A challenge from Dr. Roy Spencer

From his blog http://www.drroyspencer.com/ which I’m repeating here to help get wide exposure.

A Challenge to the Climate Research Community

I’ve been picking up a lot of chatter in the last few days about the ’settled science’ of global warming. What most people don’t realize is that the vast majority of published research on the topic simply assumes that warming is manmade. It in no way “proves” it.

If the science really is that settled, then this challenge should be easy:

Show me one peer-reviewed paper that has ruled out natural, internal climate cycles as the cause of most of the recent warming in the thermometer record.

Studies that have suggested that an increase in the total output of the sun cannot be blamed, do not count…the sun is an external driver. I’m talking about natural, internal variability.

The fact is that the ‘null hypothesis’ of global warming has never been rejected: That natural climate variability can explain everything we see in the climate system.

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Robert Wykoff

A better challenge is to give just one weather/climate scenario that disproves global warming.

I can already tell you what the response will be:
“One study doesn’t prove global warming, HUNDREDS of studies taken together prove it as shown by the United Nations’ International Panel on Climate Change.”
Expand it out with useless filler and insert a few “deniers” and it’ll be Real Climate ready.

Scott Covert

I am understanding this challenge would not falsify AGW, only the assertion of “Settled Science” which is in itself an oxymoron.

Brian H

Roy, Roy, don’t you get it? They simply anoint AGW as the null hypothesis. They only part they get correct is the “null” part, of course.

Jack Greer

{scratch head smile}
This is just silly. Prove that the recent warming wasn’t caused by God hugging the Earth extra tight …

JinOH

Go get ’em Dr. Roy!! This should be interesting…

Scottish Sceptic

Disprove the null hypothesis?
you can’t expect them to do that … that’s like real science!

John in NZ

“He compared the efforts of financial journalists with the way crime reporters or foreign correspondents worked. He painted a picture of the outcry that would result if a legal correspondent began uncritically reproducing the prosecutor’s case as gospel in a murder trial, without consulting the defence arguments or interviewing the victim’s family before forming an opinion of what was likely or unlikely. According to Blomkvist the same rules had to apply to financial journalists.”
From the “Girl with the Dragon Tattoo” by Stieg Larrson.
When I read this I immediately thought of environmental reporters.
To talk of settled science is to admit incompetence.

KD

Brilliant. I look forward to the references. But I’m not holding my breath.

Laurie Bowen

If I’ve said it once, I’ve said it a hundred times . . . . and that ought to be enough . . .
22/7 = ? anyone . . .

Um, “scientific” paper, not “peer-reviewed” paper.
Presumably, one of the many “Hockey Stick” graphs would meet the criteria. If the climate were truly stable for the last 2000 years, and only in the last 30 has there been an abrupt rise, then I’d agree the warmists have something. The problem is that none of these papers are “scientific” in the classic sense. Most aren’t reproducible, a key requirement to be “scientific”. The rest aren’t robust, where a statistician can point out obvious flaws.
Presumably, any of the computer “Global Circulation Models” would meet the criteria. But computer models aren’t empirical evidence. They are a good way of coming up with theories, not proving theories.
Ultimately, would want is an “Old Science” proof of AGW, not “New Science” of irreproducibility, statistical hand waving, and computer models.

Dave

Jack Greer>
I think you’re missing the point. Sure, it’s a daft thing to ask for – unless ‘the science is settled’ in which case it should be there.

George E. Smith

“”””” Laurie Bowen says:
February 2, 2011 at 11:59 am
If I’ve said it once, I’ve said it a hundred times . . . . and that ought to be enough . . .
22/7 = ? anyone . . . “””””
3+/-50%

Jack Greer

Robert Wykoff said February 2, 2011 at 11:32 am:
“A better challenge is to give just one weather/climate scenario that disproves global warming.”
=========
Of course. Frustration seems to have pushed Dr. Spencer beyond his own tipping point.

