A new paper in Nature suggests CO2 leads temperature, but has some serious problems

This is an attempt to redefine the graph made famous by Al Gore in An Inconvenient Truth that showed temperature leading CO2.

EDC

From a press release embargoed until 1PM EST 4/4:

Work that may clarify the relationship between carbon dioxide (CO2) levels and temperature at the end of the last ice age is presented in this week’s Nature. The study reveals that rising temperatures were preceded by CO2 increases during the last deglaciation, contrary to prior findings derived from ice cores that were thought to represent larger global patterns. These results support an important role for CO2 in driving global climate change.

Antarctic ice-core records indicate that CO2 may have influenced climate changes during the Pleistocene ice ages, which began around 2.6 million years ago and ended about 11,700 years ago. However, the exact role of CO2 in producing climate changes has remained unclear, partly because ice-core records only reflect local temperatures. To better understand the relationship between CO2 and global climate change, Jeremy Shakun and colleagues reconstruct global surface temperatures for the last deglaciation. They show that rising temperatures are correlated with, and generally lag behind, increasing levels of CO2.

The reconstructed global temperatures were produced using proxy records of temperature variability, such as those recorded in planktonic microorganisms. Anomalies in the correlations, such as in the Antarctic where the CO2 changes lag behind temperature, are explained by redistribution of heat between the Northern and Southern Hemispheres, the authors suggest.

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Here is the long form press release (h/t to junkscience.com):

Rising CO2 levels linked to global warming during last deglaciation

CORVALLIS, Ore. – Many scientists have long suspected that rising levels of carbon dioxide and the global warming that ended the last Ice Age were somehow linked, but establishing a clear cause-and-effect relationship between CO2 and global warming from the geologic record has remained difficult.

A new study, funded by the National Science Foundation and published in the journal Nature, identifies this relationship and provides compelling evidence that rising CO2 caused much of the global warming.

Lead author Jeremy Shakun, who conducted much of the research as a doctoral student at Oregon State University, said the key to understanding the role of CO2 is to reconstruct globally averaged temperature changes during the end of the last Ice Age, which contrasts with previous efforts that only compared local temperatures in Antarctica to carbon dioxide levels.

“Carbon dioxide has been suspected as an important factor in ending the last Ice Age, but its exact role has always been unclear because rising temperatures reflected in Antarctic ice cores came before rising levels of CO2,” said Shakun, who is a National Oceanic and Atmospheric Administration (NOAA) Post-doctoral Fellow at Harvard University and Columbia University.

“But if you reconstruct temperatures on a global scale – and not just examine Antarctic temperatures – it becomes apparent that the CO2 change slightly preceded much of the global warming, and this means the global greenhouse effect had an important role in driving up global temperatures and bringing the planet out of the last Ice Age,” Shakun added.

Here is what the researchers think happened.

Small changes in the Earth’s orbit around the sun affected the amount of sunlight striking the northern hemisphere, melting ice sheets that covered Canada and Europe. That fresh water flowed off of the continent into the Atlantic Ocean, where it formed a lid over the sinking end of the Atlantic Meridional Overturning Circulation – a part of a global network of currents that brings warm water up from the tropics and today keeps Europe temperate despite its high latitudes.

The ocean circulation warms the northern hemisphere at the expense of the south, the researchers say, but when the fresh water draining off the continent at the end of the last Ice Age entered the North Atlantic, it essentially put the brakes on the current and disrupted the delivery of heat to the northern latitudes.

“When the heat transport stops, it cools the north and heat builds up in the Southern Hemisphere,” Shakun said. “The Antarctic would have warmed rapidly, much faster than the time it takes to get CO2 out of the deep sea, where it was likely stored.

“The warming of the Southern Ocean may have shifted the winds as well as melted sea ice, and eventually drawn the CO2 out of the deep water, and released it into the atmosphere,” Shakun said. “That, in turn, would have amplified warming on a global scale.”

The researchers constructed a record of global surface temperature from 80 temperature reconstructions spanning the end of the Ice Age and found that average temperature around the Earth correlated with – and generally lagged behind – rising levels of CO2.

Peter Clark, an Oregon State University scientist and co-author on the paper, said changes in solar radiation were the likely trigger for the series of effects that followed. His 2009 study, published in Science, confirmed an earlier theory that wobble in the Earth’s axis, which changes the amount of sunlight captured by Earth, first caused melting of the large northern ice sheets.

