That’s the good news. The bad news is that they think it will take 30,000-40,000 years, even though they “don’t know exactly where this carbon went” (their own words from the press release) in their model. Isn’t it great when you can announce results like that and not have to worry about tracking where the main component went?
And I thought Susan Solomon’s 1000 year CO2 regime was way out there.
Purdue-led team studies Earth’s recovery from prehistoric global warming
WEST LAFAYETTE, Ind. – The Earth may be able to recover from rising carbon dioxide emissions faster than previously thought, according to evidence from a prehistoric event analyzed by a Purdue University-led team.
When faced with high levels of atmospheric carbon dioxide and rising temperatures 56 million years ago, the Earth increased its ability to pull carbon from the air. This led to a recovery that was quicker than anticipated by many models of the carbon cycle – though still on the order of tens of thousands of years, said Gabriel Bowen, the associate professor of earth and atmospheric sciences who led the study.
“We found that more than half of the added carbon dioxide was pulled from the atmosphere within 30,000 to 40,000 years, which is one-third of the time span previously thought,” said Bowen, who also is a member of the Purdue Climate Change Research Center. “We still don’t know exactly where this carbon went, but the evidence suggests it was a much more dynamic response than traditional models represent.”
Bowen worked with James Zachos, a professor of earth and planetary sciences at the University of California, Santa Cruz, to study the end of the Palaeocene-Eocene Thermal Maximum, an approximately 170,000-year-long period of global warming that has many features in common with the world’s current situation, he said.
“During this prehistoric event billions of tons of carbon was released into the ocean, atmosphere and biosphere, causing warming of about 5 degrees Celsius,” Bowen said. “This is a good analog for the carbon being released from fossil fuels today.”
Scientists have known of this prehistoric event for 20 years, but how the system recovered and returned to normal atmospheric levels has remained a mystery.
Bowen and Zachos examined samples of marine and terrestrial sediments deposited throughout the event. The team measured the levels of two different types of carbon atoms, the isotopes carbon-12 and carbon-13. The ratio of these isotopes changes as carbon dioxide is drawn from or added to the atmosphere during the growth or decay of organic matter.
Plants prefer carbon-12 during photosynthesis, and when they accelerate their uptake of carbon dioxide it shifts the carbon isotope ratio in the atmosphere. This shift is then reflected in the carbon isotopes present in rock minerals formed by reactions involving atmospheric carbon dioxide, Bowen said.
“The rate of the carbon isotope change in rock minerals tells us how rapidly the carbon dioxide was pulled from the atmosphere,” he said. “We can see the fluxes of carbon dioxide in to and out of the atmosphere. At the beginning of the event we see a shift indicating that a lot of organic-derived carbon dioxide had been added to the atmosphere, and at the end of the event we see a shift indicating that a lot of carbon dioxide was taken up as organic carbon and thus removed from the atmosphere.”
A paper detailing the team’s National Science Foundation-funded work was published in Nature Geoscience.
It had been thought that a slow and fairly constant recovery began soon after excess carbon entered the atmosphere and that the weathering of rocks, called silicate weathering, dictated the timing of the response.
Atmospheric carbon dioxide that reacts with silicon-based minerals in rocks is pulled from the air and captured in the end product of the reaction. This mechanism has a fairly direct correlation with the amount of carbon dioxide in the atmosphere and occurs relatively slowly, Bowen said.
The changes Bowen and Zachos found during the Palaeocene-Eocene Thermal Maximum went beyond the effects expected from silicate weathering, he said.
“It seems there was actually a long period of higher levels of atmospheric carbon dioxide followed by a short and rapid recovery to normal levels,” he said. “During the recovery, the rate at which carbon was pulled from the atmosphere was an order of magnitude greater than the slow drawdown of carbon expected from silicate weathering alone.”
A rapid growth of the biosphere, with a spread of forests, plants and carbon-rich soils to take in the excess carbon dioxide, could explain the quick recovery, Bowen said.
“Expansion of the biosphere is one plausible mechanism for the rapid recovery, but in order to take up this much carbon in forests and soils there must have first been a massive depletion of these carbon stocks,” he said. “We don’t currently know where all the carbon that caused this event came from, and our results suggest the troubling possibility that widespread decay or burning of large parts of the continental biosphere may have been involved.”
Release from a different source, such as volcanoes or sea floor sediments, may have started the event, he said.
