Leading climate scientist: IPCC forecasts could be too warm.

Huh, an (at first pass) apparently honest bit of science for once from the climate establishment.



It's certainly interesting and it's good that he ties the uncertainty to clouds -though he stops short of applying the same uncertainty to clouds themselves (which also insert warm bias into the models).



Amusingly, doesn't this present a catch22 where we need to reduce co2 emissions from fossil feul production to halt cAGW, but need the other emittants to help stave off the current cAGW :-)



I was initially dismayed by Cameron and Huhnes plans to tie the UK to ever Hhigher C02 reduction schemes, yet on closer inspection it seems that the 'targets' are so riddled with political loopholes and get-out causes that i'd need'nt have bothered getting worried. A political gesture- nothing else.



Back to the main point however, now the first 'stone' has been removed from the IPCC-Model 'wall' i wonder how long before people finally realise that they're largely, crock?



This, coupled with the early CERN results seem to throw some rather serious issues up for the IPCC and the 'consensus' science.



We live in interesting times.

I'm pleased that James Hansen appears to agree with me that IPCC models may be too high!

However, the last two paragraphs seem to be contradictory. One implies that temperatures could rise sharply, and the second that they might rise less quickly.

However, the research does seem to explain why temperatures model predictions have been too high, but allows for the possibility that the models may be correct in the future.

Guess I am going to have to read the research!

I don't remember reading about this anywhere else, and the research was published at the start of May. I would have thought it might have caused quite a stir. Thank you for highlighting it Paul, I suspect this could be a lively blog again!

Dr Spencer has posted some fascinating thoughts on direct and indirect solar forcing following the recent news over GCRs. He's made some rough and ready calculations which are offered cautiously and says that he may now have to consider a re-think for both total solar forcing and mechanism.



Interesting times indeed Labmunkey. . . .

Interesting.

I guess it is only a presumption that global levels of aerosol pollution will fall in the future. From the prism of the western world we get the impression that air quality is improving, but pollution in many developing countries is appalling and seems set to get worse. I believe there is a huge "brown cloud" over much of south Asia visible even from space, for example.



Even so, that the climate might become hostage to two forms of major man made pollution is hardly a comforting thought - whether it results in warming, cooling or even some sort of precarious balance.

All the money wasted on CO2 mitigation, and finally they start leaking out material they will eventually use to defend themselves when the wheels finally come off cAGW.



In the meantime this "rush to green" is causing just as much damage to the environment as the industry it rails against:



https://notrickszone.com/2011/05/19/biogas-plants-producing-deadly-botulism-could-be-catastrophic-to-wildlife/



Meanwhile polar bears continue to not decline, temperatures continue to not rise anywhere near even the lowest estimates, sea level rises are lower than at anytime in the last century, etc., etc.



Time for a new scam guys, this one is looking a little threadbare.

Oh Dear. The carbon emission /climate change delusion continues - a milestone in the history of human stupidty. REAL climatologists, like Prof Robert Parker, have pointed out the flaws in the THEORY based on computer models by the University of East Anglia. Human carbon emissions have no significant effect on climate at all but a very slight beneficial effect by encouraging plant growth, Get your camping gas stoves and solar powered lamps ready for the power cuts that will result from the the government's expensive folly

Following on from weapons of mass destruction we now find out that it was a set up by certain people in the establishment to get their own way and go to war and the secret service say that Saddam was never a threat to us. Similarly we have people trying to take action that isn't necessary to reduce Co2 to 60% of 1990 levels, that will kill the competitiveness of our industry, while countries like India, China, America etc will carry on regardless. I think we need an court enquiry into this now, before we do untold damage to our country for no reason.

Good lord it seems no one, including Paul, actually read the study, and the result is complete misinformation. First off, it confirms that models are in agreement with observations, contrary to what Paul claims.



Second, it says that while negative aerosol forcing has been underestimated by the models, the models also overestimate the response function of the ocean, so that the effects happen to largely cancel out (thus, the model-observation agreement).



From the study:



"Our derived aerosol forcing does exceed aerosol forcings employed in most climate simulations carried out for IPCC (2001, 2007). For example, an ensemble of models from several groups (Fig. 9 of Stott and Forest, 2007) had aerosol forcings in the range ‒0.4 to ‒1.1 W/m2. Our interpretation of why these models produced agreement with observed temperature change over the past century is that the ocean models have a slow response function, slower than the real world, mixing heat too efficiently into the deep ocean."