“It has long been known that Earth’s slow wobble is caused primarily by the gravitational influences of the larger planets, such as Jupiter and Saturn, which pull and tug on the Earth in slightly different ways over periods of thousands of years,” said Clark, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences.

Shakun said there is “an enormous amount” of carbon sequestered in the deep ocean.

“The Southern Ocean is connected to all the deep ocean basins,” he pointed out, “so the most likely mechanisms to draw it out of the ocean were certainly there.”

The question now, the researchers say, is how human-generated carbon dioxide will affect the planet when there isn’t an ice age.

“CO2 was a big part of bringing the world out of the last Ice Age,” Shakun said, “and it took about 10,000 years to do it. Now CO2 levels are rising again, but this time an equivalent increase in CO2 has occurred in only about 200 years, and there are clear signs that the planet is already beginning to respond.”

“While many of the details of future climate change remain to be figured out, our study bolsters the consensus view that rising CO2 will lead to more global warming,” Shakun added.

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The paper is at http://www.nature.com/nature/journal/v484/n7392/full/nature10915.html and named:

Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation

Jeremy D. Shakun, Peter U. Clark, Feng He, Shaun A. Marcott, Alan C. Mix, Zhengyu Liu, Bette Otto-Bliesner, Andreas Schmittner & Edouard Bard

Abstract:

The covariation of carbon dioxide (CO2) concentration and temperature in Antarctic ice-core records suggests a close link between CO2 and climate during the Pleistocene ice ages. The role and relative importance of CO2 in producing these climate changes remains unclear, however, in part because the ice-core deuterium record reflects local rather than

global temperature. Here we construct a record of global surface temperature from 80 proxy records and show that temperature is correlated with and generally lags CO2 during the last (that is, the most recent) deglaciation. Differences between the respective temperature changes of the Northern Hemisphere and Southern Hemisphere parallel variations in the strength of the Atlantic meridional overturning circulation recorded in marine sediments. These observations, together with transient global climate model simulations, support the conclusion that an antiphased hemispheric temperature response to ocean circulation changes superimposed on globally in-phase warming driven by increasing CO2 concentrations is an explanation for much of the temperature change at the end of the most recent ice age.

METHODS SUMMARY

The data set compiled in this study contains most published high-resolution

(median resolution, 200 yr), well-dated (n5636 radiocarbon dates) temperature

records from the last deglaciation (see Supplementary Information for the full

database). Sixty-seven records are from the ocean and are interpreted to reflect sea

surface temperatures, and the remaining 13 record air or lake temperatures on

land. All records span 18–11 kyr ago and,85% of them span 22–6.5 kyr ago. We

recalibrated all radiocarbon dates with the IntCal04 calibration (Supplementary

Information) and converted proxy units to temperature using the reservoir corrections

and proxy calibrations suggested in the original publications. An exception

to this was the alkenone records, which were recalibrated with a global

core-top calibration41. The data were projected onto a 5u35u grid, linearly

interpolated to 100-yr resolution and combined as area-weighted averages. We

used Monte Carlo simulations to quantify pooled uncertainties in the age models

and proxy temperatures, although we do not account for analytical uncertainties

or uncertainties related to lack of global coverage and spatial bias in the data set. In

particular, the records are strongly biased towards ocean margins where high

sedimentation rates facilitate the development of high-resolution records. Given

these issues, we focus on the temporal evolution of temperature through the

deglaciation rather than on its amplitude of change. The global temperature stack

is not particularly sensitive to interpolation resolution, areal weighting, the

number of proxy records, radiocarbon calibration, infilling of missing data or

proxy type. Details on the experimental design of the transient model simulations

can be found in ref. 25.

The temperature stacks and proxy data set are available in Supplementary Information.

Full Methods and any associated references are available in the online version of

the paper at www.nature.com/nature.

PDF files

  1. Supplementary Information (9.2M)
    This file contains Supplementary Text and Data, Supplementary Figures 1-30, Supplementary Tables 1-3, additional References and Supplementary Appendices 1-2.

Excel files

  1. Supplementary Data (2.4M)
    This file contains Supplementary Data.

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Don Easterbrook has some initial thoughts on the Nature paper.

