Thawing permafrost 50 million years ago led to extreme global warming events

Apr 04, 2012
This is thawing permafrost on the North Slope along the Sagavanirktok River near Deadhorse, Alaska. Credit: Courtesy of Kevin Schaefer of the National Snow and Ice Data Center, University of Colorado Boulder

In a new study reported in Nature, climate scientist Rob DeConto of the University of Massachusetts Amherst and colleagues elsewhere propose a simple new mechanism to explain the source of carbon that fed a series of extreme warming events about 55 million years ago, the Paleocene-Eocene Thermal Maximum (PETM), and a sequence of similar, smaller warming events afterward.

"The standard hypothesis has been that the source of carbon was in the ocean, in the form of gas in ocean-floor sediments," DeConto says. "We are instead ascribing the to the continents, in polar latitudes where permafrost can store massive amounts of carbon that can be released as CO2 when the permafrost thaws."

The new view is supported by calculations estimating interactions of variables such as greenhouse gas levels, changes in the Earth's tilt and orbit, ancient distributions of vegetation, and carbon stored in rocks and in .

While the amounts of carbon involved in the ancient soil-thaw scenarios was likely much greater than today, implications of the study appear dire for the long-term future as polar permafrost carbon deposits have begun to thaw due to burning fossil-fuels, DeConto adds. "Similar dynamics are at play today. Global warming is degrading permafrost in the north polar regions, thawing frozen organic matter, which will decay to release CO2 and methane into the atmosphere. This will only exacerbate future warming in a positive feedback loop."

He and colleagues at Yale, the University of Colorado, Penn State, the University of Urbino, Italy, and the University of Sheffield, U.K., designed an ―elusive up to now―to satisfactorily account for the source, magnitude and timing of carbon release at the PETM and subsequent very warm periods, which now appear to have been triggered by changes in the Earth's orbit.

Earth's atmospheric temperature is a result of energy input from the sun minus what escapes back to space. Carbon dioxide in the atmosphere absorbs and traps heat that would otherwise return to space. The PETM was accompanied by a massive carbon input to the atmosphere, with ocean acidification, and was characterized by a global temperature rise of about 5 degrees C in a few thousand years, the researchers point out. Until now, it has been difficult to account for the massive amounts of carbon required to cause such dramatic global warming events.

To build the new model, DeConto's team used a new, high-precision geologic record from rocks in central Italy to show that the PETM and other hyperthermals occurred during periods when Earth's orbit around the sun was both highly eccentric (non-circular) and oblique (tilted). Orbit affects the amount, location and seasonality of solar radiation received on Earth, which in turn affects the seasons, particularly in polar latitudes, where permafrost and stored carbon can accumulate.

They then simulated climate-ecosystem-soil interactions, accounting for gradually rising greenhouse gases and polar temperatures plus the combined effects of changes in Earth orbit. Their results show that the magnitude and timing of the PETM and subsequent hyperthermals can be explained by the orbitally triggered decomposition of soil organic carbon in the circum-Arctic and Antarctica.

This massive carbon reservoir at the poles "had the potential to repeatedly release thousands of petagrams of carbon to the atmosphere-ocean system once a long-term warming threshold was reached just prior to the PETM," DeConto and colleagues say. Until now, Antarctica, which today is covered by kilometers of ice, has not been appreciated as an important player in such global carbon dynamics.

In the past, "Antarctica and high elevations of the circum-Arctic were suitable locations for massive carbon storage," they add. "During long-term warming, these environments eventually reached a climatic threshold," with permafrost thaw and the sudden release of stored soil carbon triggered during the Earth's highly eccentric orbits coupled with high tilt.

The model described in the paper also provides a mechanism that helps to explain relatively rapid recovery from hyperthermals associated with orbital extremes occurring about every 1.2 million years, which had until now been difficult.

