Guest essay by Eric Worrall
A paper published in Nature claims an estimated 7 – 13c / doubling of CO2 – an estimate so wild it has drawn criticism from NASA GISS chairman Gavin Schmidt.
Evolution of global temperature over the past two million years
Reconstructions of Earth’s past climate strongly influence our understanding of the dynamics and sensitivity of the climate system. Yet global temperature has been reconstructed for only a few isolated windows of time1, 2, and continuous reconstructions across glacial cycles remain elusive. Here I present a spatially weighted proxy reconstruction of global temperature over the past 2 million years estimated from a multi-proxy database of over 20,000 sea surface temperature point reconstructions. Global temperature gradually cooled until roughly 1.2 million years ago and cooling then stalled until the present. The cooling trend probably stalled before the beginning of the mid-Pleistocene transition3, and pre-dated the increase in the maximum size of ice sheets around 0.9 million years ago. Thus, global cooling may have been a pre-condition for, but probably is not the sole causal mechanism of, the shift to quasi-100,000-year glacial cycles at the mid-Pleistocene transition. Over the past 800,000 years, polar amplification (the amplification of temperature change at the poles relative to global temperature change) has been stable over time, and global temperature and atmospheric greenhouse gas concentrations have been closely coupled across glacial cycles. A comparison of the new temperature reconstruction with radiative forcing from greenhouse gases estimates an Earth system sensitivity of 9 degrees Celsius (range 7 to 13 degrees Celsius, 95 per cent credible interval) change in global average surface temperature per doubling of atmospheric carbon dioxide over millennium timescales. This result suggests that stabilization at today’s greenhouse gas levels may already commit Earth to an eventual total warming of 5 degrees Celsius (range 3 to 7 degrees Celsius, 95 per cent credible interval) over the next few millennia as ice sheets, vegetation and atmospheric dust continue to respond to global warming.
Read more: http://www.nature.com/nature/journal/vaop/ncurrent/full/nature19798.html
Gavin Schmidt’s response;
Climate change study accused of erring on rising temperature predictions
…
He (Gavin) said he did not think the conclusion was correct.
“In fact, I’m pretty certain that is an incorrect calculation,” he said.
“The ratio that gave that, which was the very high sensitivity that she calculates, comes from a correlation between temperature and the carbon dioxide and other greenhouse gases from the ice cores, but as we all know, correlation does not equal causation.
“And in this case, the causation is the orbital wobbles of the Earth’s climate that are controlling both the temperature and the carbon dioxide at the same time and so that’s giving you an exaggerated view of how carbon dioxide affects temperature directly.”
However, Dr Schmidt welcomed the temperature history provided by the study, which analysed about 60 different sediment cores.
…
Read more: http://www.abc.net.au/news/2016-09-27/climate-study-under-fire/7881740
It is nice to know there are climate sensitivity estimates which even NASA thinks are implausibly high.
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Crazy claim. Call this science? Demonstrates the fallacy that peer review is the gold standard of quality control.
Paul Homeward has an interesting post on UHI and instrument error/uncertainties. Gradually, the full extent of the manner in which the land based thermometer record has been bastardised by station siting, drop outs, station moves, instrument error and UHI etc will be appreciated and when it is, it will probably be the case that the globe is no warmer today than it was in the late 1930s/early 1940s.
When that is appreciated there will have been no observational warming during this period when man has emitted some 95% of his total manmade CO2 emissions such that Climate Sensitivity on the basis of observational data will be zero or close thereto.
See generally: http://notrickszone.com/2016/09/25/germanys-all-time-record-high-set-in-2015-looks-dubious-likely-due-to-uhi-instrumentation-error/#sthash.b5gRM6A2.k6vMcvRQ.dpbs
It is all part of the gradual Bastardization of Science in general
Pressures to Publish create sensationalization of wording used in articles submitted for publication. This is likely viewed as necessary to gain the desired Media Attention and garner further research grants for the researchers affiliated University. If you don’t bring in Grant $$$, you won’t be a research fellow for more than a few short years, perhaps even months. So pressures to publish are tremendous and sensational wording to grab Media attention is required more than reproducability of research.
