Via Eurekalert and Wiley-Blackwell
The human cause of climate change: Where does the burden of proof lie?
Dr. Kevin Trenberth advocates reversing the ‘null hypothesis’
The debate may largely be drawn along political lines, but the human role in climate change remains one of the most controversial questions in 21st century science. Writing in WIREs Climate Change Dr Kevin Trenberth, from the National Center for Atmospheric Research, argues that the evidence for anthropogenic climate change is now so clear that the burden of proof should lie with research which seeks to disprove the human role.
In response to Trenberth’s argument a second review, by Dr Judith Curry, focuses on the concept of a ‘null hypothesis’ the default position which is taken when research is carried out. Currently the null hypothesis for climate change attribution research is that humans have no influence.
“Humans are changing our climate. There is no doubt whatsoever,” said Trenberth. “Questions remain as to the extent of our collective contribution, but it is clear that the effects are not small and have emerged from the noise of natural variability. So why does the science community continue to do attribution studies and assume that humans have no influence as a null hypothesis?”
To show precedent for his position Trenberth cites the 2007 report by the Intergovernmental Panel on Climate Change which states that global warming is “unequivocal”, and is “very likely” due to human activities.
Trenberth also focused on climate attribution studies which claim the lack of a human component, and suggested that the assumptions distort results in the direction of finding no human influence, resulting in misleading statements about the causes of climate change that can serve to grossly underestimate the role of humans in climate events.
“Scientists must challenge misconceptions in the difference between weather and climate while attribution studies must include a human component,” concluded Trenberth. “The question should no longer be is there a human component, but what is it?”
In a second paper Dr Judith Curry, from the Georgia Institute of Technology, questions this position, but argues that the discussion on the null hypothesis serves to highlight fuzziness surrounding the many hypotheses related to dangerous climate change.
“Regarding attribution studies, rather than trying to reject either hypothesis regardless of which is the null, there should be a debate over the significance of anthropogenic warming relative to forced and unforced natural climate variability,” said Curry.
Curry also suggested that the desire to reverse the null hypothesis may have the goal of seeking to marginalise the climate sceptic movement, a vocal group who have challenged the scientific orthodoxy on climate change.
“The proponents of reversing the null hypothesis should be careful of what they wish for,” concluded Curry. “One consequence may be that the scientific focus, and therefore funding, would also reverse to attempting to disprove dangerous anthropogenic climate change, which has been a position of many sceptics.”
“I doubt Trenberth’s suggestion will find much support in the scientific community,” said Professor Myles Allen from Oxford University, “but Curry’s counter proposal to abandon hypothesis tests is worse. We still have plenty of interesting hypotheses to test: did human influence on climate increase the risk of this event at all? Did it increase it by more than a factor of two?”
All three papers are free online:
Trenberth. K, “Attribution of climate variations and trends to human influences and natural variability”: http://doi.wiley.com/10.1002/wcc.142
Curry. J, “Nullifying the climate null hypothesis”: http://doi.wiley.com/10.1002/wcc.141
Allen. M, “In defense of the traditional null hypothesis: remarks on the Trenberth and Curry opinion articles”: http://doi.wiley.com/10.1002/wcc.145
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
Of course human activity can influence climate at least on a local level, eg urbanisation, deforestation, diversion of rivers, construction of dams etc. Whether man can have an effect on a global level is more moot although I would accept that high levels of emissions of soot can have such an effect.
However, that is no reason in itself to alter the null hypothesis. Anyone putting forward a theory should be expected to adequately prove his theory. If the claim is that man is altering the climate then those proposing it must prove it.
The human global warming hypothesis is a political one. It’s origin is from radical environmentalists trough UNEP and UNFCCC.
Once it was politically established in Rio in 1992 trough UNFCCC it’s purpose was that the debate was over and time was for action, radical change of the Western society.
It probably is one of the best examples in modern time of science beeing politics/ideology/policy driven.
When it should have been the other way around, politics and policy based on science.
Complete and utter desperation. Can’t prove that [you’re] an intelligent life form, state that [you’re] intelligent and get everyone else to prove [you’re] an idiot.