Overall, they conclude, "an orbital-permafrost soil mechanism provides a unifying model accounting for the salient features of the hyperthermals that other previously proposed mechanisms fail to explain." Further, if the analysis is correct and past extreme warm events can be attributed to permafrost loss, it implies that thawing of permafrost in similar environments observed today "will provide a substantial positive feedback to future warming."

Explore further: Researchers resolve the Karakoram glacier anomaly, a cold case of climate science

More information: www.nature.com/nature/journal/… ull/nature10929.html

Provided by University of Massachusetts at Amherst

4.3 /5 (28 votes)

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Shootist
2 / 5 (29) Apr 04, 2012
Thawing permafrost 50 million years ago led to extreme global warming events


Actually the warming started before the permafrost melted . . .

And, 15My later Antarctica froze over. Who 'da thunk it?
Gustav
1.7 / 5 (23) Apr 04, 2012
Exactly... For whatever reason more sunlight reached the ocean's surface, CO2 dissolved in the ocean water outgassed. A simple chain of events. The ocean warms up first, CO2 follows. The same has been happening in the late 20th century. Permafrost does release gasses on melting, but I doubt this has much effect on temperatures. It does not affect the Venus atmosphere one bit, which when measured from the top down to the level matching that of the earth atmospheric pressure has the same profile as that of the earth merely corrected for a closer distance to the sun and well described by the barometric formula.
Vendicar_Decarian
3.9 / 5 (29) Apr 04, 2012
The melting of permafrost on Venus is not a common occurrence given that Venus has the surface temperature of liquid lead.

Perhaps Venus has permafrost in some alternate realities, but just not here in the reality based community.

"Permafrost does release gasses on melting, but I doubt this has much effect on temperatures. It does not affect the Venus atmosphere one bit..."
NotParker
1.8 / 5 (26) Apr 04, 2012
"Global temperatures rose by about 6 °C (11 °F) over a period of approximately 20,000 years.

That is a 0.0003 °C (.00055 °F) increase per year. "

OMG!!!!! CO2 is .... impotent.
jscroft
1.3 / 5 (25) Apr 04, 2012
Hey, ScottTard: Instead of focusing on Gustav's throw-away comment, why not address Shootist's very important point?

Never mind. We know why.
rubberman
4.1 / 5 (21) Apr 04, 2012
Hey, ScottTard: Instead of focusing on Gustav's throw-away comment, why not address Shootist's very important point?

Never mind. We know why.


Pretty simple dude. The reason a warming event can last 200,000 (this is the estimated length of that particular warm period)years is due to excess GHG's in the atmosphere, otherwise all warming events would end when the parameters that iniated the warming disappeared. The MWP and Roman warm periods lasted hundreds of years...CO2 PPM never climbed above 290. PETM...estimates range from 1000PPM to higher....hence a 200,000 year warm period.

NP...got a link for us on this one...can't wait!
NotParker
1.6 / 5 (21) Apr 04, 2012
http://en.wikiped..._Maximum

"all warming events would end when the parameters that iniated the warming disappeared."

CO2 rose 100ppm during the Eemian. Eemian ended.

CO2 never stops warming from ending.

In fact, it is an amazingly impotent GHG.
StillWind
1.8 / 5 (21) Apr 04, 2012

Perhaps Venus has permafrost in some alternate realities, but just not here in the reality based community.


Actually, in the "reality based community", we know that CO2 doesn't really affects Venus, either. Those who suggest that it does, really just ignores how any body is heated in space. Although it might support your fantasy scenario, it has nothing to do with physics.

Try again.
NotParker
1.6 / 5 (25) Apr 04, 2012
Oh Oh. Warming first. Then CO2.

