NOTE: As is typical these days, and in keeping with co-author Phil Jones tradition of not giving up anything, the publicly funded scientific paper is not included with the news, and is hidden behind a paywall. All we can get is the press release and abstract and this silly picture of the researcher grinning like a banshee. Speculate away with impunity. I wonder why he has the ozone hole in Antarctica next to the HadCRUT temperature series?
Caption: David W.J. Thompson, professor of atmospheric science at Colorado State University, is the lead author of a Nature paper that shows sudden ocean cooling contributed to a global warming hiatus in the middle 20th century in the Northern Hemisphere. Credit: Colorado State University
FORT COLLINS – The hiatus of global warming in the Northern Hemisphere during the mid-20th century may have been due to an abrupt cooling event centered over the North Atlantic around 1970, rather than the cooling effects of tropospheric pollution, according to a new paper appearing today in Nature.
David W. J. Thompson, an atmospheric science professor at Colorado State University, is the lead author on the paper. Other authors are John M. Wallace at the University of Washington, and John J. Kennedy at the Met Office and Phil D. Jones of the University of East Anglia, both in the United Kingdom.
The international team of scientists discovered an unexpectedly abrupt cooling event that occurred between roughly 1968 and 1972 in Northern Hemisphere ocean temperatures. The research indicates that the cooling played a key role in the different rates of warming seen in the Northern and Southern Hemispheres in the middle 20th century.
“We knew that the Northern Hemisphere oceans cooled during the mid-20th century, but the sudden nature of that cooling surprised us,” Thompson said.
While the temperature drop was evident in data from all Northern Hemisphere oceans, it was most pronounced in the northern North Atlantic, a region of the world ocean thought to be climatically dynamic.
“Accounting for the effects of some forms of natural variability – such as El Nino and volcanic eruptions – helped us to identify the suddenness of the event,” Jones said.
The different rates of warming in the Northern and Southern Hemispheres in the middle 20th century are frequently attributed to the larger buildup of tropospheric aerosol pollution in the rapidly industrializing Northern Hemisphere. Aerosol pollution contributes to cooling of the Earth’s surface and thus can attenuate the warming due to increasing greenhouse gases.
But the new paper offers an alternative interpretation of the difference in mid-century temperature trends.
“The suddenness of the drop in Northern Hemisphere ocean temperatures relative to the Southern Hemisphere is difficult to reconcile with the relatively slow buildup of tropospheric aerosols,” Thompson said.
“We don’t know why the Northern Hemisphere ocean areas cooled so rapidly around 1970. But the cooling appears to be largest in a climatically important region of the ocean,” Wallace said.
Global temperatures 1850-2010 [Nature News]
An abrupt drop in Northern Hemisphere sea surface temperature around 1970
David W. J. Thompson1, John M. Wallace2, John J. Kennedy3 & Phil D. Jones4
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523, USA
- Department of Atmospheric Sciences, University of Washington, Seattle, Washington 98195-1640, USA
- Met Office Hadley Centre, Met Office, Exeter EX1 3PB, UK
- Climatic Research Unit, University of East Anglia, Norwich NR4 7TJ, UK
Correspondence to: David W. J. Thompson1 Email: davet@atmos.colostate.edu
Abstract
The twentieth-century trend in global-mean surface temperature was not monotonic: temperatures rose from the start of the century to the 1940s, fell slightly during the middle part of the century, and rose rapidly from the mid-1970s onwards1. The warming–cooling–warming pattern of twentieth-century temperatures is typically interpreted as the superposition of long-term warming due to increasing greenhouse gases and either cooling due to a mid-twentieth century increase of sulphate aerosols in the troposphere2, 3, 4, or changes in the climate of the world’s oceans that evolve over decades (oscillatory multidecadal variability)2, 5. Loadings of sulphate aerosol in the troposphere are thought to have had a particularly important role in the differences in temperature trends between the Northern and Southern hemispheres during the decades following the Second World War2, 3, 4. Here we show that the hemispheric differences in temperature trends in the middle of the twentieth century stem largely from a rapid drop in Northern Hemisphere sea surface temperatures of about 0.3 °C between about 1968 and 1972. The timescale of the drop is shorter than that associated with either tropospheric aerosol loadings or previous characterizations of oscillatory multidecadal variability. The drop is evident in all available historical sea surface temperature data sets, is not traceable to changes in the attendant metadata, and is not linked to any known biases in surface temperature measurements. The drop is not concentrated in any discrete region of the Northern Hemisphere oceans, but its amplitude is largest over the northern North Atlantic.