George E. Smith

3.1’4’2’8’5’7′

Show me one peer-reviewed paper that has ruled out natural, internal climate cycles as the cause of most of the recent warming in the thermometer record.
Show me one peer-reviewed paper that has ruled out experimentation by little green aliens as the cause of most of the recent warming in the thermometer record.

cochrane

I was having a discussion by email with a professor of astronomy, I had read his review of “Heaven and Earth” by Ian Plimer. This appeared in the Australian some years ago, but I didn’t get round to reading it until recently. The review was so totally biased and so utterly unfair that I could not resist sending an email to the author.
One thing I said was – science in never settled, I quoted the issue of peptic ulceration. Two doctors in Western Australia produced the idea that peptic ulceration was due to infection rather than gastric acidity. The overwhelming consensus at the time was that acid, or acid plus certain enzymes, caused ulcers. The West Australian doctors were laughed to scorn. They now hold a Nobel Prize.
The astronomy professor replied thus. This is not verbatim, but the sense has been retained.
Science is science. And good science will always triumph over bad science. There was no evidence whatsoever to support the acid hypothesis. The West Australian doctors did an experiment which proved that the rubbish their peers believed was wrong. They were quite rightly awarded a Nobel Prize.
The level of consensus within the climate science community is much stronger than that within the medical community. Because of this, climate science is more soundly based than medical science.
This is good thinking from a professor of astronomy. I don’t think that even a professor of theology could have done any better.
Let’s us look at the man- made global warming hypothesis from the point of view of medical science…
The system which almost all doctors accept today is the Cochrane system. Briefly, the Cochrane system works as follows.
The strongest level of evidence is level one.
Level one evidence consists of randomised controlled trials under extremely stringent conditions.
The next level of evidence is level two.
Level two evidence again consists of randomised controlled trials, but under less stringent conditions.
Next comes level three.
Level three evidence consists of observational studies.
Even if the series studied is large and the correlation is tight, an observational study can never prove a hypothesis. Correlation does not prove causation. An observational study might suggest that a hypothesis is “reasonably likely” But the proof lies in the randomised controlled trial. Preferably this trial will have reasonably large numbers of patients and have the tight parameters of level one.
Consensus gets low marks under Cochrane. Cochrane is about evidence rather than opinion. A single opinion has an evidential value of zero. Consensus might represent the opinion of 3,000 people. Multiply zero by 3,000 and the answer is still zero.
Now let’s look at man made global warming.
We can’t have a randomised controlled trial. We have one patient (planet earth). We don’t have even one single other planet to put in the control group.
So let’s do an observational study.
An observational study with one patient is not an observational study. It is an anecdote, or at best a case report.
OK, let’s be practical. We only have one planet earth, so our single patient is very, very important to us.
Since planet earth is so precious to us, we are prepared to accept an observational study with a tight observed correlation as being evidence enough to act on.
We have to look at the degree of correlation over four time periods.
There is the period 1900 to 1945. During this period the planet warmed.
Compared to today, there was not much in the way of heavy industry. There were very few cars on the road. Not a lot of CO2 was produced… But the planet warmed. 1938 may not be the hottest year ever recorded, but it fits comfortably into the top 10. I think that it is very reasonable to say that the warming seen from 1900 to 1945 was not due to carbon dioxide. We were coming out of an ice age.
Now let’s look at the period from 1945 to 1975. We are in the era of post war recovery. More cars are being built. More electricity is being generated. More heavy industry is starting up. More CO2 is being produced. But the temperature is in fact going down. How do we explain this? The IPCC says pollution with substances such as sulphur dioxide were the cause of the fall in temperature over this period.
Now this is an assertion. There are no quantitative measurements of all the aerosols and other pollutants and computer models of how each pollutant would affect the climate. But lets be generous. Lets say that there is a seventy five per cent chance that this explanation is correct.
Now we move on to the period from around 1975 to 1998. Her we have a period when a further rise in atmospheric carbon dioxide is associated with a further rise in temperature. There arte alternative explanations. It could be the sun. It could be something that we haven’t thought of yet. But let us be generous and say we are 90% certain that global warming from 1975 to 1998 was caused by man made carbon dioxide.
Then we reach the period 1999 to 2010. We continue to produce lots of carbon dioxide. There is no statistically significant rise in temperature during this period.
But the warmists say that this 11 year period contains three, or five or six of the warmest years on record.
Well the temperature has been rising by fits and starts for about 150 years. We are on a high plateau, so it is not surprising that some of the temperatures we see are record ones. But are we going to stay on that plateau? Are we going to start moving gradually downwards in terms of temperature? Or are we about to take off with the climate getting warmer still?
Well, of course, there is no way in which this question can be answered with any certainty. But lets be generous again. Let us say that the fact that several of the years of the last decade are in the top 10 ever recorded means that there is a 70 per cent chance that this period of time supports man made global warming.
OK the global warming hypothesis rests on three lines of evidence.
The first line of evidence has a 75% chance of being correct.
The second line of evidence has a 90% chance of being correct.
The third line of evidence has a 70% chance of being correct..
If you roll a dice once, the odds against guessing the right answer are six to one.
If you roll the dice three times the odds against you getting the right answer three times running are six to one multiplied by six to one multiplied by six to one.
The odds against you are 216 to one.
The odds in your favour are the reciprocal of this. They are 0.00463.
Now we have three lines of evidence for the man-made global warming hypothesis.
The odds in favour of each piece of evidence are, respectively 75%, 90%, and 70%
Multiply 0.75 by 0.9 then by 0.7 and you get 0.475.
There is a 47.5% chance that the hypothesis is correct.
Does this show that the science is settled? Don’t make me laugh.
I have no idea what the temperature will be like in 100 years time. Neither has the IPCC.