"Here we show that continental warming of about 5°C preceded the CIE in the Bighorn Basin, Wyoming. Our evidence, based on oxygen isotopes in mammal teeth (which reflect temperature-sensitive fractionation processes) and other proxies, reveals a marked temperature increase directly below the CIE, and again in the CIE. Pre-CIE warming is also supported by a negative amplification of 13C values in soil carbonates below the CIE. Our results suggest that at least two sources of warmingthe earlier of which is unlikely to have been methanecontributed to the PETM."

http://www.nature...441.html
Vendicar_Decarian
4 / 5 (16) Apr 04, 2012
"In fact, it (CO2) is an amazingly impotent GHG." - ParkerTard

The relatively pleasant global climate of the last 10,000 years is largely thanks to higher levels of atmospheric carbon dioxide.

http://www.scient...-ice-age
thermodynamics
4.8 / 5 (17) Apr 04, 2012
NP: How do you measure "impotent GHG?" What is your figure of merit? If you look at the spectral signature of CO2 and H2O you will find that CO2 covers areas that H2O does not. So, it is filling the gaps. Yes, it absorbs less than H2O, but it also absorbs in the gaps between H2O lines. So, as H2O starts to maximize what it can absorb the CO2 fills in and starts absorbing what the H2O cannot. That is the reason the two gases tend to positively reinforce the actions of each other. If they both absorbed at the same exact lines there would be considerably more interference than there is. Please explain your comment in some way other than "amazingly impotent."
NotParker
1.7 / 5 (23) Apr 04, 2012
The relatively pleasant global climate of the last 10,000 years is largely thanks to higher levels of atmospheric carbon dioxide.


"As a resultand for reasons that remain unexplainedthe waters of the Southern Ocean may have begun to release carbon dioxide"

Right. A Magic Unexplained CO2 release.

"The reason for the retreat of the ice sheets remains elusive, however."

Ahhh. More Magic.

Shall we call this the Magic Unicorn Theory?
NotParker
1.6 / 5 (25) Apr 04, 2012
How do you measure "impotent GHG?"


Did CO2 prevent the Eemian from ending? No.

Did CO2 cause the Holocene Optimum? Minoan? Roman? MWP? No.

Is 1950 the date when CO2 effects were supposed to be noticeable?

Did it warmer faster and higher 1910 to 1944 (before 1950)? Yes.

Did Co2 drop after 1998? No. Then why did the warming stop?
NotParker
1.8 / 5 (26) Apr 04, 2012
Another laugher from Nature ...

"The melting in the north could have been triggered "because the ice sheets had reached such a size that they had become unstable and were ready to go." "

What? Big ice sheets are unstable and collapse all on their own?

That is dumber than VD and a sack of hammers combined!
DKA
4.6 / 5 (8) Apr 04, 2012
Not Parker, I agree with you, Co2 rise is really causing global warming. Whoever still come up with odd and stranger arguements to denie it are really dumb and need to go back to school, unlike you and me.
Telekinetic
4.3 / 5 (19) Apr 04, 2012
Why is it so difficult for the global warming denier to accept a simple fact as stated in the article- "implications of the study appear dire for the long-term future as polar permafrost carbon deposits have begun to thaw due to burning fossil-fuels"? It can only be due to being raised in an atmosphere of such piggishness and love of money that they would equate any restriction of business to murder. The global warming denier is a capitalist of the worst kind, he sees money-making opportunities in the collapse of the planet.
eachus
1.9 / 5 (9) Apr 05, 2012
Why is it so difficult for the global warming denier to accept a simple fact as stated in the article- "implications of the study appear dire for the long-term future as polar permafrost carbon deposits have begun to thaw due to burning fossil-fuels"?


Perhaps because they have learned that simple theories are usually wrong? In this particular case, why did melting of the permafrost cause it to release CO2, instead of plants growing in the now unfrozen soil, sequestering CO2? There may be an answer to my question, but it is not found here.