Lastly, the study certainly does not declare future projections too warm. On the contrary, it infers the opposite. If models have underestimated negative aerosol forcing and overestimated ocean heat uptake, this implies that future projections are underestimated. The reason is because sulfate aerosols are projected to decline. If the negative effect has been stronger than expected, this implies greater future warming. In addition, if oceans respond faster than models indicate, this also indicates faster warming.



There are other notable conclusions:



"This dominance of positive climate forcing during the solar minimum, and the consistency of the planet's energy imbalance with expectations based on estimated human-made climate forcing, together constitute a smoking gun, a fundamental verification that human-made climate forcing is the dominant forcing driving global climate change."

MarkB2020: If you care to look at IPCC model projections, then they have been for years consistently too high. You imply that models are in agreement with observations when this plainly hasn't been the case.

@Paul Hudson



Paul,



I feel I should point out this paper is neither peer-reviewed nor published



(Please, please, please keep the current blog format!)



/Mango



I don't deny climate change, I know climate changes

Congratulations to MarkB2020 for beating me to it! I am extremely disappointed that Paul Hudson made this post without first checking the DETAIL of the Hansen et al article (as far as I can see it isn't a peer-reviewed paper at present).



Mark is absolutely correct - at no point does Hansen suggest that the models are overstating the warming. What he is actually implying is that they are producing accurate projections but for the wrong reason!



In fact, the idea that the IPCC's estimate of aerosol forcing may be a bit low is not new. Other papers, notably one by Murphy et al, found the same. However, there is considerable uncertainty because it is not easy to physically measure. Instead it is derived from energy balance studies by assuming that it constitutes the difference between the amount coming into the system from space and the amount accumulating in the system. There are 2 problems with this:



The resolution of the satellites is poor, so although it is possible to say for certain that the Earth is accumulating heat, the confidence limits around the figure are large.



Energy balance studies also crucially rely on ocean heat content estimates. The new Argo system does measure this better, but coverage is still not complete (especially at high latitudes) and it may well not be picking up heat accumulating at the greatest depths.



So the higher negative aerosol forcing proposed here by Hansen may simply be an artefact of the method used to estimate it.



Certainly, those hoping that AGW is in doubt should take no solace from this paper. It's just a shame that it takes people such as Mark and myself to read it properly and correct misinformation being spread around the internet.



Paul

Paul Briscoe - you say that the research says that climate projections are right for the wrong reason? Putting on one side the fact that IPCC forecasts have been too high, and it has been evident for some time to those who care to look, how can we take confidence in any projection that is seen to be OK because it's right for the wrong reason? It's absolutely unacceptable, and from a scientific point of view, to borrow a word from the author, untenable.

#12. - Paul Briscoe wrote:

"Mark is absolutely correct - at no point does Hansen suggest that the models are overstating the warming. What he is actually implying is that they are producing accurate projections but for the wrong reason!"

Apart from the fact that the models are NOT producing accurate projections (unless you include projections of past figures, in which case it's probably the wrong word), any actual accuracy in the projections seems to be more a matter of chance than anything else. I think in the field of accountancy, that would be known as "compensating errors".

I haven't had a chance to read the full article yet, but the following sentence from the abstract seems to suggest that the models may have a bias towards warming:

"We conclude that most climate models mix heat too efficiently into the deep ocean and as a result underestimate the negative forcing by human-made aerosols."

Unless, of course, the above is offset by overestimates of the positive forcing from greenhouse gasses.

If the paper is neither published nor peer reviewed, what is it's status. Is it awaiting peer review prior to publication?

QV (and this applies to Gadgetfield too).



You and I are going around in circles here!



You are basing your claim that global temperatures are falling short of projections on FAR too short a period. As I pointed out in the previous thread, Gavin Schmidt clearly stated that the models are not designed to allow for short term (less than 15 years) deviations due to effects such as ENSO and the recent extended and deep solar minimum. If temperatures are still below projections in 10 years time you will have a point.



"If the paper is neither published nor peer reviewed, what is it's status. Is it awaiting peer review prior to publication?"