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hmmm, maybe this graph from ICECAP will help them:
And this too:
The historical variability of the Arctic Oscillation. 1969-1970 was darned cold.
Also see this image from the Climate Prediction Center:
ALSO: Quote from Phil Jones: Reuters
Jones, at the centre of a furore over e-mails hacked from the University of East Anglia in late 2009, was reinstated this year after reviews cleared him of suspicions of exaggerating evidence in favour of global warming.
Thursday’s paper is the first he has since published in Nature. “Maybe it will get them thinking,” he said, asked how climate sceptics would react to his involvement in a paper highlighting a cause of cooling, rather than warming.
——————-
I wonder how good that Southern Hemisphere SST data is back in the 1960s, which is used here to demonstrate “robustness”. From Physicsworld.com
I think it would be more accurate to characterize the grin as (the polite term) “coprophagous.”
Interesting. I like how CO2 soaring was included int he figure above the cooling, then when it got warming, there’s CO2 increasing.
But I thought that cooling was due to particulates and aerosols now regulated by government?
I think it’s amusing that warmists are just coming around to the idea that maybe the oceans have a bigger impact on planetary temperature than CO2. Something that we chemists have known for a long time. If you chart El Nino / La Nina versus planetary temperature, you’ll see a nice correlation.
I have a new one for Kate’s list: We are not to call it Global Warming anymore. Instead, let’s use “Cooling Hiatus” — John M Reynolds
Ron,
As to other benefits of carbon fuels reduction, I was thinking of energy independence, not sending billions to countries that support terrorism, reduced pollution (the traditional kind not greenhouse gases), no more Deepwater Horizons, etc.
Are you saying that the authors of the NAS report didn’t look closely at the science?
As for AGU, on the front page of their website today is a link to an article defending Phil Jones. Then you go to their Earth and Space Science News Archive and we find articles about scientists sending letters to Congress in support of the IPCC, about CRU researchers being cleared of distorting climate data, etc. Doesn’t seem like they are about to switch to the skeptic view of AGW anytime soon.
With respect to your claims about careers being ruined, etc., at some point you guys are going to have to stop giving excuses for the failure of the skeptical scientists’ ideas to persuade science at large. As you note, it’s more acceptable than ever for scientists to be skeptical of the mainstream view. So it’s time to put up or shut up. Sure, the “warmists” are well funded. But there are enough universities and think tanks to support alternative science. It’s time to write something that isn’t debunked AND actually goes to the heart of AGW, such that it can persuade the majority of scientists that AGW is not real and is not a serious threat. So far the skeptics have drawn blanks on that. At some point, when you fail to persuade, you need to look at yourself and stop making excuses.
Stephen Wilde says:
September 23, 2010 at 4:07 am
There are many scientists who still think human CO2 emissions can affect global temperature but we don’t take much notice of them these days. The science is moving on and the major concern now is working out why both the 70s cooling and 90s warming fears both turned out to be wrong.
The fears turned out to be unfounded, not because anything unusual was going on, but because we did not realize that the climate varies so much. The really scary part is the fact that temperatures can vary that much in a lifetime. Before the advent of temperature measurements, mankind was only aware of the consequences of back-to-back cooling or warming trends. The consequences being failed crops, pestilence, mega-droughts, little ice ages, etc.
Now that we know that it is normal for temperatures to go through 30 year trends and promptly reverse course, the next trick is to try and understand why this reversal is normal, why there are periods in our past where reversal didn’t happen, and when such things will happen in the future.
It just so happens that climate change is wide open for abuse, no matter which way it is currently headed, due to massive lack of long-term knowledge.
David,
As you say, “Their failure was that they have not stopped us.” That’s the point. Nothing is stopping scientists that believe AGW is false or not serious from getting their views out today. Pielke, MacIntyre, Christy, and others. They’ve all made presentations, gotten their ideas out. Their views have not persuaded science at large that AGW is not a serious threat. Bottom line, they have failed to persuade. Their ideas were not strong enough, did not go to the heart of AGW or were wrong in the eyes of science at large. So we have the NAS reports from this year, with the headline on their website: “Strong Evidence on Climate Change Underscores Need For Actions to Reduce Emissions and Begin Adapting to Impacts.”
http://americasclimatechoices.org/?utm_medium=etmail&utm_source=National%20Academies%20Press&utm_campaign=NAP+mail+cb+05.19.10&utm_content=Customer&utm_term
Ron,
I’m just a layman (mechanical engineer), but I think there’s already been plenty to show that this science is not settled. In my view, the concetnration on CO2 drives the focus away from true energy independence and is a political weapon aimed at so called non-sustainable energy systems.