latitude

You’re my hero………..

Dr T G Watkins

It is extraordinary that, with the economic and energy consequences of cAGW theory, the governments of the developed nations have not demanded a conference in which both sides of the debate present and evaluate the evidence for their positions.
Attendance should be mandatory so that no-one could avoid the cross examination and conducted in the spirit, not of Lisbon, but perhaps of Solway 1927.
Let the facts and the evidence decide.

stephen richards

Jack Greer says:
February 2, 2011 at 12:07 pm
Robert Wykoff said February 2, 2011 at 11:32 am:
“A better challenge is to give just one weather/climate scenario that disproves global warming.”
=========
Of course. Frustration seems to have pushed Dr. Spencer beyond his own tipping point.
My god the trolls have been dragged from under the bridge. Get your act together you guys. Read Trenberth et al they are far better at deflecting the question from the climate science is settled scenario.

CRS, Dr.P.H.

McShane & Wyner are not quite what you are seeking, Roy, but they did shake things up quite a bit!
http://climateaudit.org/2010/08/14/mcshane-and-wyner-2010/
It will likely take years for the type of scientific evaluation you seek to see the light-of-day, although there might be something in the Russian literature. Would that count?

Colin in Mission BC

“What most people don’t realize is that the vast majority of published research on the topic simply assumes that warming is manmade.” – R.Spencer
This phenomenon drives me absolutely batty. How many thousands of studies have been done, with time, money and resources spent, that operate along the lines of such-and-such species displaying such and such behavior in the context of global warming?
All of these studies are absolute garbage, all those resources wasted, since the underlying assumption (that AGW is real) is a myth.
=====
Incidentally, Dr. Spencer, I downloaded your book “The Great Global Warming Blunder” to my Kindle the other day. I’m enjoying the read immeasurably.

Dave

AGW/Climate Change is not science but alchemy. An endeavour to turn CO2 into Au.

Ray

AGW is a belief system that does not need to be proven. You just need faith. It is exactly the same thing with God. There are never been any peer-reviewed papers on the existence of God. The whole thing is based on a bunch of gray literature papers (dead sea rolls) that they conveniently put together and named it Bible. Not an once of science in it, yet people always killed each other to impose their belief system.