“The release of carbon from the biosphere may have occurred as a positive feedback to the warming,” Bowen said. “The forests may have dried out, which can lead to die off and forest fires. If we take the Earth’s future climate to a place where that feedback starts to happen we could see accelerated rates of climate change.”
The team continues to work on new models of the carbon cycle and is also investigating changes in the water cycle during the Palaeocene-Eocene Thermal Maximum.
“We need to figure out where the carbon went all those years ago to know where it could go in the future,” he said. “These findings show that the Earth’s response is much more dynamic than we thought and highlight the importance of feedback loops in the carbon cycle.”
Related website:
Purdue Isotope Ratio Ecology and Hydrology:
http://www.eas.purdue.edu/ireh/index.htm
Press release and abstract on the research in this release is available at: http://www.purdue.edu/newsroom/research/2011/110421BowenCarbon.html
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The earth doesn’t need to ‘recover’ from anything. CO2 goes up, plants flourish, species adapt, live evolves. CO2 goes down, plants decline, species adapt, life evolves. CO2 in the atmosphere is a phenomenon, not a problem.
And breathe…
Recovery is worse than they thought!
Are there any bids on models that purport to predict 50,000 years into the future? Going once, twice …
Oh well could give the Abiogenic petroleum theory a reboot. :-/
Can I now cancel the ice house venue booked for my 30,000th birthday with confidence?
What do these people mean-‘recover from rising CO2’ ?
Geohistorically atmospheric CO2 levels have been much higher than today. The average, if such a number were to be important, would be much higher than today. Considering the fact that plant growth will increase with more atmospheric CO2 then today’s paltry volume is required to increase.
The CO2 sinks include that for the formation of limestones which is a process that has been running for billions of years resulting in limestone being the most prolific of sedimentary rocks and depleting the atmosphere of a vital life giving gas.
If we want to feed everyone to a satisfactory level then more atmospheric CO2 is needed. (see the latest post on the co2science site about raddish growth in a CO2 enriched atmosphere).
Wouldn’t have something to do with all those thick Eocene coal deposits around the world perhaps? The ultimate carbon dioxide filter.
As luck would have it, that 30,000 years will put us smack in the middle of the next ice age, and we won’t be able to tell for sure if they’re right or wrong. Darn warmistas always give themselves an out.
So they seem to saying in effect that CO2 cycles are natural, levels go up which then kicks off an increased absorption cycle. What we have then is a dynamic robust biosphere system with the ability to respond to natural cyclic changes.
You can infer, although I guess they would never say it, that there is no problem with CO2 and there will not be a problem with CO2 as we just happen to live on a planet with robust evolved systems able to cope with atmospheric changes.
Let me summarize their work: Do not worry, there is no problem, there never was a problem, all the thousands of scaremongering stories about a fragile earth just about to die because of supposed feedbacks.
The pro-AGW set loves the PETM, because all kinds of simulations can be produced about it.
The evidence indicates CO2 increased by an amount which would be equivalent to about 3,000 Gigatonnes of Carbon versus human’s yearly contribution of about 10.0 Gigtonnes today. CO2 levels stayed high for 170,000 years.
The likely source of the CO2 was north Atlantic volcanoes. The north Atlantic was just opening up at the time and a large magma plume between Europe and Greenland (which were attached at the time) started the split and the opening of the north Atlantic. Magma plumes typically last between 100,000 years and 1.0 million years, so CO2 was constantly being added over time as individual eruptions occurred.
Comments:
– The pro-AGW set builds their simulations assuming that the CO2 was added in one single event, instantaneously that is – but nobody knows how much CO2 was released by these volcanoes, how long it took and was there, in fact, 50,000 Gigatonnes of CO2 released over multiple events covering 165,000 years, which were rapidly sequestered by oceans and plants each individual time.
– the only high resolution data at the start of the event says that temperatures increased first, about 3,000 years before the CO2 increase started.
– the PETM was not that warm and it was not that special. It was 4C warmer 30 million years earlier when CO2 was only half as high. The pro-AGW set likes to focus on it because it is the only time in Earth history when a CO2 increase occurred at the same time as a temperature increase.
– Today, plants and oceans are absorbing about 2.0% of the excess CO2 above 280 ppm each year. Applying the same framework to the PETM CO2 levels means that the CO2 was rapidly sequestered after each volcanic event. Then another large volcano went off in the north Atlantic and so on and so on.
