Releases may have speeded end of last ice age — and could act again![[]](https://i0.wp.com/www.eurekalert.org/images/clear.gif?resize=8%2C1){kind=spacer}
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IMAGE: This pictures shows the locations of cores showing Antarctic upwelling.
Natural releases of carbon dioxide from the Southern Ocean due to shifting wind patterns could have amplified global warming at the end of the last ice age–and could be repeated as manmade warming proceeds, a new paper in the journal Science suggests.
Many scientists think that the end of the last ice age was triggered by a change in Earth’s orbit that caused the northern part of the planet to warm. This partial climate shift was accompanied by rising levels of the greenhouse gas CO2, ice core records show, which could have intensified the warming around the globe. A team of scientists at Columbia University’s Lamont-Doherty Earth Observatory now offers one explanation for the mysterious rise in CO2: the orbital shift triggered a southward displacement in westerly winds, which caused heavy mixing in the Southern Ocean around Antarctica, pumping dissolved carbon dioxide from the water into the air.
“The faster the ocean turns over, the more deep water rises to the surface to release CO2,” said lead author Robert Anderson, a geochemist at Lamont-Doherty. “It’s this rate of overturning that regulates CO2 in the atmosphere.” In the last 40 years, the winds have shifted south much as they did 17,000 years ago, said Anderson. If they end up venting more CO2 into the air, manmade warming underway now could be intensified.
Scientists have been studying the oceans for more than 25 years to understand their influence on CO2 levels and the glacial cycles that have periodically heated and chilled the planet for more than 600,000 years. Ice cores show that the ends of other ice ages also were marked by rises in CO2.
Two years ago, J.R. Toggweiler, a scientist at the National Oceanic and Atmospheric Administration (NOAA), proposed that westerly winds in the Southern Ocean around Antarctica may have undergone a major shift at the end of the last ice age. This shift would have raised more CO2-rich deep water to the surface, and thus amplified warming already taking place due to the earth’s new orbital position. Anderson and his colleagues are the first to test that theory by studying sediments from the bottom of the Southern Ocean to measure the rate of overturning.
The scientists say that changes in the westerlies may have been triggered by two competing events in the northern hemisphere about 17,000 years ago. The earth’s orbit shifted, causing more sunlight to fall in the north, partially melting the ice sheets that then covered parts of the United States, Canada and Europe. Paradoxically, the melting may also have spurred sea-ice formation in the North Atlantic Ocean, creating a cooling effect there. Both events would have caused the westerly winds to shift south, toward the Southern Ocean. The winds simultaneously warmed Antarctica and stirred the waters around it. The resulting upwelling of CO2 would have caused the entire globe to heat.
Anderson and his colleagues measured the rate of upwelling by analyzing sediment cores from the Southern Ocean. When deep water is vented, it brings not only CO2 to the surface but nutrients. Phytoplankton consume the extra nutrients and multiply.
In the cores, Anderson and his colleagues say spikes in plankton growth between roughly 17,000 years ago and 10,000 years ago indicate added upwelling. By comparing those spikes with ice core records, the scientists realized the added upwelling coincided with hotter temperatures in Antarctica as well as rising CO2 levels.
In the same issue of Science, Toggweiler writes a column commenting on the work. “Now I think this really starts to lock up how the CO2 changed globally,” he said in an interview. “Here’s a mechanism that can explain the warming of Antarctica and the rise in CO2. It’s being forced by the north, via this change in the winds.”
At least one model supports the evidence. Richard Matear, a researcher at Australia’s Commonwealth Scientific and Industrial Research Organisation, describes a scenario in which winds shift south and produce an increase in CO2 venting in the Southern Ocean. Plants, which incorporate CO2 during photosynthesis, are unable to absorb all the added nutrients, causing atmospheric CO2 to rise.
Some other climate models disagree. In those used by the Intergovernmental Panel on Climate Change, the westerly winds do not simply shift north-south. “It’s more complicated than this,” said Axel Timmermann, a climate modeler at the University of Hawaii. Even if the winds did shift south, Timmermann argues, upwelling in the Southern Ocean would not have raised CO2 levels in the air. Instead, he says, the intensification of the westerlies would have increased upwelling and plant growth in the Southeastern Pacific, and this would have absorbed enough atmospheric CO2 to compensate for the added upwelling in the Southern Ocean.
“Differences among model results illustrate a critical need for further research,” said Anderson. These, include “measurements that document the ongoing physical and biogeochemical changes in the Southern Ocean, and improvements in the models used to simulate these processes and project their impact on atmospheric CO2 levels over the next century.”
Anderson says that if his theory is correct, the impact of upwelling “will be dwarfed by the accelerating rate at which humans are burning fossil fuels.” But, he said, “It could well be large enough to offset some of the mitigation strategies that are being proposed to counteract rising CO2, so it should not be neglected.”
