UPDATE: a response to this paper has been posted, see below.
From McGill University , who blows the credibility of their science by putting the word “deniers” in it.
Statistical analysis rules out natural-warming hypothesis with more than 99 percent certainty
An analysis of temperature data since 1500 all but rules out the possibility that global warming in the industrial era is just a natural fluctuation in the earth’s climate, according to a new study by McGill University physics professor Shaun Lovejoy.
The study, published online April 6 in the journal Climate Dynamics, represents a new approach to the question of whether global warming in the industrial era has been caused largely by man-made emissions from the burning of fossil fuels. Rather than using complex computer models to estimate the effects of greenhouse-gas emissions, Lovejoy examines historical data to assess the competing hypothesis: that warming over the past century is due to natural long-term variations in temperature.
“This study will be a blow to any remaining climate-change deniers,” Lovejoy says. “Their two most convincing arguments – that the warming is natural in origin, and that the computer models are wrong – are either directly contradicted by this analysis, or simply do not apply to it.”
Lovejoy’s study applies statistical methodology to determine the probability that global warming since 1880 is due to natural variability. His conclusion: the natural-warming hypothesis may be ruled out “with confidence levels great than 99%, and most likely greater than 99.9%.”
To assess the natural variability before much human interference, the new study uses “multi-proxy climate reconstructions” developed by scientists in recent years to estimate historical temperatures, as well as fluctuation-analysis techniques from nonlinear geophysics. The climate reconstructions take into account a variety of gauges found in nature, such as tree rings, ice cores, and lake sediments. And the fluctuation-analysis techniques make it possible to understand the temperature variations over wide ranges of time scales.
For the industrial era, Lovejoy’s analysis uses carbon-dioxide from the burning of fossil fuels as a proxy for all man-made climate influences – a simplification justified by the tight relationship between global economic activity and the emission of greenhouse gases and particulate pollution, he says. “This allows the new approach to implicitly include the cooling effects of particulate pollution that are still poorly quantified in computer models,” he adds.
While his new study makes no use of the huge computer models commonly used by scientists to estimate the magnitude of future climate change, Lovejoy’s findings effectively complement those of the International Panel on Climate Change (IPCC), he says. His study predicts, with 95% confidence, that a doubling of carbon-dioxide levels in the atmosphere would cause the climate to warm by between 2.5 and 4.2 degrees Celsius. That range is more precise than – but in line with — the IPCC’s prediction that temperatures would rise by 1.5 to 4.5 degrees Celsius if CO2 concentrations double.
“We’ve had a fluctuation in average temperature that’s just huge since 1880 – on the order of about 0.9 degrees Celsius,” Lovejoy says. “This study shows that the odds of that being caused by natural fluctuations are less than one in a hundred and are likely to be less than one in a thousand.
“While the statistical rejection of a hypothesis can’t generally be used to conclude the truth of any specific alternative, in many cases – including this one – the rejection of one greatly enhances the credibility of the other.”
“Scaling fluctuation analysis and statistical hypothesis testing of anthropogenic warming”, S. Lovejoy, Climate Change, published online April 6, 2014. http://link.springer.com/search?query=10.1007%2Fs00382-014-2128-2
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Christopher Monckton has posted a rebuttal to this paper, see here
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I did not find a clear statement of the null hypothesis they were testing. I think it might be “…the temperature record since 1880 is entirely natural.” If they have established this hypothesis is false to the 99% confidence level, then they have achieved agreement with most of Anthony’s readers.
How ridiculous. Smooth 100 years’ temps till it’s as smooth as the CO2 curve … so one must cause the other … oops the latter must cause the former.
Quite a switch from 1708-09:
http://en.wikipedia.org/wiki/Great_Frost_of_1709
I love how confident le petit proffesor is in saying this should “silence any remaining” climate realists, as though he’s exterminating a home, riding it of some pest. Not surprising, though, since I’m sure that’s how he views those who disagree with him.
It also gives the air that he truly thinks there must only be a few of us left. The five or six of them huddled around the dying embers of a campfire, knowing some day, they would be dealt a “blow” from from most-esteemed, tolerant, worldly and unassailable minds of McDonalds University.
