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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Glad I found these posts, I was hoping I wasn’t the only one who thought his claims were stupid.
There seem to a rash of these. Similar one I read was ‘14000 dead in US because of Fukushima sort of things.
The prniciple; is simple sleight of mind. Its a complex straw man exercise:
1/. Decide what you want to ‘prove’
2/. Find some unrelated issues, and propose them as the only alternatives.
3/. Show that they cant possibly explain the thing you want to ‘prove’
4/. Thereby deduce that the only issue left standing PROVES the thing you want to prove.
” There were seven suspects in this case m’lud: Mr Carbon D’oxide, Mr Industrial Emission, Mr Solar Variability , Ms Random variability, Mrs Volcano eruption, Young master Chlorinated Fluoro-Carbon and the pet cat Random Supernova: All had alibis, except Mr Carbon d’Oxide, so he is guilty as hell.”
“Did you look elsewhere for another suspect”
“No M’lud, we only interviewed the others because Mr D’Oxide claimed he was innocent’
“And how did you pick the other potential suspects”
“From a tattered list of the ‘usual suspects’ we keep for cases like this m’lud”.
“So, let’s get this straight, from all the possible people in the world, at least 70 million of whom probably don’t have alibis, you decided this one man was guilty Why was that?”
“Because everybody knows he is M’lud”.
Validity of such an argument when there ISN’T any “global warming”? None.
“It was the CFCs, stupid!”
“””””…..Janice Moore says:
April 12, 2014 at 2:52 pm
Mr. Smith,
Re: yours of 2:41pm today, there are several “assistants” of Rutherford mentioned in this biographical article: http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1908/rutherford-bio.html
Perhaps your “lab technician” is named……”””””
Janice, I can’t say I recognize his name in that bio; I should look it up, because his contribution was not minor. And “lab technician” ; is just a label and was in no way, a downgrading of his careful work
The prevailing view of the “atom”, was like a plum pudding with electrons embedded in the surface like raisins (and thruppenny bits inside the pud). So all the nuclear material was supposed to be the pudding, consisting of protons plus some electrons to explain the atomic weight being larger than the atomic number.
Classical electro-magnetic theory, would have a charged particle like an alpha (He 2-) getting deflected while charging through the pudding, but only over a small angle because of the size of the atom. So Rutherford expected to find alphas deflected only in a small angle spread.
Instead his assistant found a wide angle spread, including alphas coming completely backwards.
Rutherford deduced that this was only possible (under classical Maxwell electromagnetism), if the charge of the atom core (pudding) was in fact contained in a very tiny central region, (nucleus) that occupied almost no space in the atom, so the alpha could go right through and pass very close to that nucleus, and thus the 1/r^2 force would be much higher giving a much greater deflection angle.
It was in 1938 (I think) that Chadwick discovered the neutron, and it was realized that the difference between atomic weight, and atomic number, was in the number of neutrons in the nucleus, and not a surfeit of protons plus the difference in electrons. Well a neutron behaves not too unlike an electron squished onto a proton, cancelling the charge, and increasing the mass.
By anybody’s measure, Rutherford’s discovery of the nuclear atom, was a very big deal for physics, as big as Bohr’s atomic structure explanation of the hydrogen spectral lines was.
That was a golden age of physics, and science in general.
When I look at history I see a roughly 1,000 year cycle.
Roman warming period -> Medieval warming period -> “Post-WW2” warming period.
Apart from that, his methodology with using data going back to 1500 is utterly flawed. We don’t have enough measured data from those years. Large parts of the world didn’t have thermometers or temperature records.
The “study” is already wrong simply because of that.
First, Lovejoy has reversed the null hypothesis:
“Lovejoy examines historical data to assess the competing hypothesis: that warming over the past century is due to natural long-term variations in temperature.”