See http://www.sciencealert.com/study-warns-that-science-as-we-know-it-is-evolving-into-something-shoddy-and-unreliable
“””””….. Carolyn W. Snyder …..”””””
You’re a dolt.
And that is just my own personal opinion of you. Well I obtained it from proxy reconstructions just like you use (different ones).
After I read your paper, I’ll tell you what I think of your thesis, and also extrapolate from my initial opinion that you’re a dolt.
G
If it is true that with doubling of CO2 is going to raise global warming by 7 – 13 oC then what would be the global average temperature anomaly will be at that time? Is it 18 oC — as the global warming is above half of it [50.1% is also more than half]? If this is the case are we going tom survive any more?
Dr. S. Jeevananda Reddy
What’s the betting it gets added to the IPCC mix so that those papers veering towards a low value get drowned out.
And Dr. James Hansen still thinks five meters of sea level rise by 2100 is possible.
Well, let this be a lesson to all future wannabe alarmists.
Alarmism is welcomed. So, thanks for the “me too” alarmist drivel. But such predictions of massive upheaval will need to be toned down in order to bring them within the range of plausible nonsense.
NASA know that a warming of a degree or so can be pulled like a rabbit from a hat, using only natural variability, adjustments, and a small component of radiative forcing.
But, nobody if going to be able to fool the world into perceiving a warming of 13 degrees.
So, please keep all future predictions within the range of what can be reasonably manufactured.
Thanks.
“in order to bring them within the range of plausible nonsense.”
haha gold!
Well she missed the proxy reconstructions that show that the Temperature has remained between 12 deg. C and 22 deg. C for the last 600 million years.
Does she now expect it could go as high as 30% higher than the total range of earth Temperature for the last 600 million years ??
G
You have to be a Milankovitch denier to derive a climate sensitivity of 7-13C based on paleo data.
“Snyder isn’t convinced that the orbital effects are that important in this case. She says her study provides a single measure of the relationship between historic temperatures and CO2 levels.”
http://www.nature.com/news/longest-historic-temperature-record-stretches-back-2-million-years-1.20673
I suppose she expects the same 13 deg. C increase, for a doubling from 1 ppm of CO2 to 2 ppm of CO2.
So what period of time does her proxy data show has experienced a DOUBLING of CO2 so that she could see (proxyletized), what happened ??
g
What I do not understand is how they acknowledge that this sensitivity predicts that we should have already had 5 degrees of warming, and then completely ignores that. Saying that we should experience that over several millenia is just ridiculous. If we were that far away from equilibrium, we would have monotonic warming, and if was so buffered to slow down warming to observed rates, we wouldn’t have had the temperature swings of the past few centuries, or even the cool period of the 60s.
How does this sort of junk get published anywhere, much less in Nature? Do they not read their own conclusions and think about the implications of their results?
Nature’s published similar sophistry in 1999 by Petit, et al., in the paper that presented the 420,000-year Vostok record. As I tell scientific acquaintances who believe in greater regulation and taxation, “climate change” is a political matter and, thus, unsuitable for casual conversation. Nature is more a political publication than a scientific one.
“Global temperature gradually cooled until roughly 1.2 million years ago..”
As CO2 increased through the last 3 million years?
http://www.ldeo.columbia.edu/~peter/Resources/Seminar/readings/Pearson%20and%20Palmer%202000.pdf
The CO2 levels reported by this paper do not agree with much lower CO2 levels obtained from the Vostok ice core record during the time covered by the latter. Also, this paper calculates CO2 concentration using a constant tropical sea surface temperature of 27 C, and sea surface temperature greatly affects the amount of atmospheric CO2 that is in equilibrium with a given ocean chemistry. Furthermore, this paper does not consider that tropical surface water at any given place and time may have been somewhere else in the world just a year or even only months before and absorbed more CO2 and have gotten a lower pH, and not yet gassed out all of its above-equilibrium CO2.