It makes me sad that this is what science has become. Once everyone knows what a bloody big scam this is and how climate ‘scientists’ politicians, bureaucrats, environmental groups etc have made a fortune out of this, then nobody will trust scientists again. Every time I hear a news item that starts with ‘scientists say’, I am immediately skeptical of the claims. Even though there are plenty of decent honest scientists, joe public will lump them into one group and have little respect for any of them.
I’ve long felt that the only possible result of the madness pushed by the climatology religion will be the destruction of real Science itself. And now we have one of the head climate celebutards stating it plainly for all the world to see. It should be no surprise though, we have heard similar over the years, for example about a year ago: “Julienne Strove from NSIDC asked last week what it would take to be convinced of man’s influence.“. That was also an example of turning the Scientific Method upside down and inside out (but keep in mind that compared to her boss Mark Serreze, she is practically tame).
The reversal of the burden of proof is one of the highest crimes in hard Science. It is like a medical doctor breaking the Hippocratic Oath. It is like a cop ignoring a crime. It is like Captains Kirk and Picard breaking the Prime Directive. In a more perfect world this Trenberth would be fired and his pension canceled and his University would cite him as a clear example of a Scientific failure. I wouldn’t address him as ‘Dr. for a million dollars (well check that, if he writes the check out to WUWT, Goddard, Lubos, Jo Nova and McIntyre I would bite my lip and use it).
This should be turned around on him quickly and with no mercy. Everyone should now pester all Scientists with a simple question: “Do you agree with Trenberth’s ridiculous assertion that Climate Science is settled and the Scientific Method no longer applies?“.
Hold their feet to the fire, DEMAND they answer and go on the record. That’s what the crooked mainstream media does all the time to their enemies. So let’s turn this issue into a positive! Ask Tamino, and John Cook, and Gavin and his comrades. Ask Mann, Suzuki, Princess Charles and Gore. And ask all the rest of the Climate Scientology prophets. At the very least we will have a clear picture of which one’s are vaguely acquainted with the core principles of Science, and those that are merely advocates masquerading as Scientists who must be rooted out.
“……..To show precedent for his position Trenberth cites the 2007 report by the Intergovernmental Panel on Climate Change which states that global warming is “unequivocal”, and is “very likely” due to human activities……”
Let me simplify what the good Doctor meant: ….global warming is “unequivocal”, and is “very likely” due to human activities because “we” wrote a document that says so….
Best,
J,
bob says:
November 3, 2011 at 10:32 am
“How does this work? The Trenberth gang says AGW is unequivocal, and writes the IPCC reports from that perspective. Then, Dr. Trenberth claims that AGW is unequivocal because the IPCC says so.
Is this circular reasoning, or what?”
Good one! Its so because he says its so!
The statistical attributions studies have to be big time in the tank with the recent “weather” data added in and the successes at Cloud 9. Back when they had a hockey stick and could claim that TSI variation was being overwhelmed by other forcings, they could ignore the 1920’s to 1940’s warming and attribute the warming of the 80’s and 90’s to manmade causes.
No doubt an inability to update attribution studies transparently has led to the desperate bid to try to quiet dissent when they come out with AR5 without updating this key work. One can determine that by simply looking at what Trenberth is working on today and its not that.
Now if we can just get Dr. Lonnie Thompson to give us a report on the Qori Kalis glacier in Peru, due to disappear in 3 months, from his most recent expeditions paid for with taxpayer dollars! That should go a long ways towards squelching dissent!
Trenberth has out travestied himself! He continues to live from the public purse and it is a travesty that he does.
Every time I hear a news item that starts with ‘scientists say’, I am immediately skeptical of the claims
“Humans are changing our climate. There is no doubt whatsoever,” said Trenberth.
“Really? Show me the observational evidence for that statement,” said Alice.
But answer came there none.