Boris

This is just silly. Even the IPCC report doesn’t “rule[] out natural, internal climate cycles as the cause of most of the recent warming in the thermometer record.” It is simply extremely unlikely.
Might as well ask for a biology paper that rules out the possibility of God.

eadler

Roy Spencer says:
Show me one peer-reviewed paper that has ruled out natural, internal climate cycles as the cause of most of the recent warming in the thermometer record.
From what I understand, the GCM’s show that without GHG’s from human sources, the increase in global average temperature can’t be explained. Look at the 3 graphs showing an ensemble of simulations on this page:
http://www.skepticalscience.com/climate-models-intermediate.htm
The graph with only natural forcings cannot explain the recent temperature increase. So this is one scientific study.
No one doubts that what appear to be internal cycles, have a strong influence on climate. However human influence through GHG’s and land use, has the capability to modify these internal cycles according to most scientists. So the observation of natural cycles determining climate doesn’t disprove the hypothesis that GHG’s are changing the climate of the globe.

Here is the question to put to the warmists: why are you guys still using global temperature curves of questionable and secretive origin if accurate satellite temperature measures have been available for thirty one years? They cover the globe and both hemispheres uniformly, are not affected by the urban heat island effect, and have been calibrated against radiosonde values. You will get a variety of answers but the real answer is this: they use their own secretive sources because their temperatures are cooked. As in falsified. I will be specific: what these secretive curves from NOAA, NASA, and the Met Office show is a period of warming in the eighties and nineties that is not present in the satellite record. Why is this so important? you may ask. The answer is that in 1988, right smack in the middle of this period, Hansen stood up in front of the Senate and testified that global warming had started. That was simply a lie as satellite temperature records show but his testimony became the founding event of the global warming movement we have today. If they admit the truth they will have cut the legs out from under this founding event of their religion. To find out how these temperatures were faked, get my “What Warming?” (second edition) and check out figures 15, 24, 27 and 29.

Scottie

The most persuasive argument for AGW that I’ve heard so far goes along the lines of, “Do you think we can go on pumping tonnes of CO2 (anyone seen a CO2 pump?) into the atmosphere without it having an effect?”
It seems that personal incredulity is an accepted proof in climate science.

-=NikFromNYC=-

Why invoke natural variability when natural regularity will do, namely a smooth linear warming trend going back 350 years as directly measured by real thermometers in the world’s classic old cities? I plotted them in postcard format: http://oi49.tinypic.com/rc93fa.jpg
Finding these old records was the end of my interest in active debate. Neither side seemed very interested when I started posting this basic data in the days leading up to Climategate. How can history be a Hockey Stick if single site thermometer records failed to show even a hint of noticing?

Kev-in-Uk

Am a bit puzzled – many have said the same thing over the last few years – I know I have/did, once I started to actually look into the actual claims of AGW. It is a basic understanding of the scientifically minded skeptics (I believe) in that most enquiring minds do not take the ‘assumptions’ as always being valid and, as described , most of the AGW theory is based on various assumptions.
In short, I can’t see anyone accepting a challenge for something that doesn’t currently exist. If it did, as has been mentioned many times before, we wouldn’t be discussing the subject in the same manner!

Mainstream will say
(1) CO2 is a greenhouse gas – all agree
(2) human emissions clearly track CO2 rise – this seems self-evident
(3) isotope content proves the CO2 rise is manmade
(4) it cannot be the Sun (directly) because there’s too little variance – all agree
They can produce peer-reviewed papers “proving” (3). They will fail to mention papers that dispute (3) with equal or better science. They will fail to mention Bob Carter’s classic dismissal which shows that the recent rise, and rate of rise, of temperature, are both well within natural limits – if we look properly at the past.