It still shows a relative increase for the last 3 million years. I would be very surprised if the CO2 in air bubbles in the ice sheets didn’t get partly absorbed by the ice itself, it’s hardly an ideal measure of absolute atmospheric CO2 levels.
Doesn’t Gavin know that orbital wobbles are caused by CO2 levels in the planet’s atmosphere?
tee hee.
The conclusion of a doubling of CO2 per 10 C of temperature change is reasonable from the ice-core data. If you ignore the sequence of changes, i.e. believe that effect precedes cause, you would believe that temperature is the effect and CO2 is the cause. There are many similar examples in nature: The afternoon warmth causes the sun to rise in the morning, and that the cold of winter causes the days to shorten in the fall. Thank goodness politicians are able to purchase such wisdom to guide our societies to ever greater political achievement.
Pity poor Gavin Schmidt, however, who dreads the day someone will ask why CO2 is sensitive to orbital wobbles. Perhaps the wobbles shake the CO2 loose from the clathrates, soils and the other carbonaceous sediments that coat the earth, and it is not the temperature sensitivity of such materials.
Very nice. I think I will be using your “cold of winter” example this Thanksgiving.
Yes R Taylor, and the warming during the day causes the sun to get hotter and hotter.
and the barking dog makes the Postman arrive…
I’m really puzzled. How on earth was this at all accepted by Nature? And why would someone who seems capable of performing a very interesting and thorough proxy analysis commit such an elementary error of confusing correlation with causation? I’m not surprised by Gavin Schmidt’s comments, though, it’s not the first time he objects to obvious over-the-top claims (e.g. he has criticised Wadham’s methane hysteria).
“How on earth was this at all accepted by Nature?”
The sooner that climatologists admit that their discipline is no different than others, we’ll get closer to better data:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1182327/
Or, as they say in the media, “if it bleeds, it leads”.
So much for peer review
And to think that Nature used to be considered a prestigious magazine!
No wonder the EPA is such a mess. From the Washington Post,
” Carolyn Snyder , now a climate policy official at the U.S. Environmental Protection Agency, created a continuous 2 million year temperature record, much longer than a previous 22,000 year record. Snyder’s temperature reconstruction, published Monday in the journal Nature , doesn’t estimate temperature for a single year, but averages 5,000-year time periods going back a couple million years.”
So we have roughly 4800 more years before we can compare a human-influenced 5000-year average with the 5000-year-interval proxy reconstruction.
I’m willing to wait.
Finally we learn the source of the booming voice behind the curtain.
Another bureaucrat out to justify her existence on the public dole.
I’m a bit tired of my tax dollars being wasted on such worthless trash, by public beggars.
G
The warmist Melbourne Age ran this wild prediction of 7 c warming by 1000 years
A first start point for criticising this study is the absurdity of predicting 1000 years out when five sets of IPCC predictions amended every five years have been way out compared with actual observations of global atmospheric temperatures over the past 40 years or so.
I did a back of envelope calculation which I
would appreciate any corrections if needed.
Working on the logarithmic relationship between CO2 and temperature I started with the estimate often cited on this site
That is temperature rises by about 1 c or so for each doubling of atmospheric CO2
Given an estimated 275 ppm in say 1800
and the most recent of 400ppm in 2015 hlobal temperature has increased by about 0.8 c
At current growth of CO2 of 2ppm pa this would see a doubling of the initial 275 ppm to 550 ppm by about the end of this century giving an increase of 1c
To get another 6 degrees c increase by this logic to arrive at the study’s predicted 7
degrees then by this logarithmic doubling rule would require an end CO2 ppm of 35200
If this admittedly simplistic calculation is
broadly right it raises the next question
are there enough carbon-based resources
available to raise CO2 to such astronomical levels?