Surveying articles and data from all sources:
1. There is not agreement on the impact of CO2; I have seen multiple articles on feedback and degree of the effect.
2. Forecasts by AGW proponents have not come true except in isolated cases. There has been no significant increase in hurricanses/tropical storms, sea levels haven’t risen significantly, and ice volumes have not decreased at the rates predicted.
3. Data sources are corrupt at least to some degree. This could fill a book, so it’s easier just to search the archives on WUWT.
4. AGW seems to oversimplify the impacts of all sources of thermal impact on the earth. Even to me, there should be effects by oscillation of the earth’s axis, solar radiation, cloud cover, moisture, etc.
I’ve already been led by the nose on the ozone issue where I trusted the science; I’m not going there again.
I think its pretty well known now that the AMO affects global SSTs… Not only NH ones…
Cliff says:
September 23, 2010 at 7:37 am
“It’s time to write something that isn’t debunked AND actually goes to the heart of AGW, such that it can persuade the majority of scientists that AGW is not real and is not a serious threat. So far the skeptics have drawn blanks on that. At some point, when you fail to persuade, you need to look at yourself and stop making excuses.”
Cliff, you are so far off the mark it’s untrue!
Here is a list of 800 peer-reviewed papers supporting scepticism of CAGW.
http://www.populartechnology.net/2009/10/peer-reviewed-papers-supporting.html
These papers actually got through a highly ‘consensus biased’ peer review process, but only a tiny proportion got widespread publicity in the MSM.
Read the Climategate emails to see how climate scientists colluded with the MSM to subvert the peer review process and to suppress non-consensus media reporting.
Follow the money to see who will benefit from a carbon tax and check which bits of the MSM they own.
Read the list of IPCCgate revelations to see how science is being used to justify political ends, which include reducing world population and the redistribution of wealth.
Luckily the tide has turned against CAGW as our climate oscillates back into cold-century mode. It is now much too late for world carbon control legislation to be agreed.
Tenue,
I sincerely hope you are right that the climate will go into some kind of cold mode and prove the warmists wrong (or at least buy us a lot of time). One good thing about this debate is that if the warmists are right, and I currently think they are, we are going to be in deep shit by mid-century and that will be clear to anyone with half a brain. So the debate is kind of going to resolve itself in 20 or so years.
I find those 800 papers really encouraging. It turns out that climate skeptics have NOT been prevented from getting their views out. Blacklists, speculation about young scientists’ careers getting ruined – all this has not stopped anything. This only proves my point. Skeptics’ views and ideas have gotten out. They just were unable to persuade the majority of scientists that AGW is not a serious threat. Time for 800 better papers that have more persuasive force and go to the hear to heart of AGW (not monkey with the edges or pieces of it).
Say Anthony,
I’m not a weather or climate geek like you; so maybe this is a dumb question; but I’ve been known to ask dumb questions.
So some of us have believed some data and statements by some fairly well known apparently AGW skeptical climae scientists to the effect that the period of recent (izzat neo ?) global warming probably stopped about 15 years ago; about 1995; well save for that pesky 1998 El Nino spike.
So let’s go out on a limb, and “assume” that that is a correct conclusion.
So if the planet earth stopped warming about 15 years ago; and seems to have cooled since, would it be fair to say that SOMETHING on earth might have actually gotten colder during that time frame. I mean, how can the whole planet cool if everything warms up; so something must have got colder.
Now the atmosphere goes everywhere; at least everywhere on the outside of the planet; but it is fairly low density; so if it got colder, it wouldn’t really matter too much in the scheme of things, since it has such a low relative thermal capacity.
So it would seem to be necessary to have something else besides the atmosphere get colder, in order for the whole darm place to register an overall cooling.
Well besides the atmosphere around the planet; there’s not a whole lot left on planet earth to be a suitable candidate fro a significant amount of cooling that would show up overall.
I mean we have the land; and we have the oceans; and there’s not a hell of a lot more of other things that might get colder besides the atmosphere.
So if it isn’t the land that cooled; and it isn’t the oceans that cooled; what the blazes else could it be.
Apparently theres about a 70:30 split between the oceans and the land; so a lot more oceans than land; so if you had to pick one to be the main thing that cooled, does it make any sense to you that it might be the oceans that cooled ?
Yeah I know; I said it was a dumb question; and I’m rather embarrased to have to ask; but does that make any sense to you; if the whole planet on average gets cooler; it is quite likely that the oceans would show some cooling.
Not a big deal Anthony; but if you have any thoughts on it; and have some time ?