The paper is based on many assumptions without supporting data.  Here are a few examples:

1. They assume that CO2 is capable of causing climate changes, even though 95% of the greenhouse gas (GHG) effect is from water vapor. In order to seriously consider CO2 as a causal mechanism, you first need to prove that very tiny increases in CO2 do indeed increase atmospheric water vapor.  However, during recent warming, purported to be caused by increased CO2, atmospheric water vapor has not gone up, it has decreased slightly. CO2 by itself cannot cause significant warming because there is little of it in the atmosphere (0.038%) and CO2 accounts for only a few percent of the GHG effect.

2. They assume that the AMOC is the only driver of climate change, totally ignoring the influence of the Pacific Ocean, which covers almost half of the Earth’s surface and we can see in the modern data a strong influence of ENSO as a driver of climate changes (actually a closer correlation than the AMOC). They offer no evidence that the AMOC is the main and only driver of climate change.

3. They assume a hemispheric ‘see-saw’ of climate changes in which the North and South Hemispheres are out of phase, despite strong evidence in both hemisphere that climate changes were closely simultaneous, not out of phase with one another (Easterbrook, 2011).

4. The dismiss all other causal mechanisms by simply stating that they are only of ‘regional importance’, similar to the tactic of dismissing the MWP and Little Ice Age as only regional climate changes, not global. They also totally ignore the complete lack of correlation of CO2 with Holocene climate changes. They don’t even mention the very strong correlation of variation in 10Be and 14C with climate changes, suggesting a solar cause.

================================================================

The Antarctic Ice core graph is particularly troublesome.

Figure2

In the long scale graph at top, I pointed out that the resolution of the temperature reconstruction diminished as the sample got older. Willis responded to my query with this:

The resolution for temperature drops, as does the CO2 resolution, because the ice is getting more compressed and so there is more and more time between equally spaced samples. Here’s one of my old graphs of the same data, showing the same phenomenon:

co2-temp-willis

Where I think they go wrong is the claim that they can somehow reconstruct, not just the couple thousands of years of temperature that Mann claimed, but nearly a million years of temperature … and that the timelines for the two wouldn’t have errors.

My rule of thumb about these kinds of things is, no error bars … no science.

w.

Other rebuttals are in the works. I will add to this posting as they develop.

Pat Michaels writes to junkscience.com:

I am very unexcited about this. I have always thought that the timing of carbon dioxide changes and warming/cooling is pretty much irrelevant… What is interesting about this latest “finding” is that it demonstrates, yet again, the unfalsifiability of climate change “science”. The standard argument on the ice cores has been that temperature preceding carbon dioxide changes is simply evidence for positive feedback rather than lack of forcing. Now the argument will revert back to the other way around — that CO2 causes all the major pleistocene (which we are still in — see Greenland) climate fluctuations.

About that carbon dioxide–it’s just another attempt to explain the true mystery of climate change, which is why major glaciations ever go away.

My mantra is that “it’s not the heat, it’s the sensitivity”, which is obviously overestimated in climate models, for a variety of reasons that should be obvious.

Tom V. Segalstad Associated Professor of Resource and Environmental Geology, at the

University of Oslo writes:

There are some serious problems with ice cores.

I’ll be surprised if the new Nature paper cites our paper by Jaworowski,  Segalstad & Ono (1992): Do glaciers tell a true atmospheric CO2 story? in the professional peer-reviewed Elsevier journal “Science of the total  environment”, Vol. 114, pp. 227-284 (1992). The paper is available on my  website here: http://www.co2web.info/stoten92.pdf

There’s a follow-up paper (abstract) on the stable isotope temperature measurement technique in ice cores here: http://www.co2web.info/aig.pdf

I checked the references of the Shakun et al paper published today, and the paper Segalstad mentions is not part of the references section. I guess it was too inconvenient to mention.

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Michael T in Craster, UK

This is the BBC’s take on it. Oh boy, they just keep on trying…

Michael T in Craster, UK
cui bono

They could have saved themselves a lot of time and trouble by just using Mike’s Nature Trick (Mark 2) and shifting one set of data 1000 years to the left. 🙂

Latitude

I was under the impression that even main stream climate scientists ( I say that tongue in cheek) agreed that CO2 follows temps

Has the stench of desperate “results-driven” science ever been stronger? I’m amazed these “researchers” would stake their reputatons on finding some proxy, any proxy, to blur the 100-year lead of temperature-to-CO2 during the last deglaciation, when the multi-thousand-year lead from the previous glaciation (125,000 BC to 110,000 BC) so clearly exposes their sophistry.