This guy isn’t a narcissist at all. Nope. Not one bit.
Another point to examine is their assertion that the natural variation is stochastic. I skimmed their rationale and am not satisfied it addresses all natural variation drivers. Many skeptics, myself included, consider the 20th century to have been in a natural warming trend. So, IMHO, the assumption of stochastic has not had enough time to fully address centuries long natural processes.
If you ignore the MWP and Little Ice Age and use the Mann (98) tree ring proxy and … the CO2 and the temperature time series both look like hockey sticks. QED the correlation is perfect! This is the same tired story for the past 15 years.
Is it any coincidence that as soon as we have a reliable set of global satellite temperature data that the “blade” of the stick falls off? Time to beat the drum about another predicted CAGW calamity.
My concern would be as to which multi-proxy reconstructions were used, and how the author addresses the generally low resolution nature of those reconstructions. I tried reading the paper, but it was too far above my head to make detailed sense of it.
I’ll wait for William Briggs or Steve McIntyre to teach him a few lessons in statistics. He starts by buying the IPPC garbage as to the “science” and assumes what is left (residual) is natural.
Beginning to wish thermometers had never been invented. Perhaps they could be outlawed? I know, I know. Then only outlaws would have thermometers.
anthony –
why didn’t u tell us u were appearing on the MSM constantly?
11 April: Guardian: Dana Nuccitelli: Climate imbalance – disparity in the quality of research by contrarian and mainstream climate scientists
Contrarian papers tend to be rebutted quickly in peer-reviewed literature, but receive disproportionate media attention
A new paper has been published in the journal Cosmopolis entitled Review of the consensus and asymmetric quality of research on human-induced climate change. The paper was authored by John Abraham, myself, and our colleagues John Cook, John Fasullo, Peter Jacobs, and Scott Mandia. Each of the authors has experience in publishing peer-reviewed responses to flawed contrarian papers.
Despite the 97% expert consensus on human-caused global warming supported by peer-reviewed research, expert opinion, the IPCC reports, and National Academies of Science and other scientific organizations from around the world, a large segment of the population remains unconvinced on the issue…
This ‘consensus gap’ is in large part due the media giving disproportionate coverage to climate contrarians. In our paper, we sought to evaluate whether that disproportionate media coverage was justified by examining how well contrarian hypotheses have withstood scientific scrutiny and the test of time. The short answer is, not well…
http://www.theguardian.com/environment/climate-consensus-97-per-cent/2014/apr/11/climate-change-research-quality-imbalance
From the article:
Lovejoy examines historical data to assess the competing hypothesis: that warming over the past century is due to natural long-term variations in temperature.
Well, no kidding! If that isn’t a circular argument, what is?
Lovejoy needs to look at this chart, and explain how current temperatures are different from past temperatures.
If assertions were science, Lovejoy would be another Einstein. But just claiming that he sees the ‘fingerprint of AGW’ in current temperatures is nothing but grant-trolling.
Show us the scientific evidence, Lovejoy. So far, you haven’t.
This is just a rehash of failed science.
The way to determine whether the recent change was human is to determine the normal variation of the climate – something that is familiar to anyone determining the background noise level of any signal analysis.
And then we apply simple statistics to determine if the presumed “signal” is greater than could be expected given the background noise.
What this researcher has done is the equivalent of going to the beach – watching the waves and deciding on a model akin to that of “every sixth wave is the biggest” from which he has determined that his deckchair is 99% safe from any wave … and he has set himself down to sleep … ignoring the known variation i the sea level from the tides.
So, let’s apply some simple statistics.
CO2 was first measured rising from 1958. Before that time most of the variation was natural. From 1910-1940 the temperature rose by 0.48C over 30 years. In the 1970s Hansen was talking of global cooling. From 1970-2000 there was a rise that led to all this concern?
How unusual was this rise from 1970-2000 of 0.48C?
A) It has never happened before
B) Less than once a millennium
C) Around about once every century – and so that type of rise would be expected within a sample period of 150 years.
Based on this answer, what is the probability the recent rise was human?