That’s not a “competing” hypothesis. It’s the NULL HYPOTHESIS. You don’t get to just take the null hypothesis and put it up to the same scrutiny as what you’re trying to prove. Alarmists have been trying to convince everyone for years that the null hypothesis should be THEIR assumption, and it hasn’t flown, so this guy just ignores the fact that the scientific method doesn’t allow him to do it and does it anyway.
Second, he says “the probability that global warming since 1880 is due to natural variability … may be ruled out ‘with confidence levels great than 99% …’. But everyone, even the alarmists, agree that any warming prior to 1950 WAS natural. So he’s “proven” the alarmists wrong too. (Actually he’s only proven that there’s something wrong with his own methods)
Third, as far as I can tell, this guy’s analysis appears to be nothing more than an Ordinary Least Squares regression model. As such, it is highly dependent on which explanatory variables he CHOSE to include in the regression. The only explanatory variable explicitly mentioned in the story is carbon dioxide levels. I wonder if he included any “natural variation” explanatory variables, like solar activity or cloud cover. If not, then he didn’t even get the reversal of the null hypothesis right, because if you’re “trying to prove” that natural variation caused the warming, then you should have some explanatory variables that represent natural variation.
Fourth:
“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.”
Of course the fact that “computer models are wrong” doesn’t apply to this study, because this study doesn’t use computer models. But how do we know that the computer models wrong? Because 1) they fail to accurately simulate a plethora of natural factors, and 2) they have failed to predict anything remotely accurately so far. As far as I can tell, Lovejoy’s analysis didn’t even include natural factors, and even if it did, I’m quite sure, in this sophomoric attempt at analysis, he didn’t do a better job of quantifying cloud cover than the model-builders. Furthermore, I didn’t see any reference to what his regression analysis “predicted” for the last 17 years, but if he predicted anything at all, I guarantee you he didn’t get any closer to the real world than the models did.
Graeme W says:
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.
How these proxies are “calibrated” against both instrument data (some of which is of dubious quality) and each other?
All too often the issue of the “noise” being much larger in magnitude than any possible “signal” is handwaved away by warmists too.
Col Mosby says:
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.
There are a whole set of human activies which could have an effect on climate. Including some which have little or nothing to do with “fossil carbon”.
Pat Frank says:
Looking at the paper, the proxies in his Figure 5 are plotted at an accuracy of 0.1 C, implying 1-sigma = (+/-)0.05 C, for a paleo-temperature proxy that has no known physical relationship with temperature (except dO-18, which is never used in its physical sense in paleo-temperature reconstructions).
Figure 5 also plots the surface air temperature record without any error bars.
Figure 7 is plotted with an implicit claim of temperature accuracy of (+/-)0.02 C, and in the same figure Lovejoy claims to be able to detect a paleo-temperature natural variabilty of (+/-)0.2 C.
Would accuracy (and precision) in the centi-Celsius range be credible even using 21st century instruments? Both the Celsius and Fahrenheit scales originated in the 18th century so are there any useful temperature records as far back as the 16th?
The other issue with proxies is that they tend to indicate some sort of average over a period of time, Thus would completly miss any “spikes”.
I went back to reread the paper … and let’s be quite frank it is appallingly written.
However, the argument appears thus:
CO2 is expected to rise 1C for doubling.
This is a good proxy from manmade changes.
We think mankind has caused the equivalent of 2.3C I think is his figure.
If we scale up the CO2 by 2.3x the curves (vaguely) fit.
Therefore because (he can hammer a square peg into a round hole with a sledgehammer) it must mean all the 2.3 is manmade.
When he excludes as much natural variation as he can from climate models in what is clearly akin to the hockeystick handle approach (he may even use the same data) … he proudly announces that his results is unique.
“Unique is the word” … appallingly bad is also another.
If were Cinderella — and he were the ugly sister, yes he would be fitting the shoe to his foot …. but only by using a hacksaw to trim the foot to fit the shoe. (Or in this case blowing up the foot with botox).