Djozar, the ozone hole is healed and will be back to normal by 2050, all thanx to the montreal accord.
http://www.huffingtonpost.com/2010/09/16/ozone-hole-2010-internati_n_719652.html
http://www.examiner.com/environmental-policy-in-national/upper-level-ozone-hole-healed-world-environmental-policy-protection-success
DeNihilist;
Considering that we don’t have information on the extent of the ozone layer before 1970, how can it be claimed that it’s recovering? Not being sarcastic, just wondering.
Looking at their Nature News graph, I can see a sudden cooling at 1900 and another one at about 1945; but I don’t see a darn thing happening at 1970 on that graph; well outside of the random noise of course.
So what the blazes are they talking about; and why is that chap grinning like that? Izzat some sort of trick picture that we aren’t supposed to be able to figure out.
And I love that “measurement artefact” which I will translate for free into American, as “measurement artifact”. Well it could be a typo; which we don’t do, rather than British speeling.
But that event is 1970 sure was fast, and gone before you could tell it was there.
Is it standard practice in high class peer reviewable Climate Science to publish data containing known measurement artifacts.
When do the authors plan to release the revised paper containing no measurement artefacts ?
These guys are big on symptoms and small on fundamentals. Gawping at a mass of chaotic data and proclaiming parts of it significant is medieval; it’s dumb numerology.
This isn’t science, and Climatologists they carry their ‘ology’ under false pretences. At best they’re worth an ‘ography’.
Cliff says:
September 23, 2010 at 8:01 am
So Cliff, if the cooling of the 70’s wasn’t aerosols, what was it? The AGW apologists blame it on aerosols to erase the difficulty of cooling temps/rising [CO2]. Give us you intrepretation.
And by the way folks, give my alma mater a break here. ;~P
Speculate away with impunity. I wonder why he has the ozone hole in Antarctica next to the HadCRUT temperature series?
Because they are saving the world? Its a secret message to green activist sleepers who have been primed to wake up when they see these two iconic images of the problems facing mankind, they used to use the hockey stick as a stimulus but this has lost some of its power recently. Green activists looking at this picture will swoon with pride and then when they recover they will be all fired up to wage war and mount another attack on “the deniers”
Funny how they all refer to the HadCRUT global temperature curve and try their utmost to find an explanation to what the curve shows. It is like discussing holes in a flat Earth…
And, could not the gradual reversal of that sudden cooling account for the subsequent resumption of the warming?
Tim,
Actually I think the authors here are reporting it was not purely aerosols. So they are reporting something here that calls into doubt their prior explanation. Wow, that doesn’t sound like someone afraid of the truth or only interested in a one-side presentation of stuff that supports their theory.
As to my theory? I don’t have one. The authors themselves don’t have a theory. It seems the PDO is being floated as an explanation here but the authors seem to say oscillations don’t fully explain it either. Seems like something for further study. But in any event the cooling of the 70s halted and things returned to warming. So maybe we can hope an unexplained cooling phenomena will come back and buy us some more time. That would be great! But I’m not exactly counting on it when we don’t know the cause apparently.
Ben:
At September 23, 2010 at 12:24 am you say:
“Correct me if I’m wrong, but if the cooling wasn’t down to aerosols, then doesn’t that in itself invalidate most or all of the IPCC climate models…”
You are not “wrong”. Indeed, you are very, very right and this invalidation of the models has been known for a long time.
A decade ago I published a peer-reviewed paper that showed the UK’s Hadley Centre general circulation model (GCM) could not model climate and only obtained agreement between past average global temperature and the model’s indications of average global temperature by forcing the agreement with an input of assumed aerosol cooling. And my paper demonstrated that the assumption of aerosol effects being responsible for the model’s failure was incorrect.
(ref. Courtney RS An assessment of validation experiments conducted on computer models of global climate using the general circulation model of the UK’s Hadley Centre Energy & Environment, Volume 10, Number 5, pp. 491-502, September 1999).
More recently, in 2007, Kiehle published a paper that assessed 9 GCMs and two energy balance models.
(ref. Kiehl JT,Twentieth century climate model response and climate sensitivity. GEOPHYSICAL RESEARCH LETTERS, VOL. 34, L22710, doi:10.1029/2007GL031383, 2007)
He found the same as my paper except that each model used a different aerosol ‘fix’ from every other model.
Kiehl says in his paper:
One curious aspect of this result is that it is also well known [Houghton et al., 2001] that the same models that agree in simulating the anomaly in surface air temperature differ significantly in their predicted climate sensitivity. The cited range in climate sensitivity from a wide collection of models is usually 1.5 to 4.5 deg C for a doubling of CO2, where most global climate models used for climate change studies vary by at least a factor of two in equilibrium sensitivity.