I honestly have no idea about that! My guess is that it is a discussion piece. Maybe it will be written up into a paper in due course.



Paul

status of paper . . . another sticking plaster methinks

Gadgetfield @ #13



"how can we take confidence in any projection that is seen to be OK because it's right for the wrong reason?"



This is hugely complex science and the scientific community (contrary to claims by sceptics) make no secret of the uncertainties. However, there is also an awful lot that they DO know and they have built all available knowledge into the models.



The fact is that you can start the computer models running in the early 20th century, feeding in only the forcings from past data and they can accurately project what happened to global temperature throughout the 20th century. So even though not every aspect of the climate system is fully understood, the models are clearly showing the correct "sensitivity" to the combined effect of all the forcings. Furthermore, there is lots of evidence from paleoclimate data that climate sensitivity is within the range stated by the IPCC and NOT much lower as claimed by a small handful of scientists.



Let's consider an analogy.........



After Sir Isaac Newton proposed the theory of gravity, models were constructed which allowed scientists to predict where particular planets would be at a particular time. Gravity has never actually been directly measured and assumptions had to be made in the models, yet they still proved able to make very accurate predictions.



In more recent times, with Einstein's Theory of Relativity, our understanding of gravity has completely changed and the scientific assumptions on which those early models were based would now be considered flawed...... but the fact remains that the early models are STILL capable of making very accurate predictions!!



The fact is that science generally progresses in small steps and scientists have to make the best of knowledge available at any particular point in time. Your apparent expectation that they should fully understand every aspect of the climate system before doing anything is wholly unrealistic.



Paul

timawells @8

"I think we need an court enquiry into this now, before we do untold damage to our country for no reason."



Don't even think about going there!

There are a group of students in USA trying to take a case through the courts and they have Hansen as a supporting witness. The bottom line is that where there is a lack of irrefutable evidence, a court would take into account the professional standing of the expert witnesses and the consensus views of the relevant professional scientific bodies.

No brainer - AGW would win the day.



The recent, various inquiries following 'climategate' show how the drafting and subsequent interpretation of the remit can essentially make the inquiry pointless.



For a clear definition of the role of full public inquiries, please watch yes minister.

#15. - Paul Briscoe wrote:

"You are basing your claim that global temperatures are falling short of projections on FAR too short a period. "

Unfortunately, it's the only period we have!

"If temperatures are still below projections in 10 years time you will have a point."

Surely your not seriously suggesting that the IPCC model projections should remain as they are in AR5?

#17. - Paul Briscoe wrote:

"The fact is that you can start the computer models running in the early 20th century, feeding in only the forcings from past data and they can accurately project what happened to global temperature throughout the 20th century."

As I have previously attempted to point out, this is a logically flawed argument.

If the models hadn't accurately "projected" the 20th century temperatures, we wouldn't know about them. It would be possible to devise models based on random forcings, some of which would, by sheer chance, accurately "predict" past temperatures. That doesn't mean they will accurately predict future temperatures.

You will at least acknowledge that the models are less accurate for the future than they are for the past. That should start alarm bells ringing.

I would only change this view if I could be convinced that the models had not been "tested" on past data and adjusted in order to make the past "predictions" fit actual figures.

Your analogy of the Newtonian theory of gravity is interesting. If that theory had predicted the past positions of the planets accurately, but predictions of future positions became progressively less accurate, surely that would have been an indication of a problem with the theory?

At the risk of boring you. I say once again: Western countries have long been involved in projects meant to harm the developing world via droughts, floods, earth quakes, and other weather catastrophes.

According to reports on climate change, western states (especially the United States) are using equipment that discharge clouds and prevent rain-bearing clouds.

It only takes one developing country to wise-up and pursue the matter through investigation and legal channels.

e.g. Droughts in some regions spanning from Turkey and Iran to east of Asia are predicted for the next 30 years. Is this weather or weapon?

How can IPCC or anyone else predict any weather patterns, if the weather patterns are being manipulated and if the weather patterns are being manipulated is that not a crime against humanity?

p.s. The United Nations has a resolution against weather manipulation. Why would it have such a resolution if such was not occurring?

Weather control, particularly hostile weather warfare, was addressed by the "United Nations General Assembly Resolution 31/72, TIAS 9614 Convention[19] on the Prohibition of Military or Any Other Hostile Use of Environmental Modification techniques. The Convention was: Signed in Geneva May 18, 1977; Entered into force October 5, 1978; Ratification by US President December 13, 1979.