It’s those farting Mammoths they keep digging up wot dunnit!

Doug Proctor

In many areas of science, what you see on the large scale, you see on the small scale, and vice-versa. It is a principle of geology and, I think, astrophysics, two ends of the spectrum. So if your long-term data shows a rise in temp before CO2, that is, the larger scale features of temp pre-date CO2 releases, then you will expect to see the same in the small scale. Which is what was first seen, the 800-year disconnect. “Adjusting” or “correcting” the data for the smaller time-frame to show the opposite is reasonable only if you also can do it for the larger time-frame.
The problem is this: how do you have small changes add up to become the bigger changes, if sums of each part are opposites? The small have to add up to the big.

mysteryseeker

This article is unreal!!!How on Earth can any conclusions be drawn as to what leads what when reliant on Antarctic ice cores, especially they are the very low resolution Vostok cores? The time it takes the gas, in this case Co2 to be sealed off from the present day atmospheric source is hundrends of years. This means is simple terms the resolution is just that poor. Nature magazine should know better! But they have an agenda, as scientists like Dr. Easterbrook and Dr. Roy Spencer well know! Rod Chilton, http//www.bcclimate.com

Interstellar Bill

The Models have Spoken. Dissent no more, ye Disbelievers.
Tremble at the destructive power of CO2.
Be it hereby revealed the True-Believers’ new mantra:
Climate Corrosion

wikeroy

So, what about Petit et al, Fisher et al and Callion et al ? Totally forgotten?

R. de Haan

A I have said before, they will never give up.

Gary

If CO2 leads temperatures, then what’s causing it to increase in the first place when the earth is very cold? Cold oceans tend to retain it. It’s not anthropogenic. Global respiration ought to be lower in glacial periods compared to inter-glacials. I can’t think of a source that would provide enough CO2 to force temperatures up, even if it truly was the driver.

R. de Haan

Of course the BBC is at it without any delay
http://www.bbc.co.uk/news/science-environment-17611404

mkelly

So their own graph shows that CO2 is nearly 400 ppm and the temperature now is less than the last interglacial and several past ones. How does that show CO2 is a driver of warmth?

George E. Smith;

Well I will have to read the paper in detail, and try to put actual dates to their data, such as what means the last deglaciation, but as to their overall conclusion, and specifically with reference to the first graph of 800,000 years of data in the first graph, my initial comment would be “poppycock”.
I’ll give just one observation; and you can easily see the repeats for yourself.
Looka t the spike upwards at around 120,000 years ago. Specifically look at the downward side of the CO2 and Temperature peaks. The CO2 decline is slow as all get out, compared to the much earlier and faster TEMPERATURE fall. No amount of mud snail prestidigitation can make that CO2 seem to fall before the Temperature decline that the lack of CO2 causes. They can try and fudge the rising edges all they want but you can look at every other peak in that sequence, and see that the CO2 declines later and much slower than the Temperature falls. And remember that is THEIR THESIS that the higher levels of CO2 is what is holding up the Temperature. And if the CO2 can’t hold up the Temperature in the Antarctic, where there are fewer competing distractions, it surely isn’t going to hold it up anywhere else.
I’ll let Don Easterbrook, have the genteel observations; my first reaction is, a lot of work for not much convincing. Balderdash, may be a more accurate evaluation of the claims. I’ll accept their “observations”, but the interpretation is full of holes.

bmcburney

So the first step in the process is that the Milankovitch cycle melts the ice but the melting of the ice is not a response to any increase in warmth because the change in the Milankovitch cycle itself does not increase warmth or produce climate change directly. The climate only warms once CO2 is released from the deep ocean which happens after the ice melts but before the climate warms in response to the CO2. The key insight of this paper is that the change in the Milankovitch cycle is a “climate neutral” event which melts the glaciers through an undisclosed process having nothing to do with climate.