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Firstly, I’m sceptical that NH ice extent can have a substantial effect on the latitude of SH near polar winds as it would require the tropical climate zone to be pushed well south of the equator.
Secondly, it doesn’t get around the CO2 rises following, and not before, temperature increases problem (for the Warmers).
Thirdly, one thing we know for sure about the start and end of glacial cycles is there is a large change in the land covered in ice/snow and hence added or removed from the biosphere (and carbon cycle), and most of that land is in the NH. Occams Razor says this is the primary cause of the CO2 changes.
In other news, Bjorn Lomborg says Global Warming will save millions of lives!
Bjorn Lomborg
Did you see the conclusions of the Denmark meeting – BBC newscast today March 12, 2009 – of AGW scientists saying that global warming is proceeding at twice the rate of forecast warming of earlier years (probably can find this story in a number of places including BBC website). I think the hoary winters of the last couple of years have created a desperation to ensure no doubts arise in Obama’s carbon policies – N America is the only holdout remaining.
Noodling the aardvarks could have accelerated the positive feedback of the anthropological Jim-jams. I’ll need a research grant to further investigate this important finding.
Stephen Wilde, can you give a direct link to your jetstream analysis. TIA
Hasn’t Dr. Lindzen stated that he is of the opinion that any further increase in CO2 would have virtually no effect at this point? Does it really matter how much more there is beyond a certain amount? Forgive me for not citing the reference… I know I saw a quote from Dr. Lindzen around here somewhere recently.
Well “May” and “Could” are the authors of more papers on climate than any other famous scientists; so when you see a paper by May & Could you should give it the proper respect it deserves.
We are told that during ice ages, the ocean levels have dropped dramatically; hundreds of feet. Something has to supply all the water to make that land ice pile. when that ice up finally melts, and the sea rises several hundred feet, one May & Could get disturbances of deeper waters, but I don’t see why it wouold be any more turbulent than at any other time; assuming that it doesn’t happen over night.
I’ll just wait until May & Could publish some of their obsevational data on the phenomenon, when it next happens.
The ice cores tell us that the CO2 rises come about 800 years after the surface temperature rises. Where in that time frame would this wind shift process occur.
It would be nice if these chaps would simply point to the recent shifts that caused the CO2 rise now being measured at Mauna Loa and elsewhere.
“Many scientists think that the end of the last ice age was triggered by a change in Earth’s orbit that caused the northern part of the planet to warm”
Where is the explanation of this supposed change in Earth’s orbit? Quite a grand assumption quickly passed over.
A better scenario to me is that approx 15,000 years ago Earth’s obliquity was heading towards maximum while eccentricity was decreasing and the NH summer solstice was heading towards perihelion. This combination increases summer NH solar insolation enough to cause the glaciers to start the retreat. And the rest they say is history.
Now here’s a really great line:- “”” Anderson says that if his theory is correct, the impact of upwelling “will be dwarfed by the accelerating rate at which humans are burning fossil fuels.” But, he said, “It could well be large enough to offset some of the mitigation strategies that are being proposed to counteract rising CO2, so it should not be neglected.” “””
Fancy that; IF his theory is correct, it will [STILL] be dwarfed by… humans burning fossil fuels…. which as last reported, has so far not led to ANY observable warming or other catastrophe.
So evidently according to May & Could, a completely non-event like human fossil fuel burning still dwarfs their newly found discovery of Maybe & Coulbe CO2 increase forom ending ice ages.
Wow aren’t we all happy to learn that the end of the next ice age will be much less than a non event. Well they said it; not me !
Same scam, different theory, same BS (Bad Science).
The red threat of the whole story, First comes the CO2, then comes the warming.
I don’t buy it.
Jae
Re chicken and egg. The egg came first, as the thing that laid it was not a chicken. Basic evolutionary theory.
George E. Smith (12:59:26) :
I would be really surpized that those models include the 800 years delay in CO2 concentration change.
Are there other sources of CO2 other than water, snow/ice, volcano and biomass combustion that is usually released after a glaciation period?
On that biomass combustion topic, as we know, it takes time for the biomass to build up after a glaciation period. By the same way, lightnings are rare in winter (but of course there are not any biomass to burn in the first place on ice). But once there is a good size biomass that is regrowing and chances of fires increase with time, could that be also an important source of CO2 to be added?
Couldn’t such an upwelling of CO2 rich and therefore less alkaline water be responsible for the reduced surface alkalinity they are already using as the next big scare tactic to encourage us to live in serfdom?
“Up to”, “from”, “may” and “could”
these are the words that mean we should,
be very careful to believe
words that aim to deceive.