I suspect not but others may have more
data which could underline the wild nature
of this “prediction” of 7 c warming
Snyder has a huge confidence in feedbacks. Perhaps we have come to a difference of 1,9 W/m2 from preindustrial age. Perhaps it gives a temperature increase of 0,7 degC in non-feedback. (Given about a rise of 1,2 degC for each doubling of CO2). Holding level of CO2 constant for some thousand years should give a temperature rise of 5 degC. A feedback factor of 7. “as ice sheets, vegetation and atmospheric dust continue to respond to global warming.” What a climate!
So this ‘infallible scientist’ who has a resume which does have a Science qualification (BA in Biology & Geology) but is also laden with ‘management consultancy gobbledegook’ has raised the stakes in The Climate Armageddon Poker Game and is now projecting “The Infallibility’ out to a Millenia.
I checked and that is … a period of a thousand years…
And this person graduated from Standford, Oxford and Cambridge. A Professional Student?
What rubbish are these so called Great Universities teaching and does Management Consultancy actually mean…I know how to go about getting all the juicy grants?
1000 years.
That is 3016!!!!! I would like to put in another 995 asterisks but…and it will be cited and referenced from now till the cows come home…in 3016.
I just reread the final sentence and it actually states…over the next few millenia… so the raise in poker stakes is now out to 4016 or even 5016.
What era were The Jetsons set in?
George, Jane, Judy, Elroy, Astro and Rosie the robot maid.
I will leave it to other posters to choose which scenario is the more likely and less fiction of the two.
It reminds one of a child trying desperately to convince Mom that something bad will happen if she doesn’t buy him what he wants, so the child just makes wilder and wilder claims in the hopes of instilling fear. Much like the warmist’s failure to understand that political leanings affecting beliefs on both sides, not just the right, they fail to understand that when the claims become ludicrous, people start to realize this is desperation, not science and not to be believed. It damages any credibility the field may have still have left.
Professor Jeffrey Severinghaus, from the Scripps Institution of Oceanography at the University of San Diego, also found a problem with the study.
“She made a very, very basic logical error,” he said.
“Climate sensitivity is essentially the change in temperature divided by the change in CO2.
“The important part about that is that if you want to infer that from an actual situation in the Earth, you know, what the Earth did in the past, you have to make sure that temperature change is only due to an increase in CO2, whereas the ice ages, we know very well the temperature change was due to a combination of increasing CO2 and changes in the Earth’s orbit around the sun.
“In fact, it’s probably something like two-thirds of the temperature change is due to the orbit and only one-third to the CO2.
“So that’s probably why she got a factor of three larger.”
I love it when trolls try to proclaim supposition as absolute truth.
So, CO2 is still really, really bad, just not quite as bad as this published, peer-reviewed study claims? Thank you for this important contribution…
According to RealClimate’s Jeff Severinghaus, something unknown causes the beginning of warming after periods of maximum glaciation. From my favorite article on RealClimate (with bold added):
The article speculates that Milankovic cycles might be involved in the first 800 years.
http://www.realclimate.org/index.php/archives/2004/12/co2-in-ice-cores/
In a followup article (find it yourself, I don’t want this to go into moderation), Eric Steig hilariously both contradicts and agrees with Severinghaus. And neither of them address the fact (according to the ice cores) that at the end of the inter-glacial periods, when CO2 is at its maximum, cooling then begins and the next glacial period starts. So, problems at both ends of each cycle, for CO2 believers. At the end of glacial maximums, something unknown STARTS the warming. If CO2 is the driver, that shouldn’t happen. Then when CO2 is at its maximum when the warm inter-glacial period ends, COOLING starts, and the next glaciation begins. Again, if CO2 is the driver, that shouldn’t happen, either. These people don’t understand basic logic, they don’t understand cause and effect. Their sophistical attempts to blubber their way out of these problems is a joy to read and should tell you all you need to know about modern “climate science.”