Much, much more important, what happens if we dump some grass seed on the permafrost that is melting now? That is an experiment I would like to see tried with some sterile seed to get answers before accidentally changing the environment. (Think rabbits in Australia, or zebra mussels in the Great Lakes.)
axemaster
5 / 5 (5) Apr 05, 2012
Man, what the heck is wrong with the edit function? It keeps erasing half of my comment...
axemaster
4.8 / 5 (16) Apr 05, 2012
Actually the warming started before the permafrost melted...
-Shootist

Amazing, he figured out that ice melts due to heat.

Permafrost does release gasses on melting, but I doubt this has much effect on temperatures.
-Gustav

CO2 is .... impotent... In fact, it is an amazingly impotent GHG.
-NotParker

Huh, that's strange. There's a mountain of evidence showing that it is actually fairly potent, even without any feedbacks. In fact, the correlation is something like .9C/100ppm CO2. And that's ignoring the thermal inertia due to the heat capacity of the planet, meaning the real figure is higher. Source: http://moregrumbi...ure.html

Did Co2 drop after 1998? No. Then why did the warming stop?
-NotParker

Since you refuse to learn even the base rudiments of statistics, let me draw some rough error bounds on this global temp graph. http://i1210.phot...igA2.png
Parsec
5 / 5 (12) Apr 05, 2012
Why is it so difficult for the global warming denier to accept a simple fact as stated in the article- "implications of the study appear dire for the long-term future as polar permafrost carbon deposits have begun to thaw due to burning fossil-fuels"?


Perhaps because they have learned that simple theories are usually wrong? In this particular case, why did melting of the permafrost cause it to release CO2, instead of plants growing in the now unfrozen soil, sequestering CO2? There may be an answer to my question, but it is not found here.

Much, much more important, what happens if we dump some grass seed on the permafrost that is melting now? That is an experiment I would like to see tried with some sterile seed to get answers before accidentally changing the environment. (Think rabbits in Australia, or zebra mussels in the Great Lakes.)

Its quite easy to measure CO2 and CH4 emissions from melting permafrost. We have and there is a lot.
Argiod
3.3 / 5 (14) Apr 05, 2012
If you think that CO2 is impotent; try breathing it some time.
Russkiycremepuff
1 / 5 (12) Apr 05, 2012
So, from all the threads I've read about CO2 caused by AGW, the only reason for polar ice melts, etc. is CO2 caused by AGW, and not by the Sun or undersea hydrothermals. That is some powerful stuff, that AGW. But what is the solution to this amazing AGW? Does anyone have the answer besides genocide, eugenics, or asking for voluntary suicides? You people sure do talk a lot, but none of you give any good solutions.
Maybe a lot of governmental interference in peoples' lives? How about placing video cameras in all the rooms in everyone's home to see if they're being environmentally friendly? PLEASE, will someone give some good answers to this perceived danger to the world?
Stop jawing with your fingers and think about what should be done. When will the governments start the killings?
Without providing solutions, your credibility is disappearing.
NotParker
1.5 / 5 (17) Apr 05, 2012
If you think that CO2 is impotent; try breathing it some time.


Yeah. And exhale it .... and breath it and ...

Hey wait. I do that all the time.
NotParker
1.3 / 5 (17) Apr 05, 2012
Why is it so difficult for the global warming denier to accept a simple fact


Because the next ice age will arrive. No matter what. It would be the most massively lucky thing if CO2 prevented the end of the Holocene.

Try and remember the Eemian was so warm there were Hippo's in the UK.

The Eemian ended.

http://www.njgonl...icle.pdf
Howhot
4.3 / 5 (12) Apr 05, 2012
The Eemian ended. YOW! Like when did that happen? I think government owes me for it. Just kidding. Well just think about it for a moment, 20,000 years from now, with nothing alive except heat resistant bacteria on desolated planet and that will be known as the Post Human Age.

http://www.youtub...O__NFKEA

Have fun!
NotParker
1.3 / 5 (15) Apr 05, 2012
20,000 years from now ...


... this planet will be about 20,000 years into the next ice age.
Howhot
5 / 5 (10) Apr 05, 2012
LOL; Your a shill.
... this planet will be about 20,000 years into the next ice age.