cui bono

h/t to Michael T in Craster, UK (April 4, 2012 at 10:42 am) for the BBC link
“So, in the last 100 years we’ve gone up about 100 ppm – about the same as at the end of the last ice age, which I think puts it into perspective because it’s not a small amount.”
100 parts per million? Yes. It. Is.
PS: Where’s BBC doomspinmeister Richard Black? Somewhere discussing global warming policies (nudge nudge) with professor Kari Norgaard?

edcaryl

I thought we had already cast doubt on proxy temperature measurements?
http://wattsupwiththat.com/2012/04/03/proxy-science-and-proxy-pseudo-science/

kramer

I’ve always believed that ‘scientists’ were looking for a way to find CO2 leading temperature. And now they say they have…
My question is, the amount of rise in CO2 from those ice core graphs (about 100 ppm) only gives a few degrees of temp rise using the general CO2 warming equation of 5.2ln(c/co). If you look at how high the temperature changes, it changes by 10 to 12 degrees. What causes the other 8 to 10 degrees in temperature rise?

JFisk

Garys post is very interesting, what is causing the ancient CO2 rise?

Peter Miller

I suppose the one fact which nearly blew the top off my BSometer is this:
OK, but what caused the rising CO2 levels, which supposedly drove the temperature upwards?
The only realistic source is the oceans, which are not going to release the CO2 unless their temperatures rise. In other words, in order to have an egg, you first need a chicken, but where did the chicken come from etc.,etc.,
Someone suggested farting mammoths produced the increase in CO2, but even a ‘climate scientist’ would probably recognise this as being unlikely.
One possible explanation would be a huge increase in volcanic activity to explain the increase in carbon dioxide levels, but there is no evidence of that in the geological record.
A second explanation could be a huge increase in animal (including farting mammoths – although they died out before the Holocene began), insect and vegetation levels – the problem here is that you need the temperature to rise first to make the global climate more clement for life to thrive and begin exhaling more CO2.
So what are we left with?
1. Natural climate cycles warming the oceans and releasing CO2, and
2. Faulty data readings, analysis, or maybe even outright untruths and/or falsification of data.

Solomon Green

As I recollect EG Beck’s paper on the 180 year CO2 record was slated because it relied on local measurements which varied widely from location to location (probably due to pollution). I have never understood why Antarctic ice-core records should be considered suitable proxies for global CO2. How do modern Arctic readings compare with those of Mauna Loa? Has CO2 atmospheric penetration been measured consistently over a period in, say, a remote Antarctic area and, if so, how does that data relate to Mauna Loa’s?

Kev-in-Uk

As Gary says – it is illogical for increased CO2 before temp rises – about the only thing I could think of that would cause significant increased natural CO2 before temp rises would be volcanoes (obviously of the super dooper type) or perhaps mega amounts of acid rain falling on all the carbonate rocks releasing stored CO2! Neither seem very plausible on a global scale….

kramer

The BBC article somebody linked to above says
“At the end of the last ice age, CO2 rose from about 180 parts per million (ppm) in the atmosphere to about 260;
If you plug in those numbers to the general CO2 equation of dF = 5.35 ln(C/Co), you get:
1.967 (not sure of units, either K, C, or F)
According to many ice core temperature graphs I have seen, the temperature rise from the last ice age was 20 degrees F:
http://blogs.edf.org/climate411/2007/06/29/human_cause-3/
So unless I plugged in some wrong numbers or did a math error, how could a 80 ppm rise in CO2 give 20F of warming when their own warming equation gives 1.97 (which could be in C or K…)?

mwhite

This has appeared on the BBC
http://www.bbc.co.uk/news/science-environment-17611404
Dr Shakun’s team has now constructed a narrative to explain both what was happening on Antarctica and what was happening globally:
This starts with a subtle change in the Earth’s orbit around the Sun known as a Milankovitch “wobble”, which increases the amount of light reaching northern latitudes and triggers the collapse of the hemisphere’s great ice sheets
This in turn produces vast amounts of fresh water that enter the North Atlantic to upset ocean circulation
Heat at the equator that would normally be distributed northwards then backs up, raising temperatures in the Southern Hemisphere
This initiates further changes to atmospheric and ocean circulation, resulting in the Southern Ocean releasing CO2 from its waters
The rise in CO2 sets in train a global rise in temperature that pulls the whole Earth out of its glaciated state
I’ve read this a few times and all I see is, the warming starts first and the oceans get warmer.
Warmer water holds less gas than colder water
Dr Shakun’s narrative suggests that the warming precedes the rise in CO2 or am I losing it?