Thank you – that’s a very appropriate comment to this paper; and hilarious as well… 😉
PS
Do we need any more proof that NATURE is no longer a respectable science journal with a meaningful peer review standard?
There are other factors as well, which is why this pack of lies got ECS wrong by a factor of six (at least), not three.
Rather than nine degrees C per doubling or three, the central value is actually more like 1.5 degrees C, if that high.
“but as we all know, correlation does not equal causation.”
Too bad they can’t follow this rule when it comes to 20th century temperature readings.
Apparently, what Snyder is talking about is something called ‘Earth System Sensitivity’ which, as far as I can tell, is like Equilibrium Climate Sensitivity but with even more long term feedbacks added in. So I guess we’re talking many thousands of years. So why you might ask does Snyder relate it to current emissions and start talking about an alarming 5-7C already in the pipeline? ECS and TCR are far more relevant measures.
What Snyder is talking is bovine coprology.
Well, yes, Pleistocene auroch dumps were a major climate feedback back then.
JJ, no. The ice cores show delta CO2 lags delta T by about 800 years. See essay Cause and Effect for details in ebook Blowing Smoke. Simple logical consequence of thermohaline circularion and Henry’s Law. She has 2 million years of causality reversed. Should never have passed peer review, let alone in Nature.
Only since ~1900 has there been any delta anthropogenic CO2 that might causally drive future AGW, and it is only that sensitivity that matters for CAGW. Observationally by several methods ~1.65 (range maybe 1.5-1.8). CMIP5 median is 3.2, mean 3.4. We know those cannot be right because the models also error in other significant ways (e.g. Tropical troposphere hotspot).
ristvan,
“The ice cores show delta CO2 lags delta T by about 800 years.”
You need to be careful here. The Vostok data shows about an 800 year lag, but the DomeC data, which seems to be better temporally aligned with orbital data, shows a lag of only between 200 and 300 years. The lag is also somewhat asymmetric depending on whether temperature is increasing or decreasing. The most logical explanation for this is the response of the planets biomass to changes in the available land to support it. As less land is covered by ice, more land can become alpine forests and it takes on the order of centuries for the existing biomass to accumulate enough atmospheric carbon to grow a forest and sustainably continue its growth going forward.
We would have the same northern hemisphere clockwise ocean currents even if the oceans were pure fresh water .
It would require stoppage of earth’s rotation to stop it, and reversal of that rotation to make the rotation anti- clockwise.
With ocean water rushing Westward across the oceans, due to water not having infinite viscosity, it has to pile up on Eastern coastlines, before it stops. And when it stops its Westward rush, it must collapse and the only place to go in the northern hemisphere is north along the coast.
Opposite that in the southern hemisphere.
Nothing thermo-haline about it.
G
“Apparently, what Snyder is talking about is something called ‘Earth System Sensitivity’ which, as far as I can tell, is like Equilibrium Climate Sensitivity but with even more long term feedbacks added in.”
Exactly. People should listen to these distinctions. It is not the same thing as ECS, which is in turn different from TCS..
And Gavin is right that it is problematic. You can only get it by observing over millions of years, but then it is almost impossible to work out causality.
Nick writes “Exactly. People should listen to these distinctions. It is not the same thing as ECS, which is in turn different from TCS..”
Ridiculous Nick. ECS is the sensitivity at equilibrium. If there are more feedbacks that resulted from the initial CO2/warming then we’re not at equilibrium yet. Did you feel dirty when you wrote that?
“then we’re not at equilibrium yet”
No, equilibrium is always relative to some timescale of interest. Otherwise you could say we’re never at equilibrium, since the Sun is going through its evolution which will eventually engulf us, etc. Chemical equilibrium is defined relative to the reaction kinetics. And climate equilibrium is considered relative to various transport processes – basically those that are treated by GCM’s, of which the slowest is the diffusion of heat in the oceans. It doesn’t include processes like rock weathering, movement of continents.