Dave N

“One study doesn’t prove global warming, HUNDREDS of studies taken together prove it as shown by the United Nations’ International Panel on Climate Change.”
Those studies are exactly what Dr Spencer is talking about; they all assume human caused warming and not one rules out natural variability. Having said that, I’m sure RC would still give that as an answer and delude themselves into thinking they’ve satisfied the question.

Scottish Sceptic

Laurie Bowen says: February 2, 2011 at 11:59 am
22/7 = ? anyone
22/7 = 2.22222 ….(recurring)
Which unless I’ve made an awful mistake in the maths is really true!

Pay attention to this paper, folks! Is Nature making a U-turn?
Late Holocene methane rise caused by orbitally controlled increase in tropical sources
Joy S. Singarayer, Paul J. Valdes, Pierre Friedlingstein, Sarah Nelson & David J. Beerling
Nature 470, 82–85 (03 February 2011) doi:10.1038/nature09739
This paper reminds me of the often-neglected work of Gerard Roe (Motl discussed it once), Anthony, will you please devote a post to this topic?
Roe, G. (2006), In defense of Milankovitch, Geophys. Res. Lett., 33, L24703, doi:10.1029/2006GL027817.

Robert Wykoff says:
February 2, 2011 at 11:32 am
A better challenge is to give just one weather/climate scenario that disproves global warming.

Well, first one would have to prove that our temperature measuring capabilities are accurate enough that we can determine either a cooling or warming trend. Then one would have to agree on the length of time to use to determine whether there has been either a cooling or warming trend.
Even so, if we accept that we have been in a globally warming trend since, say, the end of the LIA, then I fully agree with Dr. Spencer – the onus is on the claimants that any of the warming is anything but natural. The claim has been made: anthropogenic CO2 is causing warming on a global scale. Now the claimants must show how it is causing the warming and show that the warming is outside of natural causes. Once that is done, others can analyze the claim and either agree or disagree.
In the simplest terms – if I were to flip a coin, and cover it up so no one can see it, and claim that it is heads and therefore you owe me a great sum of money, would you give me the money or would you want to see the coin first? What I see a large number of AGW by CO2 supporters doing is accepting that the coin is heads without seeing the coin.
Spencer, Watts, McIntyre, McKitrick, etc. are asking (demanding) to see the coin.
They should not be required to prove that there is no coin or that the coin is not heads.

Jeremy

There is no such paper, Dr. Spencer.
If there were such a paper, the IPCC would have championed it far more than the hockey stick. McIntyre & McKitrick’s work would be entirely ignored if such a paper existed. All skepticism about the temperature record, the positive feedback caused by CO2, the dominance of clouds, the stability of the suns influence would all not exist to the degree they do if any such paper existed.
There is no such paper.

Scottish Sceptic

Lucy Skywalker says: February 2, 2011 at 12:36 pm
“Mainstream will say ….”
The simple answer is that if you look at the IPCC report, you will see that the natural variation present is a type of 1/f type noise which is a kind of noise doubles for every doubling of the period over which you measure it. So, if the noise amplitude is 0.05C/decade, it is 0.1C/2o-years 0.2C/40years and 0.4C/80-years and 0.8C/160-years.
So, it is very easy to measure the amplitude of this 1/f noise prior to extensive CO2 and compare it that afterwards, and the result is that the change we have seen is entirely compatible with natural noise.
That is how it is done, that I suggest is why there is no paper checking this – because anyone who did it found it disproved the whole basis of man-made global warming!

Jeremy

Lucy Skywalker says:
February 2, 2011 at 12:36 pm
(3) isotope content proves the CO2 rise is manmade…
They can produce peer-reviewed papers “proving” (3).