Over hundreds of millennia rising temperature always precedes rises in CO2.
I have several other charts from both hemispheres, all of which show CO2 rises after temperature rises. Either they are all wrong, or Shakun et al. are wrong.
I hate to be cynical [not really], but Jeremy Shakun seems to be in need of tenure. Mann tried to erase the LIA and the MWP. Now Shakun is trying to erase the very substantial ice core evidence showing that rises in CO2 follow rises in temperature, the same way that a Coke will outgas CO2 as it warms.

John F. Hultquist

. . . , but this time an equivalent increase in CO2 has occurred in only about 200 years, and there are clear signs . . .
During the last glacial the CO2 ppm was about 180. Then pre-industrial it went to about 280. So now at just under 400 it seems that is about an “equivalent increase” but a doubling would have it at 580 (and we are not there now and may never be). So based on the increase over the last 200 years there would be, then, a logarithmic response in temperature (or not). To the nearest whole number this comes out to be zero or maybe 1. And they see “clear signs.” Color me dubious.

Chris Colose

A quick general comment (and reply to Gary’s inquiry)
The paper does not claim that CO2 led everything going on, and you need to distinguish between Antarctic temperatures and global temperatures. A big point of this paper is that considerable spatial structure exists in the deglaciation process.
The *initial* cause centers around changes in orbital parameters (Milankovitch cycles) which then had an influence on the AMOC strength (and the bipolar seesaw, which has been documented in countless studies) ultimately warming Antarctica. Antarctic temperatures led CO2, but that does not apply to global temperatures (which lagged CO2 as you’d expect). The asymmetric bipolar seesaw response is antiphased between hemispheres, though superimposed on a global-mean warming.

Chris Colose:
1. CO2 is globally well mixed in the atmosphere
2. Arctic and Antarctic ΔT rises and falls in synch
3. Therefore, your assumption that rises in CO2 lead rises in T is wrong.

The Press Release BS says: “…identifies this relationship and provides compelling evidence that rising CO2 caused much of the global warming.” The Abstract says: “These observations, together with transient global climate model simulations, support the conclusion that an antiphased hemispheric temperature response to ocean circulation changes superimposed on globally in-phase warming driven by increasing CO2 concentrations is an explanation for much of the temperature change at the end of the most recent ice age.” Dennis says: “compelling my ass!” Dennis says, “indicating and supporting and or combined with other factors contributed to..and so on.” That is the best they can do, all any kind of modeling based on more assumptions that data can do. Lets at least be honest about what it is we think we know, would like to think we know, actually know and just out and out speculate about.

polistra

Now that this paper has taught me how heat and cold really work, I’m going to disconnect the thermostat from my house’s heating system, and instead use the temperature in Argentina to regulate my house. This will be much more appropriate.

FactChecker

I was trying to match this up against Murry Salby’s lecture from last year. What has become of that man and his is-it-published-yet paper?

tadchem

I feel compelled to point out what looks like a source of systematic error.
Is there anybody else that finds it VERY suspicious that the “CO2 concentration ppmv” curve and the “Antarctic temperature °C” curve mimic each other in about 24 peaks, over the entire temporal range, all the way down to relative timing AND relative magnitude?
It is almost like one was used for a proxy of the other *directly*, save for a 3 point-moving average data filter.
These 24 matching peaks, were they points on a fingerprint, would bring in a verdict of guilty in almost any US courtroom.

The last I checked the solubility of CO2 in water, although more complex than N2, is still inversely proportional to temperature, so I’m a bit lost with how CO2 precedes temperature increase if the assumption is all of the CO2 is coming from water. If they want to propose other CO2 sources, then they should have done so. My barley pop goes flatter faster if it is kept warm after being opened than if it is kept cool. Climate science seems to operate by different laws than the chemical science I studied. Of course the periodic table is a lot bigger than it was way back then.

DP

The next logical conclusion of this is that plants cause ice ages.

Louis Hooffstetter

I second what R Taylor at 10:49 says.
And Go Smokey!