So be careful
as you should
when you see the words
“up to”, “from”, “may” and “could”.
Fashion models are by far nicer than these apocalyptic “models”
Philip_B
This is probably the best one to start with although many of my articles refer to it.
You may find the build up a bit long but it is necessary for the lay reader. The jet stream analysis is towards the end.
http://climaterealists.com/attachments/database/The%20Unifying%20Theory%20Of%20Earths%20Climate__0__0__1231443918.pdf
I hope you enjoy the read and thank you for your interest.
Start with a BS assumption (CO2 is the prime driver of global warming), then proceed to ask the question – “how can I come up with a believable mechanism that proves this?” Well, they failed here, as they always will when they start with the BS and try to justify it.
Whatever happened to starting with an unexplained observation, then proceeding to the great question, “so what?”.
How about an arctic warm enough for semi-tropical turtles and yet no runaway venus global warming death destruction:
http://www.msnbc.msn.com/id/29550126/
So it was significantly hotter than now and the net result was a tropical paradise in the equatorial / temperate zone and an arctic rather like Carolina… Somehow I don’t think my Canadian friends would mind too much.
I wish I could remember who linked a few days ago to a paper from Germany, but I went and read it. Very, very good! The paper applies basic physics to the entire notion of AGW driven by CO2. There are some places where one could quibble, but on the whole the paper (long..115 pages) is excellent.
Two of the main points: the AGW hypothesis consistently mistakes absorption/re-radiation for reflection. However, the main “kicker’ is that the entire hypothesis violates the 2nd Law by claiming the atmosphere (cooler medium) can heat the surface (a warmer medium) without additional work input. i.e. the AGW idea is a perpetual motion machine.
Gerlich and Tscheuschner, “Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics”
arXiv:0707.1161v4 [physics.ao-ph] 4 Mar 2009
“Differences among model results illustrate a critical need for further research,” said Anderson.
I believe this just illustrates what the AGW crowd really is after – more research = more $$$ and no real work is needed – just slightly conflicting studies to keep the game going.
What complete and utter drivel!
Oh the humanity!
For the counter argument that any increase in CO2 is offset by changes in the earths precipitation systems which then leads to no net effect on global temperature, see:
http://landshape.org/enm/greenhouse-effect-in-semi-transparent-planetary-atmospheres-by-miskolczi-a-review/
“The climate system makes regulatory adjustment to compensate for changes in CO2 with changes in humidity and clouds, in order to most efficiently convert short wave incoming solar energy, into long wave outgoing energy. The problem with radiative models used until now is a discontinuity between the atmospheric and surface temperatures. This violates Kirchhoff’s law, that two bodies in thermal equilibrium must have equal temperatures, and is one of the reasons for mysterious unphysical behavior of climate models. Incorporating this simple constraint introduces an energy minimization principle that makes runaway greenhouse warming impossible. This corrects a major deficiency in the current theory, which doesn’t explain why “runaway” greenhouse warming hasn’t happened in the Earth’s past.”
And this:
http://miskolczi.webs.com/
I’m with Tom from Florida in regard to the “orbit shif” issue. The thesis presented in the article is completely dependent upon there having been a shift in the earth’s orbit. No orbit shift means there was no change in the wind dirctionand so no release of CO2 and no warming and no need to be concerned about climate models. Is there any evidence in the geologic record of any shift in the earth’s record at any time in the past billion or so years? And if the proposed shift did indeed occur, wouldn’t it be expected to have consequences well beyomd that of changing wind patterns?
“Anderson says that if his theory is correct, the impact of upwelling “will be dwarfed by the accelerating rate at which humans are burning fossil fuels.” But, he said, “It could well be large enough to offset some of the mitigation strategies that are being proposed to counteract rising CO2, so it should not be neglected.””
Hey, he said dwarfed; didn’t he mean “little peopled”?
So, we need to stop using all fossil fuels posthaste, which will kill millions
of people bringing populations down to sustainable levels. We then need
to switch to windmills and wooden shoes immediately! Where do they find
these guys? God, I’m so tired of the relentless drum beat of stupidity!
OT, the Lost Angeles Times today has a fear-mongering SEAS ARE RISING story.
A quote: “Ice sheet melting has since accelerated [since mid-1990’s projections from IPCC]. Dan Cayan, a researcher at the Scripps Institution of Oceanography and a lead scientist on the state’s action plan, said the 55-inch estimate in the report is “probably conservative. . . . As temperature climbs, melting is going to proceed at a greater pace. It is not necessarily going to proceed linearly, in the same proportion as it did in the past, because melting begets more melting.”
http://www.latimes.com/news/local/la-me-global-warming-searise12-2009mar12,0,2741152.story