And you got this information from WHO?

kaasinees
2.5 / 5 (11) Apr 05, 2012
http://www.youtub...O__NFKEA

Have fun!


Oh god videos like those and the comments on it make me embarrased to be human...

And i need a new expression to replace "oh god"
Howhot
5 / 5 (9) Apr 06, 2012
kaa; Lol... Yes sometimes you need to hear the crazy to understand the crazy. Somebody needed to break the ice on this argument.

BS is what it is. Sometimes you need to spread it around.
Vendicar_Decarian
4.2 / 5 (5) Apr 06, 2012
SoylentGrin
1 / 5 (2) Apr 07, 2012
Interesting...
Axemaster gave a link to a chart that shows anomalous cooling starting about the mid-1940's, then jumping back up sharply.

http://i1210.phot...igA2.png

Then there's this that shows that sulfur can "mask" warming trends for a short period:

http://www.upi.co...9979567/

How much sulfur was thrown into the air during WWII from gunpowder?
NotParker
1.3 / 5 (12) Apr 07, 2012

How much sulfur was thrown into the air during WWII from gunpowder?


Fair question. However this paper is an attempt to quantify SO2 emissions.

http://www.certi-...ions.pdf

You can see SO2 rose from 1933 to 1945, then a big drop as the wartime industry stopped making ships/tanks/bombers. And then a very steep climb until about 1980 when I suspect some of the clean air legislation kicked and/or when places like the UK and US stopped burning coal at home.
MorituriMax
1 / 5 (4) Apr 07, 2012
Golly, I wonder how the critters living back then managed to reverse the warming?
Lurker2358
2.5 / 5 (8) Apr 08, 2012
Golly, I wonder how the critters living back then managed to reverse the warming?


A super volcano releases enough sulfur and iron into the air to cool the planet by sequestering carbon in the ocean and ice, while blocking out the Sun.

Unfortunately, when this happens, it usually kills a large percentage of all life forms on the planet.

You can check long term CO2 data from core samples and compare to long term data from the ejecta and ash of volcanoes, and the times where CO2 drops catastrophically always corresponds immediately to a VEI 7 or 8 volcano.

Adapt or die, plus a "change up" kills much things.

Everything is forced to adapt to a ridiculously hot planet, and then when the next volcano or meteor happens, it is suddenly forced to adapt to a ridiculously cold planet.
NotParker
1 / 5 (7) Apr 08, 2012

A super volcano releases enough sulfur and iron into the air to cool the planet by sequestering carbon in the ocean and ice, while blocking out the Sun.


Unfortunately, Yellowstone last erupted 630,000 years ago ... and erupts every 600,000 years give or take.

http://www.barry....ONE.html
axemaster
5 / 5 (4) Apr 08, 2012

A super volcano releases enough sulfur and iron into the air to cool the planet by sequestering carbon in the ocean and ice, while blocking out the Sun.


Unfortunately, Yellowstone last erupted 630,000 years ago ... and erupts every 600,000 years give or take.

http://www.barry....ONE.html

Dear lord, what is that thing you're using as a source?! Aliens and prophecies? What on earth are you thinking? Plus some of the data there is wrong. Better figures from USGS (United States Geological Survey) indicate it last "supererupted" 640,000 years ago, and the interval is 600,000 - 800,000 years. Plus there have also been 80 smaller eruptions since the last major one.
Source: http://volcanoes....tory.php
axemaster
5 / 5 (4) Apr 08, 2012
Also I would point out the following remarks from the USGS:

Is it true that the next caldera-forming eruption of Yellowstone is overdue?

No. First of all, one cannot present recurrence intervals based on only two values. It would be statistically meaningless.

So there you are. Source: http://volcanoes....uptagain

So, NotParker, when are you planning to learn statistics? It really isn't too hard if you possess basic knowledge of arithmetic and common sense... all you have to do is pick up a textbook for a few hours. Really. It's that easy.
NotParker
1 / 5 (7) Apr 08, 2012
My source said 630,000. Yours say 640,000.