At a counter terrorism conference in 1997, United States Secretary of Defense William Cohen referred to the writings of futurist Alvin Toffler, specifically regarding concerns about "environmental terrorism" and intentionally caused natural disasters.

So what happened between 1979 and 1997 and what is still happening?

Thank you, Paul B. I hope Paul H will correct his headline and post here. If he wants to be sure, he should contact Dr. Hansen (not "Mr. Hansen"). He does take the time to answer questions.



Observations have been in the low side of the mean projections of the 1st IPCC report, and high side of the 2nd report. They're somewhat in the middle of 3rd report, but the time period since this report isn't very meaningful. Individual climate model runs that include GHG forcing often show flat or declining temperatures for a decade. Even 20-year periods (less often) can show flat temperatures, but at the very least, trying to validate models based on 10 years is very foolish.



https://www.realclimate.org/index.php/archives/2008/04/model-data-comparison-lesson-2/



Since this thread involves a Hansen study, it's worth comparing one of his early projections (which used a climate model with a climate sensitivity value of 4.2 C) with a typical contrarian model, in this case what the trend would look like if one believed Richard Lindzen.



https://www.skepticalscience.com/lindzen-illusion-2-lindzen-vs-hansen-1980s.html



We can also look at a projection from 1981. Although slightly on the conservative side, it was remarkably accurate.



https://www.skepticalscience.com/Hansen-hit-a-home-run.html

QV said;



"As I have previously attempted to point out, this is a logically flawed argument.

If the models hadn't accurately "projected" the 20th century temperatures, we wouldn't know about them. It would be possible to devise models based on random forcings, some of which would, by sheer chance, accurately "predict" past temperatures. That doesn't mean they will accurately predict future temperatures."



I think there may be some logical flaws in your own argument. The models are not based on random forcing but on the best physics and data science has. So the models claims are still valid, if they have accurately tracked temperature through the last century or more then they are more likely than not accurate enough to predict near future temperatures. As Marks links show, they have done a reasonable job for the last couple of decades.



Of course they could be wrong (in fact they will can only ever be right within a range of uncertainty) but by pure reason alone it is more likely that they will be something like, rather than not .



You cannot deny that the conclusions from models are the best information we have to base any future policies or actions on. This is like the business of risk management, uncertainty can not be used as justification for inaction, but quite the opposite.



Lazarus

https://lazarus-on.blogspot.com/

QV @ #19 and #20



I think Mark and Lazarus have probably covered most of the points here.



The point that the data since 2000 is all we have to test the most recent projections against is NOT an excuse for drawing conclusions that lack scientific validity! Furthermore, there are valid scientific reasons why global temperatures would be expected to be below projections just now.



Hopefully, by the time IPCC AR5 is prepared there will be a bit more data to add to the comparisons.



Paul

#23 - Lazarus wrote:

"I think there may be some logical flaws in your own argument. The models are not based on random forcing but on the best physics and data science has."

I didn't say they were random, I said that random models could produce apparently accurate "projections" of past temperatures, but that wouldn't mean that they would predict future temperatures accurately. I still say that since the model scenarios must have been selected on the basis that they were accurate in the past, (they presumably wouldn't have used them if they were inaccurate), they cannot be used as evidence of the accuracy of the models.



"So the models claims are still valid, if they have accurately tracked temperature through the last century or more then they are more likely than not accurate enough to predict near future temperatures. As Marks links show, they have done a reasonable job for the last couple of decades."



Actually the models didn't accurately track temperature through the last century.

I have looked back further than the 1980 starting point used on the Realclimate graph (using the A1B scenario) and those prior to 1985 showed a tendency to UNDERESTIMATE temperature based on HadCRUT3. Most of the hindcasted temperatures prior to about 1985 were lower than HadCRUT3, with a cumulative error of +0.086c (i.e. HadCRUT3 higher) by 1945, which had only fallen to +0.062c by 1985. As a result of the recent over estimations, the cumulative error has now fallen to +0.038c by 2009.