The question is: if climate models differ by a factor of 2 to 3 in their climate sensitivity, how can they all simulate the global temperature record with a reasonable degree of accuracy. Kerr [2007] and S. E. Schwartz et al. (Quantifying climate changetoo rosy a picture?, available at http://www.nature.com/reports/climatechange, 2007) recently pointed out the importance of understanding the answer to this question. Indeed, Kerr [2007] referred to the present work and the current paper provides the widely circulated analysis referred to by Kerr [2007]. This report investigates the most probable explanation for such an agreement. It uses published results from a wide variety of model simulations to understand this apparent paradox between model climate responses for the 20th century, but diverse climate model sensitivity. ”
And his paper says:
“These results explain to a large degree why models with such diverse climate sensitivities can all simulate the global anomaly in surface temperature. The magnitude of applied anthropogenic total forcing compensates for the model sensitivity.”
And the “magnitude of applied anthropogenic total forcing” is fixed in each model by the input value of aerosol forcing.
I cannot post Kiehle’s Figure 2 here but it is for 7 GCMs and 2 energy balance models. Its title is this:
“Figure 2. Total anthropogenic forcing (Wm2) versus aerosol forcing (Wm2) from nine fully coupled climate models and two energy balance models used to simulate the 20th century.”
So, each model uses a different aerosol ‘fiddle factor’ to get it to emulate past global temperatures of the Earth. But there is only one Earth and, therefore, at most only one of the models can be right and they are probably all wrong.
The underlying problem is that the modelers assume that additional energy content in the atmosphere will result in an increase of temperature, but that assumption is very, very unlikely to be true.
Radiation physics tells us that additional greenhouse gases will increase the energy content of the atmosphere. But energy content is not necessarily sensible heat.
An adequate climate physics (n.b. not radiation physics) would tell us how that increased energy content will be distributed among all the climate modes of the Earth. Additional atmospheric greenhouse gases may heat the atmosphere, may have an undetectable effect on heat content, or may even cause the atmosphere to cool.
The latter could happen, for example, if the extra energy went into a more vigorous hydrological cycle with resulting increase to low cloudiness. Low clouds reflect incoming solar energy (as every sunbather has noticed when a cloud passed in front of the Sun) and have a negative feedback on surface temperature.
Alternatively, there could be an oscillation in cloudiness (in a feedback cycle) between atmospheric energy and hydrology: as the energy content cycles up and down with cloudiness, then the cloudiness cycles up and down with energy with their cycles not quite 180 degrees out of phase (this is analogous to the observed phase relationship of insolation and atmospheric temperature). The net result of such an oscillation process could be no detectable change in sensible heat, but a marginally observable change in cloud dynamics.
However, nobody understands cloud dynamics so the reality of climate response to increased GHGs cannot be known.
Richard
“The net result of such an oscillation process could be no detectable change in sensible heat, but a marginally observable change in cloud dynamics.”
That has been my published contention for some time now with the latitudinal positioning of the air circulation systems standing as a proxy for the change in cloud dynamics.
Back in the 70’s I was privy a study of CFC’s by the University of Washington and
Battlle NW labs. They had a instrumented Aircraft flying at all levels of the atmosphere that Airbreathers could reach. One such research paper could NOT find a correlation with the Ozone breakdown or depletion. One of the scientitsts speculated that CFC’s heavier than air, anyway, would just simply circulate until they broke down.
That wasn’t what they wanted to hear. So it didn’t get the peer review or the funding that was needed-Sound familiar?….
I’d like to know what happened to that bit of research-can’t find it on the web.
hmm..
Cliff says:
September 23, 2010 at 10:35 am
“So maybe we can hope an unexplained cooling phenomena will come back and buy us some more time. That would be great! But I’m not exactly counting on it when we don’t know the cause apparently.
No need for hope, Cliff, the cooling phenomenon is already back and is easy to explain.
Our climate is driven by deterministic chaos and, as a result, is driven by many quasi-cyclical events. This mean the 21st century will be a cool one as it is on the downturn of a 200y temperature oscillation, like this:-
1410-1500 cold – Low Solar Activity(LSA?)-(Sporer minimum)
1510-1600 warm – High Solar Activity(HSA?)
1610-1700 cold – (LSA) (Maunder minimum)
1710-1800 warm – (HSA)
1810-1900 cold – (LSA) (Dalton minimum)
1910-2000 warm – (HSA)
2010-2100 (cold???) – (LSA???)
Historically, mankind and the rest of the biosphere have always thrives during warm periods. The only scary thing is just how cold is the current period going to get?