I still don’t quite buy this isotope content “proof”, btw. Has anyone studied the isotope content of the dissolved CO2 in the ocean at all depths to eliminate it as a source? Has anyone completely ruled out cosmic influence on altering the carbon isotope content of the atmosphere (cosmic rays do this)? To me, this avenue seems ripe for a major smackdown, but perhaps I just haven’t read the right papers. 🙂

TomRude

OT: Steig has a some new comment on O’Donnell at RC.

first you have to state the null in a quantitative manner.
But failing that, we have some examples of things never seen before. The problem with the “null” as Spencer states it, is that he doesnt specify what that null is exactly.
Further and more importantly there are events that do not trangress the bounds of “natural variability” that can be explained by mechanisms. Volcanoes do not cool the atmosphere outside the bounds of natural variability, BUT we dont attribute the cooling to natural variability. Simply the existence of natural variability says nothing about the effects one will see from more C02 in the atmosphere.
But on to an example of the null being found inadequate: here on WUWT
http://wattsupwiththat.com/2010/06/01/the-ice-who-came-in-from-the-cold/
As I noted this data challenges ‘the null’
Steven mosher says:
June 1, 2010 at 10:46 pm
Dunno, looks like an issue for the null hypothesis. ice cycling like its never cycled before.
Willis, caretaker of ‘the null’ agrees
Willis Eschenbach says:
June 2, 2010 at 12:00 am
Steven mosher says:
June 1, 2010 at 10:46 pm
Dunno, looks like an issue for the null hypothesis. ice cycling like its never cycled before.
It would … if I thought it was real. I don’t, I think it is from the known change in the satellite and the way that is being dealt with by means of a new algorithm.
w.
BUT he thinks the algorithm must have changed.. rejecting the data.
I think:
Steven mosher says:
June 2, 2010 at 9:28 am
Willis:
“Me, I think this new pattern reflects a change in satellites, or a change in procedures, or something like that. But hey, I’ve been wrong before”
on what evidence? you have the data. It indicates a divergence from past normal behavior. It challenges the Null. I wouldn’t think the first response is to challenge the instrument on no colorable basis. but hey, its climate science. Now surely, we must accept the data and in the absence of any concrete evidence that the instrument is bad, we cant speculate that the instrument might be bad. As I pointed out, that would be exactly like the special pleading that Briffa did WRT his divergence problem.
So, I find the actual instrument for him and he promises to write the scientist.
“Good find, Mosh. I’ll take a look and see what’s going on there. I’ve written to Dr. Bilitza to see what I can find out.”
And 7 months later we still have no update.

stephen richards

cochrane says:
February 2, 2011 at 12:11 pm
Dice rolling is an independent probability at each throw. The odds remain the same no matter haw many times you throw the dice. Each throw cannot influence the next unless you eliminate the previous number and then the odds get better on you being right. Did I miss soemthing ?

Theo Goodwin

Wonderful challenge, but issue one more. Challenge them to present one physical hypothesis that is reasonably well-confirmed and that can be used to explain and predict some so-called positive forcing. There is not one. Climate scientists cannot pull themselves away from their computers long enough to look out the window. At this time, there is no empirical science of forcings.

