions from plant respiration to low level moisture during the growing season at mid latititudes. This factor decreases droughts.
Deserts are in drought all the time. It gets very hot there during much of the year/Summer. What has happened in deserts when we increased CO2 in the real world?…………
“Deserts ‘Greening’ from Rising Carbon Dioxide: Green Foliage Boosted Across the World’s Arid Regions”
http://www.sciencedaily.com/releases/2013/07/130708103521.htm
This measured effect is 180 degrees, the complete opposite of what this study claims will happen………….and they probably spent months taking money to come up with this nonsense.
I am sure I have read a bigger bunch of malarkey, but it must have been a while ago as I don’t recall it. Why does anyone let this sort of “my computer model says it is so” heifer dust get into a journal? (well it would be ok in a sci-fi journal)
And to the guys arguing about how long some CO2 that went into the atmosphere because I burned some steaks on the grill — none of you know how long that bit of CO2 will stay in the atmosphere and stop pretending you do. No one does. I do know that 400 ppm is a trace gas and that man’s minor addition to that is a trace of a trace.
This whole CO2 will kill life on earth crap is getting very tiresome.
Stupidity annoys me. All this talk of 4 degree rise has no reality because there is no warming. They like to call the current cessation of warming a “hiatus” which it is not. There is more carbon dioxide in the air than ever before but there has not been any greenhouse warming this is supposed to cause for the last fifteen years. The absence of greenhouse warming, the life blood of the alleged “anthropogenic global warming” for this length of time is sufficient to tell me as a scientist that it does not exist. That wonderful idea that Svante Arrhenius presented, of the doubling of carbon dioxide changing the climate, is simply wrong. But this is not all. The actual documented cessation of warming has lasted 33 years, not 15 years because because we must add an 18 year stretch from the eighties and nineties. The reason you don’t know about it is that official temperature curves covered it up with a bogus “late twentieth century warming.” Doing research for my book “What Warming?” I proved that this warming did not exist and even put a warning about it into the preface of the book. Nothing happened for two years but then the big three of temperature – GISTEMP, HadCRUT, and NCDC, decided , in unison, not to show this warming any more. What they did was to line up their data for this period with satellites which do not have this fake warming. It was done secretly and no explanation was given. The explanation is that my book exposed their scam. What we have now is two periods of no-warming, The two stretches of no-warming are separated only by the super El Nino of 1998 and its accompanying step warming. It is that step warming, caused by the warm water carried over by the super El Nino and not by CO2, that raised all twenty-first century temperatures above the twentieth. Hansen and his acolytes keep claiming that carbon dioxide did it which shows how ignorant they are of real climate science.
If co2 drops to 200 to 300 ppm then human beings quit breathing . If co2 drops to 160 to 180 ppm then vegetation starts dying and mammals also starts dying. .Compliments of the scientific ignorance of CAGW groups.
The amazin’ power of parameter plugs proven once again!
Aside from the obvious residence time plug, they also have the water cycle effect inverted. Cool air holds less moisture, leading to droughts, while warm holds more and increases precipitation. Witness the “Carboniferous” climate.
The planet has mostly been completed forested for the past, let’s say, 180 million years (since Pangea broke apart and the large deserts in its interior disappeared).
Then 2 things happened.
C4 grasses evolved about 24 million years ago. This then established a new vegetation biome on Earth which allowed a more active Carbon Cycle to develop and CO2 levels dropped below 280 ppm, for perhaps the very first time.
The planet remained completely forested (well except for Antarctica). In fact, 10 million years ago, 50 different species of Apes lived in these forests. It really was the “planet of the Apes” at this time. 50 species of large mammals is domination.
Then, 8 million years ago, something happened which changed the Earth’s climate so that there was less precipitation and the forests started to die back in colder regions and in dryer regions. Perhaps it got that just little bit colder. Instead of +2.0C, it was only +1.5C.
C4 grasses expanded exponentially and we have the appearance of savanna grasslands and open areas for the first time since Pangea. C4 grasses are more efficient in dryer and hotter areas and replace the C3 trees and bushes. One of those 50 species of Ape decided to develop upright walking to navigate the open savanna regions and we evolved as a result although it took another 7.5 million years.
Then the ice ages started up about 2.7 million years ago. Precipitation fell during the glacial cycles so that grassland and tundra and desert became more common on the planet than forested areas. At the last glacial maximum, only the US southeast was forested. The rest was grassland, or glacier or tundra or desert. CO2? 185 ppm.
CO2 seems to have played no part in these changes at all. It is evolution/Carbon Cycle and precipitation which falls as it gets colder (and rises as it gets warmer). There are certain latitudes which develop deserts if a large landmass is present (Sahara, Pangea monster deserts) but this is geographic/a rotating planet with an atmosphere/low temperature related).