"The Huckleberry Ridge Tuff was followed by the Mesa Falls Tuff (1.3 million years ago) and the Lava Creek Tuff (0.63 million years ago)."

"three eruptive pulses 150,000 years ago, 110,000 years ago and 70,000 years ago"

NotParker
1 / 5 (8) Apr 08, 2012
USGS:

"But for those who insist... let's do the arithmetic. The three eruptions occurred 2.1 million, 1.3 million and 0.64 million years ago. The two intervals are thus 0.8 and 0.66 million years, averaging to a 0.73 million-year interval. Again, the last eruption was 0.64 million years ago, implying that we are still about 90,000 years away from the time when we might consider calling Yellowstone overdue for another caldera-forming eruption. Nevertheless, we cannot discount the possibility of another such eruption occurring some time in the future, given Yellowstone's volcanic history and the continued presence of magma beneath the Yellowstone caldera."

Note that the eruptions are getting closer together.
axemaster
4 / 5 (4) Apr 08, 2012
You... really don't get it, do you?

You can't get an interval from only two or three events. You can't. It's statistically wrong, factually wrong. Saying "the eruptions are getting closer together" is meaningless.

I always thought that you were just a global warming ideologue, denying it for ideological reasons. But now I think I've come to understand the truth... that you are an idiot. Or something. I'm not sure what I should be thinking at this point...
kaasinees
2.3 / 5 (9) Apr 08, 2012
Volcanos dont have patterns, there are too many variables that change wildly as these variables also depend on other variables that change wildly. For instance the temperature of the ocean and air, the currents in the earth itself.

That is statistics an average of 500 000 could mean it can happen over a million years.
NotParker
1 / 5 (8) Apr 08, 2012
Why would you STD's embarrass yourself over this?

It has erupted many times before. It will erupt again. If humans are around it will cause massive disruption of civilization in most of the western US.

It could erupt tommorrow or 100,000 years from now.

But it will erupt.

Denying that it could erupt tomorrow is really idiotic. (And by tomorrow I mean next 1,000 years or actually tomorrow).

Toba is also dangerous.

http://en.wikiped...ake_Toba

NotParker
1 / 5 (7) Apr 08, 2012

Toba is also dangerous.

http://en.wikiped...ake_Toba



"The eruption lasted perhaps two weeks, but the ensuing "volcanic winter" resulted in a decrease in average global temperatures by 3.0 to 3.5 °C "

"The Toba caldera is the only supervolcano in existence that can be described as Yellowstone's "bigger" sister. "

"he last eruption had an estimated VEI 8 (described as "mega-colossal"), making it possibly the largest explosive volcanic eruption within the last 25 million years."

Nearly wiped out human beings.
axemaster
5 / 5 (3) Apr 09, 2012
Denying that it could erupt tomorrow is really idiotic. (And by tomorrow I mean next 1,000 years or actually tomorrow).

I never said that it couldn't erupt tomorrow. I objected to you saying things that were unsupportable by the facts and basic statistics. Claiming that it will erupt again within some specified amount of time or that the interval between eruptions is decreasing is simply wrong, and I was pointing it out as such. As usual, your response is to misinterpret my sources - in this case saying exactly the opposite thing my source was saying - and put up straw men.

Quit putting words in our mouths to retaliate whenever we point out the -numerous- failings in practically everything you say.
rubberman
3.7 / 5 (6) Apr 09, 2012
I feel your pain Axe....reading a string with an NP debate is always good for laugh though. It's like watching America's funniest home videos when some dumbass nuts himself...and they replay it 6 or 7 times.
NotParker
1 / 5 (7) Apr 09, 2012
your response is to misinterpret my sources


I quoted your sources.
alta
1 / 5 (3) Apr 10, 2012
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