Brian D

Duluth,MN records its warmest March in its long record. Avg temp was 39.2. It finally broke the long held record of 38.8(1878) by a whopping 0.4F. 134yrs ago it was just as warm on the avg. Albeit there were some daily records handily broken that were 50 to 100 years old. But if it can get so damn warm then, why is it such a surprise that it can do it again?! And CO2 is suppose to be a driver? If that’s the best that CO2 can do now with much higher ppms and it can barely squeak out an 1878 record, I think its time to put this AGW thing to rest.

Jeef

Shame there’s no massive NH ice sheets to put a lid on the Atlantic this time.

jimash1

“bolsters the consensus ”
All I have to see .

Interesting how “An Inconvenient Truth” comes up being “A Baldfaced Lie”.
Sure sorry I listened to his shills and paid actual money for that book. Especially since he can now live in fat greasy luxury on the money up stupid people provide.

jayhd

I know I’m an evil denier, but when I see “funded by the National Science Foundation”, “published in the journal, Nature” and “doctoral student at Oregon State University”, my BS meter pegs out and I give absolutely no credence to anything that is written.
Jay Davis

bubbagyro

Peter Miller says:
April 4, 2012 at 11:22 am
So what are we left with?
1. Natural climate cycles warming the oceans and releasing CO2, and
2. Faulty data readings, analysis, or maybe even outright untruths and/or falsification of data.

I think it may be 1. AND 2. Natural climate cycles or catastrophes (meteors, etc.) have to be, logically, the impetus for the melting. I think the analysis of proxies is so fraught with variables as to be dumbfounding the investigators. The data, moreover, as others have said, is inconclusive without error bars of measurements. Not having ± SD is both unscientific and unethical, and I am being charitable.

Wondering Aloud

Another example of changing the facts to fit the scenario of CAGW?

simonw

Have they found where the missing heat goes?

Graeme No.3

Now all they have to explain is why CO2 remains high when the temperature drops, after the interglacial.
By moving the rise in CO2 (on the graph) to before the rise in temperature, they have increased the average time between the temperature dropping and the CO2 level following from an average of 1900 years to nearly 3000 years.
Like the Earth’s orbit, this theory seems to be a bit wobbly…

David, UK

What a steaming pile of crap. The very idea that a minuscule amount of the lesser-important GH gas CO2 “drives” temperature changes via the comparatively massive amounts of the much more important GH gas water vapour is utterly ludicrous. It’s obvious what “drives” this thinking though: political power. History teaches us how persuasive that can be to those willing to be persuaded.

Chris Colose says:
April 4, 2012 at 11:45 am (Edit)
A quick general comment (and reply to Gary’s inquiry)
The paper does not claim that CO2 led everything going on, and you need to distinguish between Antarctic temperatures and global temperatures. A big point of this paper is that considerable spatial structure exists in the deglaciation process.
###############
Thanks chris. It’s astounding how few people actually read and understand the argument.
It’s also sad to see easterbrook repeat the silly “trace” gas argument. Smokey doesnt buy that argument. Anthony doesnt. Lindzen doesnt. Monckton doesnt. Christy doesnt. Spencer doesnt.
Jeff Id doesnt. Singer doesnt. McIntyre doesnt. Scafetta doesnt. and thousands of engineers who build working devices have to account for the powerful behavior of this “trace” gas dont buy that argument. Its funny too, how people forget that GCRs are even “more tracer” than C02.
Oh well. The only people who deny that C02 will warm the planet are those who fail to understand the experimental evidence.

Tilo Reber

Every piece of information that is inconvenient to AGW is either rewritten or adjusted.
Wonder who was driving the SUVs back then.

Jeff L

The comments here are representative of the problems of politicized science. Even if this work was valid, it will be dismissed out of hand as unreliable / unconvincing by many because it supports a certain (pro-AGW) point of view.
Likewise, if there were a valid paper which crushed the AGW theory, it would also be dismissed by many on the other side of the political spectrum simply because it didn’t conform to their dogma.
I can’t comment on the validity of this paper, but it is certainly more intriguing than the average pro-AGW stuff that comes out.

Tilo Reber

Mosher: “Oh well. The only people who deny that C02 will warm the planet are those who fail to understand the experimental evidence.”
Why would you bring that up Mosher? You know damn well that it’s about climate sensitivity, not lab experiments with CO2.