Regarding the carbon residence time. It is actually irrelevant because carbon dioxide is not warming the world (see my other comment). But rather than trust modeling and hypothetical warming that will not happen, we can use observations. There are two sets of observations that are relevant. The first is the measured decay of atmospheric carbon-14 following the cessation of atmospheric nuclear testing in the twentieth century. These observations give a carbon residence time of 10 years or less. The second data source is the Keeling curve. It is sensitive enough to show the yearly wiggle caused by loss and regrowth of leaves on deciduous trees. One result based on this wiggle gives a residence time of about seven years. Both of these could be revisited and refined if the global warming establishment can spare some of the hundreds of millions of dollars they waste on trying to prove a non-existent warming. Forget about the effect of the hypothetical changes predicted by their models that are worthless.
dborth says:
December 16, 2013 at 2:54 pm
Just watched a good portion of the Discovery Channel (Canada/UK) production “Earth from Space”. It was actually pleasantly short on the doom being perpetuated by the human species in the planet – in favour of describing the many complex mechanisms that have created climate stability – and thus protected life – for several billion years.
—
Note the show was reproduced by PBS for its Nova series – available on YouTube – sorry I don’t know how to insert the link.
http://youtu.be/38peWm76l-U
“The researchers say that, in light of the new evidence, scientific focus must shift away from productivity outputs – the generation of biological material – and towards the “mechanistic levels” of vegetation function, such as how plant populations interact and how different types of photosyntheses will react to temperature escalation.”
For the one Bazillionth time, you must understand that model runs, simulations, do not and cannot produce evidence.
Instead, you should say that what you know about biomass absorption of CO2 on planet Earth allows you to create scenarios on supercomputers and that the scenarios show that four degrees of warming is the tipping point, given that your assumptions in the scenarios are reasonable on scientific grounds. Simulations cannot produce scientific grounds. It follows, then, that your first task is to present arguments to the effect that your assumptions are reasonable on scientific grounds.
Bill Illis on December 16, 2013 at 4:08 pm
The planet has mostly been completed forested for the past, let’s say, 180 million years (since Pangea broke apart and the large deserts in its interior disappeared).
Then 2 things happened.
Treasure this knowledge that Bill Illis brings us. Many in the AGW scam are working to achieve the extinction of such knowledge.
Duster says:
December 16, 2013 at 2:28 pm
and
Bill Illis says:
December 16, 2013 at 4:08 pm
Great geological arm waving (and it fits the geological history). There is so much more to this wonderful planet than CO2, but at some point (as in diamond mines and life on earth as we know it) the stuff is important. Just not so much in controlling the temperature of the Earth.
Here is an email I just got from CLIMATE SOLUTIONS:
http://hosted.verticalresponse.com/1306731/6c30777434/544497633/c6699a950c/
“””Today is the 350th day of 2013 and an incredibly urgent time for our climate. In just the last few weeks, we’ve seen the terrible and heartbreaking costs of massive climate disruption worldwide and at our backdoor. We’re up against incredibly well-funded industries that want to keep business as usual. Yet business as usual will mean we destroy the planet.
I have friends asking me: is it too late? No. We can build a better world for our children. But we are the last generation that has a chance to address the climate crisis and this must be our legacy. That’s where you come in. You understand what is at stake and how little time we have to reverse this trend. This year, we surpassed unprecedented atmospheric carbon dioxide levels of 400 ppm for the first time when the consensus among climate scientists is that the safe upper limit is 350 ppm.
Today, on the 350th day of 2013, can you chip in $350, $100, $35 or more? We are less than $7,000 away from our December 31st goal of $75,000 to launch a new climate action initiative.”””
WOWSA…
It’s too early to celebrate. Note that between 1977 and 2000 the trend was also essentially 0 for the annual global temperature.
@zeke
I appreciate you trying to explain co2 residence time but your link is really basic stuff and super general. For example, what happens to the co2 I am exhaling in my house? I highly doubt any of these molecules is making it to the ocean, based upon where I live. And the co2 isn’t just lingering in the air, otherwise I would be dead. I’m just not seeing the long residence time, how do you justify the IPCC deviating from the peer reviewed literature on it? Secondly, we know throughout geologic history that deserts had once been tropical paradise such as the Sahara. The late Ordovician period had an atmospheric co2 concentration around 4400ppm and there were glaciers, the GAT at this point was similar to today’s. So if the earth can do that naturally, how can you possibly believe the manmade influence is more powerful than the natural? If you think humanity can prevent things like this in the future, why aren’t you promoting terraforming?
BW2013 says:
December 16, 2013 at 5:35 pm
Today, on the 350th day of 2013, can you chip in $350, $100, $35 or more? We are less than $7,000 away from our December 31st goal of $75,000 to launch a new climate action initiative.”””
===============
And what is this climate initiative you might ask? Why of course to get our asses out of this cold winter weather and off to some tropical paradise where we can spend the day’s sipping Mai-tai’s with the local hotties. Please give generously.
OK, I did not say that personally!! That came from CLIMATE SOLUTIONS.
.
BW2013 says:
December 16, 2013 at 5:35 pm
This year, we surpassed unprecedented atmospheric carbon dioxide levels of 400 ppm for the first time when the consensus among climate scientists is that the safe upper limit is 350 ppm.
===========
Too late. Were all dead. Might as well kill yourself.