Trenberth needs to step down from his post, or be summarily removed. He is no longer coherent, and as such, is a significant liability to an agency of the US government. Regardless of his personal opinion, he is demonstating in open forum, that his rational, professional thought processes are failing. The US government no doubt has an abundance of employee assistance programs for senior executives who no longer are capable of controlling their behavior; he should enroll in one, immediately, and his employer should insist on it, immediately.
Trenberth is one of the best examples of “climsci*” I know.
*noun. a false or baseless person involved in CAGW. Those that deny important aspects or that rely on specious modeling or theory only; and those that are not fully scientists as they deny or distort the scientific method, typically for personal financial gain. Origin: Modern English clim, orig. climate, and sci, orig. science (combined contracted form).
R. Gates says:
November 3, 2011 at 4:36 pm
Kev-in-Uk says:
November 3, 2011 at 3:49 pm……………………..
As long as the shelves at Walmart are full of goodies with “low low prices”, none of this will attract the typical layperson’s attention.
——————————————–
I think this is called “rational ignorance.”
Alan Grey says:
November 3, 2011 at 4:42 pm
His stated Null hypothesis is wrong and evidence of the fuzziness of the whole field.
Logically, humans MUST have some effect on the environment. There is no chance this is wrong. Zero, zilch, zip, nada!.
It would be like creating a null hypothesis that 1+1 2.
—————————————————
So Alan, we’ve stopped talking about global warming and climate change. It’s now that we have “some effect on the environment.”
Moving targets are more difficult to hit
-Boy, being a skeptic is hard.
Rob Honeycutt says:
November 3, 2011 at 3:13 pm
Gail Combs… Actually the chart you’re attributing to Dr Spencer is the GISP2 ice core data and should be properly attributed to Dr Richard Alley. Dr Alley has clearly stated on many occasions that the GISP2 data is not a global proxy. It’s a regional proxy of the Greenland summit.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
It was Sarcasm not a “Scientific statement” (Note the /sarc> tag)
As far as I am concerned we do not have any really good data for CO2 or temperature outside of perhaps ARGO and Dr. Spencer’s Satellite data. Trying to say the temperatures rose 0.1C is misleading.
See AJ Strata’s error analysis: http://strata-sphere.com/blog/index.php/archives/11420
pochas says:
November 3, 2011 at 5:39 pm
The science is settled, therefore, the null hypothesis is void.
——————————
Science I’d say hypothetically, it’s null and void.
John Whitman says:
November 3, 2011 at 4:54 pm
“Prior to the posing of the null hypothesis is a process step involving observation of the aspect of nature you want to study.
Prior to that ‘pre null hypothesis’ observation of the aspect of nature you want to study is an even earlier process step involving formulating premises that give you reason to study that aspect of nature.
Prior to the selection of those premises is an even earlier process step of deciding what is objective scientific non-confirmation biased knowledge. How you know what knowledge is.”
You left out the step where one decides it is better to study a subject which will provide excellent funding than a subject for which funding is hard to come by.
You know we’re going to feel sorry for him sometime.
==============
Heh, I almost said ‘sometime soon’, but it’s too late.
==========
Blade says November 4, 2011 at 3:24 am:
“This should be turned around on him quickly and with no mercy. Everyone should now pester all Scientists with a simple question: “Do you agree with Trenberth’s ridiculous assertion that Climate Science is settled and the Scientific Method no longer applies? “
That’s a very good idea Blade but strike out the word “ridiculous” because if you do not – then you may be required to prove what part of it is ridiculous. – In which case “the burden of proof” is still on you.
Bob Armstrong says:
November 3, 2011 at 10:07 pm
re; “null” temperature of the earth
I like using empirical data if there’s any available as this always trumps theory. The measured average temperature of the moon is -23C or 249K. The was obtained by thermocouple in the regolith at depths greater than 100cm where temperature is constant year-round in two different mid-latitude locations. The albedo of the moon is 0.16 which is about the same as weathered asphalt. The earth’s surface absent atmosphere and ocean is the same as the moon as they are both the same basic rocks in the crust.