Cross-posted on Roy’s site:
No, but I can point to peer-reviewed papers that indicate that we still have a limited understanding of Earth’s natural variations, which makes it impossible to “rule them out” as a potential “cause of most of the recent warming”.
For example, Polar Vortices:
“Many atmospheric general circulation models (GCMs) and chemistry–climate models (CCMs) are not able to reproduce the observed polar stratospheric winds in simulations of the late 20th century. Specifically, the polar vortices break down too late and peak wind speeds are higher than in the ERA-40 reanalysis. Insufficient planetary wave driving during the October–November period delays the breakup of the southern hemisphere (SH) polar vortex in versions 1 (V1) and 2 (V2) of the Goddard Earth Observing System (GEOS) chemistry–climate model, and is likely the cause of the delayed breakup in other CCMs with similarly weak October-November wave driving.”
“In the V1 model, the delayed breakup of the Antarctic vortex biases temperature, circulation and trace gas concentrations in the polar stratosphere in spring. The V2 model behaves similarly (despite major model upgrades from V1), though the magnitudes of the anomalous effects on springtime dynamics are smaller.”
“Clearly, if CCMs cannot duplicate the observed response of the polar stratosphere to late 20th century climate forcings, their ability to simulate the polar vortices in future may be poor.”
http://meetingorganizer.copernicus.org/EGU2009/EGU2009-651.pdf
http://adsabs.harvard.edu/abs/2010JGRD..11507105H
“It is unclear how much confidence can be put into the model projections of the vortices given that the models typically only have moderate resolution and that the climatological structure of the vortices in the models depends on the tuning of gravity wave parameterizations.
Given the above outstanding issues, there is need for continued research in the dynamics of the vortices and their representation in global models.”
http://www.columbia.edu/~lmp/paps/waugh+polvani-PlumbFestVolume-2010.pdf
Or how about the Thermohaline Circulation:
“One of the “pumps” that helps drive the ocean’s global circulation suddenly switched on again last winter for the first time this decade. The finding surprised scientists who had been wondering if global warming was inhibiting the pump and did not foresee any indications that it would turn back on.
The “pump” in question is in the western North Atlantic Ocean, where pools of cold, dense water form in winter and sink beneath less-dense warmer waters. The sinking water feeds into the lower limb of a global system of currents often described as the Great Ocean Conveyor. To replace the down-flowing water, warm surface waters from the tropics are pulled northward along the Conveyor’s upper limb.”
http://www.whoi.edu/page.do?pid=12455&tid=282&cid=54347
http://www.nature.com/ngeo/journal/v2/n1/abs/ngeo382.html
We have a rudimentary understanding of Earth’s climate system. We cannot eliminate potential variables when we do not understand them, cannot effectively measure them and, in some cases, do not yet know that they exist.

stephen richards

Lucy Skywalker says:
February 2, 2011 at 12:36 pm
The CO² isotope one always gets me. Are they saying that C13 cannot be produced by any other means other than combustion ? If so I would want to see a very definitive proof. It after all only a matter of energy isn’t it?

Theo Goodwin

Robert David Graham says:
February 2, 2011 at 12:03 pm
“Um, “scientific” paper, not “peer-reviewed” paper.
Presumably, one of the many “Hockey Stick” graphs would meet the criteria. If the climate were truly stable for the last 2000 years, and only in the last 30 has there been an abrupt rise, then I’d agree the warmists have something.”
But it doesn’t meet my criteria, which I will restate as follows:
Identify one physical hypothesis that is reasonably well-confirmed and that can be used to explain and predict some positive forcing. There is none. Therefore, there is no empirical science of forcings.

juakola

@Leif:
So I suppose you didnt have the paper, which proves that climate is stable without external forcings influencing it, right?

stephen richards

JohnWho says:
February 2, 2011 at 12:40 pm
Robert Wykoff says:
February 2, 2011 at 11:32 am
A better challenge is to give just one weather/climate scenario that disproves global warming.
Far more intellectual than I. I like you example very much.

Theo Goodwin

Colin in Mission BC says:
February 2, 2011 at 12:21 pm
“Incidentally, Dr. Spencer, I downloaded your book “The Great Global Warming Blunder” to my Kindle the other day. I’m enjoying the read immeasurably.”
This book is a science classic and is the best book or article published in climate science. Its conclusions should be the starting point for all discussions of AGW.

WheelsOC

I would pose to Dr. Spencer a counter-challenge, that he publish one peer-reviewed paper that convincingly establishes natural, internal climate cycles as the cause of most of the recent warming in the thermometer record. But Dr. Spencer has said he doesn’t want to publish in the peer-reviewed literature anymore and prefers more laxly refereed venues like Geophysical Research Letters. It seems a bit hypocritical to demand peer-reviewed rebuttals to his non-reviewed assertions. That’s not how the burden of proof works.

RockyRoad

Right in the smack-dab middle of the biggest snowstorm in the history of the planet you’re expecting AGW’ers to drop their snow shovels, doff their fur-lined hats, take off their gloves and parkas, laboriously remove their snow-encumbered boots and write something in FAVOR of global warming?
Surely you jest; I see no takers.