ESS (which does not include the word equilibrium) does try to cover these latter processes. There are problems, because they can’t be observed to change on human timescales, and also there is no longer a clear partition between what is in or out (I doubt it includes solar evolution). For that reason you don’t see it commonly mentioned. My point here is simply that it is different. You can try to infer it from geological-scale observations, but then there is the problem of causality, which is what Gavin and others are disputing.
Nor does it include being on a body that rotates once in about 24 hours.
Run a blow torch around in a circle, going over the same path over and over again.
Just when does the table top reach equilibrium ?
g
I wonder what number she would have gotten if she looked at the end of interglacial periods? It often takes about 5000 years for the CO2 to return to the low glacial levels while temperatures fall much more quickly. So, in this case the lower CO2 in the future reduces temperatures in the past???
I suspect this may be why she throws out the claim it may take a few millennia although even that does not make sense at glacial onset. Does she say anywhere in the paper where the heat is hiding across these millennia and the mechanism for that behavior?
I wouldn’t consider something that happens once in 5,000 years, something that happens “often”.
That is maybe 2% of a happening in one persons lifetime. Not exactly something that we eventually get bored with.
g
The climate is far too complicated for most to understand, so the warmunists have found they can consolidate and blame everything, even orbital wobbles, on a singular God of C02. It makes messaging easier for the masses to understand and the peer reviewers don’t even dare to object anymore lest they be accused of heresy and be excommunicated or worse. It’s really exciting to be witnessing the birth of a new religion.
A position I’ve run into among some otherwise very smart people is “I don’t understand climate, so I’ll defer to the Experts.” At which point it becomes a debate of Authority trying to get them to see reason. Present evidence and they blindly interpret it as the “Experts” say it should be interpreted. Postulate that the “Experts” themselves don’t understand it and their retort is “prove it”.
Carolyn W Snyder. Bio in her own words.
“I am the Director of U.S. EPA’s Climate Protection Partnerships Division. The Division uses the power of partnerships to remove market barriers for energy efficiency and renewable energy and reduce greenhouse gas emissions, resulting in economic and environmental benefits. The Division’s programs include the EPA’s flagship partnership program, ENERGY STAR, which offers energy efficiency solutions across the residential, commercial, and industrial sectors. Other programs include the Green Power Partnership, the Combined Heat and Power Partnership, the Center for Corporate Climate Leadership, and the State and Local Climate Energy Program”.
Read the rest here:
http://www.carolynsnyder.com/
This paper, with all its flaws and the many criticisms received, will be enthroned as a seminal article in 6 months, and used in many ways in future debates and analysis, not the least of which will be to make many climate sensitivity “measurements” of 3 to 5 degrees C (for a doubling of CO2) — despite their less obvious flaws, but equally non-sensical logic or data torturing — seem reasonable and certain.
I expect in a few months all criticism of this paper will cease and be forgotten, if not “purged” from the record. Its predictions will held out as a “possible, but not as likely” and frequently mentioned.
But you do realise that this can now be used to pull the average back up to the 4-5 degree rise that the alarmists are still trying to scare people with.
The recent slew of papers showing sensitivity around 1-2 has been seriously undermining the scary scenarios and the alarmists needed something new to add to the reviews before the “mean” was pulled too far down in the next IPCC PR release. That is the point of this paper. Having failed to get the non-scary estimates disqualified (now that there are editors prepared to publish them, they can’t use the redefinition of peer review tactic), more publications in the scary end are needed.
Heh, i thought that “the science was settled”. And here it is another paper with a different climate sensitivity.
I guess this refutes Lewandowsky and Cook´s last paper when they say that the climate scientific community provides a coherent world view. Nope, It is not coherent neither precise. 7 to 13 degrees Celsius is highly imprecise.