Ostensibly the moon is a bit colder because of the longer day/night interval which allows the surface to get hotter and the greater delta-T with cosmic background temperature of 3K means it will initially cool faster after sunset. I’m not sure how much and I’m not sure the claimed net effect is even true because the moon’s surface also gets much colder than the earth’s and then the delta-t is lower than the earth and heat loss slows. I’d bet it’s close enough to a wash to ignore the difference in day-length.
So there’s your null baseline taken from observation instead of calculation.
Personally I’d like the climate boffins, or someone, run the global circulation models with no ocean and see what happens. I’m betting the planet gets mighty cold mighty fast. It’s actually the ocean, not the atmosphere, that does most of the surface warming above the moon’s average temperature. The atmosphere need do no more than establish a surface pressure so there’s a 100C range above freezing where liquid water can exist in the first place.
DocMartyn says:
“Rob Honeycutt
. Dr Alley has clearly stated on many occasions that the GISP2 data is not a global proxy. It’s a regional proxy of the Greenland summit.”
“Just how many global proxies are there?
How does a lay-man differentiate between a global and local proxy?
Why is the ring width of one tree a global proxy of temperature, but one ice core a local proxy?”
DocMartyn… Any single proxy is always going to be a local proxy. Dr Alley has frequently made it very clear that GISP2 is a very poor indicator of global temperature.
Aunty Freeze says:
November 4, 2011 at 3:16 am
It makes me sad that this is what science has become. Once everyone knows what a bloody big scam this is and how climate ‘scientists’ politicians, bureaucrats, environmental groups etc have made a fortune out of this, then nobody will trust scientists again. Every time I hear a news item that starts with ‘scientists say’, I am immediately skeptical of the claims. Even though there are plenty of decent honest scientists, joe public will lump them into one group and have little respect for any of them.
_________________________________________________
That is exactly what is happening.
We had the climategate scandal and the Rasmussen poll says 69% Say It’s Likely Scientists Have Falsified Global Warming Research
Then in recent news we had
FDA finds U.S. drug research firm faked documents
Followed by the NYT article: Fraud Case Seen as a Red Flag for Psychology Research
This particular “picadillo” will really hit the average Joe because of the ruckus about schools and courts forcing The Drugging of Our Children (Also see Physicians Concerned About Ritalin Being Forced on School Children
This is a one – two – three knockout for the trust in science. Doctors and teachers have always had our highest trust and now we find the drugs they give us and our children are “questionable” We find the teacher/school committee who forcibly (with the courts backing) recommends putting our child on drugs, with life altering consequences, is doing so on the basis of a “science” whose notable expert faked the data.
http://familyrightsassociation.com/bin/white_papers-articles/drugging_our_children/#5
The love of money and praise has corrupted science, I am not sure whether the tarnish can be removed any time soon.
Richard Wakefield says:
November 3, 2011 at 5:11 pm
“I’m going to disagree with this for the following reason. All other disciplines of science have discovered that the universe works on its own. There is no god twittling knobs, there is no high being on a different plain than the unverse making things happen. Which is what the pre-science era thought about the world.”
I’m going to disagree with you for the following reason. Pagan religions like Greek and Roman had a multiplicity of whimsical gods. Judeo-Christian religion came along saying there was one rational God who created humanity in his own image. Thus the real beginning of western science, i.e. the enlightenment, was based on the tenet that a rational God created an orderly universe that operated according to laws and he populated it with rational beings fashioned in his own image who could study and understand the creation. Thus science is the study of God’s creation.
Dave Springer says:
November 4, 2011 at 8:18 am
Personally I’d like the climate boffins, or someone, run the global circulation models with no ocean and see what happens. I’m betting the planet gets mighty cold mighty fast. It’s actually the ocean, not the atmosphere, that does most of the surface warming above the moon’s average temperature. The atmosphere need do no more than establish a surface pressure so there’s a 100C range above freezing where liquid water can exist in the first place.
The figures are available. Without any atmosphere at all iirc it’s -18°C, with the atmosphere but without water the figure is 67deg;C. The water cycle brings down the temps dramatically through the water cycle, think deserts without the water cycle, evaporation taking the heat away from the surface via water vapour and in the colder higher levels this condensing out into rain and ice.