Zeke writes “I wrote a brief article a few years back that might be helpful:”
Well I’m pretty sceptical about the paper your article is based on, Zeke. Its widely believed that the ocean provides around half the O2 and therefore marine based photosyntheesis is a very large part of the cycle.
fwiw the wiki states “The tiny marine cyanobacterium Prochlorococcus was discovered in 1986 and accounts for more than half of the photosynthesis of the open ocean”
http://en.wikipedia.org/wiki/Oxygen_cycle
And yet your paper says the following about the ocean’s role in absorbing CO2 wrt life “An implicit scheme is used to compute CO2 gas exchange over the annual time step, as biological activity alters the carbon chemistry of surface waters.”
With no supporting reference. What “implicit scheme” one might ask? And how does it vary with temperature wrt that biological activity? The whole paper pretty much ignores life as far as I can see and concentrates on the chemical processes involved. Its no wonder it predicts a slow sequestration rate…
BW2013 says:
December 16, 2013 at 6:03 pm
OK, I did not say that personally!! That came from CLIMATE SOLUTIONS.
=====
nuff said. just having fun and giving you the credit.
TimTheToolMan says:
December 16, 2013 at 6:09 pm
The whole paper pretty much ignores life as far as I can see and concentrates on the chemical processes involved. Its no wonder it predicts a slow sequestration rate…
==========
You hit the nail on the head. Microscopic life calls the shots. It is why CO2 sequestration varies as a function of the annual excess. Inorganic models predict that sequestration varies as the the total excess and assume that it is simply coincidence that sequestration remains firmly fixed at 1/2 of annual excess, even though annual excess is taking off like a rocket with China’s growth. Life predicts that sequestration will vary as the source inputs, and the cumulative excess will simply be co-incidence.
“The researchers say that, in light of the new evidence”— What evidence is that? The article was discussing what it clearly stated was a model. I’m not a jurist, but I’ve some experience as a Legal Officer when I was still in the Navy, and a model is NOT evidence. Were that the case, I could “prove” someone committed a crime with a re-enactment. Rot. A Model demonstrates how I believe my theory works. It is an explanation. It is NOT evidence of ANYTHING except my own pet aflatus.
To go a bit further, while the model apparently looks at vegetation as if it’s the ONLY thing in the biosphere that reacts with CO2, it ignores all sea life and it’s interactions with CO2 during this increase in temperature, it ignores all chemical reactions at the increased temperatures with the Earth’s crust, it doesn’t even admit that there are other things to consider outside of this pet theory about plants. I don’t recall any studies that show that vegetation has behaved this way in the past, and they reference none in the article. Did they research any to corroborate their model?
I gotta ask: is it just me, or does it appear to anyone else that these guys are getting desperate and grasping at straws?
Warmer temperatures will lead to more rain not less. The last couple of million years confirm this.
The Potsdam Institute should be closed. They have no quality science to offer..
@ur momisugly Rob Potter
“The simplistic idea that warmer equals drier is the complete opposite of the basic CAGW meme that CO2 effect in the atmosphere is amplified by the increased water vapour which it causes.”
—————————————
Gee, Rob. Everyone knows that AGW causes droughts, floods, warming, cooling, pause, no pause, smaller animals, bigger animals, less vegetation, more vegetation, more snow, less snow, …………strokes, hemorrhoids, migraine, gangrene, diarrhea, constipation, round kidney stones, square kidney stones and rolling stones. ; ))
How can they have such a detailed discussion on CO2 and plants while totally ignoring that the vast majority of the CO2 is dissolved in the oceans and would certainly cook out a fair bit with a four deg C increase in temperature? The oceans would swamp out any plant-based changes. These people are discussing the color of a mouse’s fur while a snake is busy eating it.
I posted my calculation of atmospheric CO2 lifetime in this WUWT thread:
http://wattsupwiththat.com/2013/12/11/co2-residence-times-take-two/
My results: Time constant of 20 years, halflife of 14 years in the past several years. Also, I have looked at the bomb test results before, and it appears to me that ocean sinking decreased after the warming acceleration in the 1970s.
Not that I see atmospheric lifetime of CO2 increasing from 14 years halflife soon, now that we have a warming hiatus that appears to me as likely to continue for roughly 20 more years. Also, I don’t see ocean sinking stopping due to saturation, since solubility of a gas in a liquid varies directly, usually close to proportionately, with the concentration of the gas above the liquid. The atmospheric halflife of CO2 appears to me likely to increase once the sun bottoms out from a likely short and deep dip in activity, maybe in the 2030s. However, I still see halflife of atmospheric CO2 in excess of equilibrium with top ocean waters not getting much past 20 years.
As for equilibrium with ocean far enough down to not have had CO2 content significantly increased, that is longer. I remember having calculated a few years ago something in the 3-5 decade class.
Rather than taking their output from questionable computer models, why don’t they build their own (CEAS) Controlled Environment Agriculture Center to see what would happen to their plants if they raised the temp 4 degrees and decreased the artificial rainfall. The stomata in plants have amazing abilities to compensate.