While this may appear to contradict the argument that the A1B models are biased towards warming, what it really means is that prior to about 1985 they UNDERSTATED the warming, and after 1985 they have tended to OVERSTATE the warming. Given that the retrospective "predictions" UNDERESTIMATED temperatures, it is reasonable to expect that they would continue to do so in the future, i.e. temperatures SHOULD be higher than the projections, not lower.

In 22 of the 25 years since 1985, the 3 year MA HadCRUT3 anomaly has been below the 3 year A1B MM mean prediction, and it has been below the prediction for every year since 1999, based on anomalies relative to 1980-99. Prior to 1985, in 67 of the 84 years, HadCRUT3 was above the A1B MM prediction.



"You cannot deny that the conclusions from models are the best information we have to base any future policies or actions on. This is like the business of risk management, uncertainty can not be used as justification for inaction, but quite the opposite."

I am afraid

I evidently ran out of characters again.

My last sentence should have said:



I am afraid that I DO deny it. I prefer to use ACTUAL data, rather than MODEL data. Your argument sound as if you believe that MODEL data takes precedence over ACTUAL data.

Paul Hudson



Have you looked at Judith Curry's blog? Her essays on UNCERTAINTY are well worth a read.



https://judithcurry.com/2011/03/24/reasoning-about-climate-uncertainty-draft/

It is a shame that there aren't more people like you Paul who are big enough to admit when they have got something wrong. In fact I am not surprised, you are the only forecaster I know of who can stand there on TV and admit when you have got the forecast wrong. Your standing can only be enhanced by it.

Many thanks to Paul Hudson for adding his update. Sadly, there are many other blogs where the host would not be so willing to acknowledge such a mistake (and I'm the first to admit that we all make them!). I am glad to be contributing to one which does correct errors........ on the very rare occasion that they occur!



Paul

QV you said;



"I didn't say they were random, I said that random models could produce apparently accurate "projections" of past temperatures, but that wouldn't mean that they would predict future temperatures accurately."



I know that you did not say that the current models were random but you said that models containing random forcings could track past temperatures just as well as current models that use established physics, fluid dynamics, and the best data we have etc, with what I believe was a clear insinuation that current models could not be relied on to predict current temperatures any better than random ones.



This is clearly a poor argument for the reasons I have previously given in message 23. While you may criticise the models for not being as accurate as you think they ought to be you still fail to address the issue that they will be more accurate than any other method of prediction.



I do not accept your idea that we must wait for actual data. It totally fails to address the issues of the risk management of any uncertainties.



The models, based on the best science and research we have, predict that temperatures will continue to rise within the margins of error the models outline, as the first graph here shows;

https://www.realclimate.org/index.php/archives/2011/01/2010-updates-to-model-data-comparisons/



Again I state that rationally, you cannot deny that the conclusions from models are the best information we have to base any future policies or actions on.



If you have better, more robust and subjected to the criticism of peer review research then present it.



****************



I would also like to commend Paul Hudson for his admission that in this case at least he may have over simplified the research, particularly since there seems to be little evidence that it is yet peer reviewed.



What I find noteworthy is the comment from LabMunkey who wrote that it could be the:



"apparently honest bit of science for once from the climate establishment."



I can envisage this typed with a knowing nod, but with details of Hansen's actual words emerging it clearly looks like a case of someone seeing what they already believe to be the truth without reference to the actual data or even this, apparently as yet to be peer reviewed piece.

@ Paul Hudson



Good to see that you do read the feedback and that you have the courage to admit a mistake. Well done that man



smoke me a kipper

#30. - Lazarus wrote:

"I know that you did not say that the current models were random but you said that models containing random forcings could track past temperatures just as well as current models that use established physics, fluid dynamics, and the best data we have etc, with what I believe was a clear insinuation that current models could not be relied on to predict current temperatures any better than random ones. "

Again, I have failed to explain myself as well as I could. What I meant was that SOME random models could APPEAR to track past temperatures, by sheer chance, and if specially selected from the many others which failed to do so. However, those models would be no better at predicting future temperatures than the others.

This is a bit like the proverbial "infinite number of monkeys", typing the works of Shakespeare. The fact that one monkey has by sheer chance typed half of the works of Shakespeare correctly, makes it no more likely that it would type the other half correctly than any of the other monkeys.