– All kind of “simulations” can be done around an event such as this.
even though they “don’t know exactly where this carbon went” (their own words from the press release)Perhaps the Fern did it?
See http://en.wikipedia.org/wiki/Azolla_event
I thought that the expected time constant of co2 in the atmosphere was 50 years, based on the amount the level currently is above pre-industrial levels and the proportion of mankind’s emissions that disappear from the atmosphere. These guys are saying it only takes 30000 years. Somebody better tell the warmists so they can say that each amount of co2 emitted will take 30000 years to disappear.
So it only takes a little longer to get CO2 to absorb into a colder earth than it does to get logic through the thick skulls of Orthodox scientists. Again, the ice-core isotopes show that CO2 does not affect temperature in any significant way, but temperature evidently controls CO2. And yes, decreasing temperature leads decreasing CO2 by the order of 10,000 years after thermal optima.
If they really wanted to look at a huge C shift, 5000 to 500 ppm, ~425-325MYA was much more dramatic. ‘Normal’ levels over the past .5 billion years is closer to 2500 ppm.
http://i55.tinypic.com/11awzg8.jpg and here http://i46.tinypic.com/2582sg6.jpg
In the article they write:-
“During this prehistoric event billions of tons of carbon was released into the ocean, atmosphere and biosphere, causing warming of about 5 degrees Celsius,” Bowen said. “This is a good analog for the carbon being released from fossil fuels today.”
What an extraordinary claim to make.
Do they have proof that this prehistoric event which released billions of tons of carbon caused the 5 degrees rise?
There may have been a 5 degree Celsius rise, but they can only theorise as to the cause. Whereas they seem to be stating that they know there is a direct link. There are so many variables that are simply unknown to be able to do anything else but theorise as to the cause.
Why would this be a good analog for today?
When will they understand that Carbon Dioxide and Warming is beneficial for the biosphere.
“When faced with high levels of atmospheric carbon dioxide and rising temperatures 56 million years ago, the Earth increased its ability to pull carbon from the air.”
Yes, but next time it might decide not to, then where will we be?
There are three categories of knowledge:
1 what we know
2 what we don’t know
3 what we don’t know we don’t know.
This study adds to our category 2 knowledge, which makes it slightly better than most other climatology studies. I know of none that have provided category 1 knowledge. If you do, I seek enlightenment.
““We need to figure out where the carbon went all those years ago to know where it could go in the future,” he said”
As long as you do it on your own dime, and not mine, go for it.
Happy earth day. Save the trees. The trees and grassies inhale CO2 . It is their diet.
Plants scrub the atmosphere.
“During this prehistoric event billions of tons of carbon was released into the ocean, atmosphere and biosphere, causing warming of about 5 degrees Celsius,” Bowen said.
So diamonds cause warming? Graphite causes warming? Carbon is an element these people are misusing words intentionally to continue a falsehood.
Quicker than anticipated from carbon models?! That seems backwards and upside down to me when actual is considered to be “off” compared to some model. More like proof that they don’t understand and can’t explain reality. There: I fixed the conclusion part of the study.
I don’t care for the common inferences from the term “recover” either. Come to think of it, “recover” may not even scientfically describe what is going on except in the crudest meaning of returning to a prior measurement level. It looks like publicity was a consideration in bringing this “study” to market.
Perhaps the natural course for an earth-like planet, sans a life form intelligent enough to manipulate the environment, is to deplete itself of CO2 through uncontrolled plant growth which would eventually lead to the death of those very plants and in the end leave a cold, lifeless world. Perhaps it is we, the evil humans, who have unwittingly saved our own planet from this fate.
My visit here this morning started with great anticipation of good science and then I read Gabriel’s model crap. Another model and lots of “it seems” and “it is thought” kind of speculation. The never ending story of agw grant graspers.
How long was the peer-review cycle from submission to publication for this 30,000-40,000 CO2 recovery cycle?
Basil Beamish:
April 22, 2011 at 4:29 am
Maybe. Seems like when sea levels are low there are lots of coals deposited. And when sea levels are high, there are lots of limestones.
From what I understand, aren’t the Mauna Loa measurements only detecting about half the CO2 in the atmosphere expected based upon the fossile fuel combustion. If that is the case, wouldn’t it be much more prudent to first sort out the mass balance and find the sink (likely in the oceans, precipitating out as carbonate minerals) and then try to figure out what might happen in 30K years?