A) less than 99%
B) less than 90%
C) lower than 50%
Based on this answer above how would you describe someone suggesting a figure of more than 99% that it was human?
Any assertion’s being “directly contradicted by this [bogus] analysis” is evidence for that assertion’s being correct.
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“His study predicts, with 95% confidence, that a doubling of carbon-dioxide levels in the atmosphere would cause the climate to warm … .”
And yet, observed data says:
CO2 UP. WARMING STOPPED.
Dr. Murry Salby’s work more accurately reflects REALITY:
— Net CO2, from both human and natural sources and sinks,
LAGS TEMPERATURE INCREASE by a quarter cycle:
Would LOVE to see ol’ Lovejoy in a head – to – head debate with Salby…
Heh, heh, heh.
JimS says:
April 11, 2014 at 4:02 pm
Gee, if he went back 18,000 to 10,000 years, …I wonder how that happened
Jupiter did it: changed the Earth’s orbit just enough.
We have checked our models and we are 99.9% certain that our models are crap…
Professor Lovejoy, Would you mind sharing how you determined CO2 was THE ONLY DRIVER?
More of the same alarmist crap backed up by crap they are purporting to be science.
Oooohhh Statistical Analysis. I am so waiting for the Audit on that. 🙂
Looks to me that he’s just a Canadian Marcott. I wonder how long it will be before Mann claims him as a long lost child?
Oh noes! We’ve been undone! He’s discovered our achilles heel, and our best-kept secret – just cherry-pick the year 1880, and boom, skepticism is kaput. Well, we,ve had a good run, and some fun times, but now it’s time to pay the piper. Silly us, the jig is up.
Here’s some odds for Lovejoy: the chance that you used, or even attempted to use the scientific method in your “analysis”: none.
The warming 1880 — 1945 could not have been caused by man-made emissions, http://3000quads.files.wordpress.com/2012/12/global_carbon_emission_by_type.png?w=500&h=362&h=362
or if it was, one would expect a vast acceleration in warming since ~1945.
It sounds like just another version of the hockey stick. Sure, if you show flat temperatures for about 500 years and then sharply rising temperatures for 100 years, then you can argue that it is not likely that the increase is due to natural variability. But to establish the flat temperatures, the analysis would have to assert a ridiculous level of accuracy and precision for the 500 years of temperatures derived from proxy data. If you put realistic error bars on it, how in the world could you claim to be sure the temperatures were that flat? They could be going up and down all over the place and still be within the error. Even with our current coverage with thermometers, the government experts claim they have to do significant adjustments to get it right. It seems preposterous to suggest that one could get the necessary accuracy and precision from proxy data. Of course, as most readers of this blog are aware, with the right techniques it is not that hard to manufacture hockey sticks.
Did he use all 200 of the Yamal Trees or just the 12 that showed warming? Was the Upside-down Tiljander proxy included? Seems like the same fruit smoothie…just made in a different blender.
Re: “Canadian Marcott” (Generic Geologist at 5:11pm) — lol.
Bet you’re right!
Mann: “Oh, my dear little long-lost son. I’ve been missing you so much. How’s your mother? What’s that? You wrote a paper?! Oh, joy, let me see it (read, read, read, read). (BIG GRIN).. My, my, you’re just a chip off the ol’ pine block (wink — leer). Now, come on outside and I’ll, uh, teach you a little trick.”
FYI re: Marcott
http://rogerpielkejr.blogspot.com/2013/03/fixing-marcott-mess-in-climate-science.html
This came to mind… . #(:))
Yeah, sure, rIIIggghht, Baghdad Bob Lovejoy.
YOU ARE WEEEENING!!
NOT!
Desperation: not a pretty sight.
(but pretty darn funny, lol)
Shaun Lovejoy’s biggest blunder is his mistaken belief about what the “deniers” actually believe.
He claims they believe that only natural forces have caused the warming. He’s creating a strawman here. I claim he won’t be able to name any serious “deniers” who actually believe that humans haven’t caused at least some of the warming. Exactly why is Lovejoy so dumb about this?
As someone said before, GIGO. But I am sure alarmists will be happy. As they freeze to death.