Comparing the "predictions" of the A2 and A1B models for past years with actual HadCRUT3 figures, there is CLEAR EVIDENCE that there have been periods in the past where the models have underestimated temperatures and periods when they have overestimated them. That clearly suggests that there are periods when negative forcings have been overestimated and periods when they have been underestimated. Personally, this does not give me much confidence in the models. Since we now appear to be in a period where they are underestimating them I therefore agree with P.H. that it still appears that temperatures are currently being overestimated by the models. I will post again when I have some figures to support the above.

30. Lazarus:



As far as I can see Hansen posted the paper as a 'draft' for comment. It has not yet been submitted for review.



Here is another interesting take on it: https://www.abc.net.au/unleashed/2722486.html

32. QuaesoVeritas wrote:



"Comparing the "predictions" of the A2 and A1B models for past years with actual HadCRUT3 figures, there is CLEAR EVIDENCE that there have been periods in the past where the models have underestimated temperatures and periods when they have overestimated them."



The IPCC doesn't make 'predictions', it just shows the range of modelled 'projections'. The fact that actual temperatures have remained within the range of projections is quite impressive. As is the fact that temperatures have continued to rise, not fall, as some had predicted. If you check the IPCC projections against the 'predictions' of many sceptics you might be more impressed by them.



For instance in September 2008 Piers Corbyn confidently claimed that the world's temperatures were falling and would continue to do so (https://climaterealists.com/index.php?id=1771%29. CO2 had nothing to do with temperatures he said. The period after this announcement was one of rapid warming, and included the warmest continuous 18 month period in the instrument temperature record (Jun 2009-Nov 2010 [NOAA]).



None of the other 'sceptical' predictions have faired any better, as far as I know. So as Lazarus says, imperfect and imprecise as they are, these models have consistently proven to have been our most reliable source of informed opinion on long-term temperature fluctuations. But for the sake of 'balance' I should advise readers that Piers is still selling his predictions... if you're interested.

Re 34:



The link to the 'Climaterealist' interview with Piers Corbyn appears to be dead. I'll quote exactly what he said here:



""CO2 has never driven, does not drive and never will drive weather or Climate. Global warming is over and it never was anything to do with CO2. CO2 is still rising but the world is now cooling and will continue to do so."



[Friday, September 5th 2008, 6:33 PM EDT]

#34. - newdwr54 wrote:

"The IPCC doesn't make 'predictions', it just shows the range of modelled 'projections'. The fact that actual temperatures have remained within the range of projections is quite impressive. As is the fact that temperatures have continued to rise, not fall, as some had predicted. If you check the IPCC projections against the 'predictions' of many sceptics you might be more impressed by them."

I put the word "predictions" in quotes because I know that to talk about predicting the past is nonsense. I am not sure that "projections" is a better term and maybe I should have used "hindcasts" to avoid possible confusion. I see no point in comparing the IPCC model projections with those of sceptics, since I am sure that the IPCC ones are better. I have no more faith in the predictions of "sceptics" than I do those of the IPCC. However, the IPCC has greater resources at it's disposal, so they should be better and they also have a much greater influence on politicians.

As I have attempted to explain, I don't think that the accuracy of "hindcasts" is of any significance, since the models must have been chosen on the basis that the "hindcasts" were reasonably accurate. Unless, that is that the models were developed entirely theoretically and were only run to produce the IPCC projections without any prior validation. To say that actual temperatures have remained within the range of projections is barely true, since they have been outside the range of the vast majority of the model projections.

But please, go on believing in the absolute accuracy of the IPCC models if you wish.

#35. - newdwr54



Clearly what Piers Corbyn is quoted as saying is absolute rubbish.

Personally I have never denied that CO2 causes warming or that warming is over.

However, my contention is that warming and the alleged effects of warming on the general climate have been exaggerated.



Isn't Piers Corbyn the one who was predicting weather and the exact dates of earthquakes based on solar flares? I always thought that was nonsense.

Has Mr Hudson wandered off-message AGAIN? It's not often Paul edits and updates his posts with apologia. Must have come from way on high... a trail back to RC?

"...go on believing in the absolute accuracy of the IPCC models if you wish."



I've already described them as 'imperfect and imprecise', but they are broadly accurate in terms of the direction of the trend and its admittedly quite broad parameters. The fact is that we remain on target within the parameters of the A1B scenario.

The science is flawed on two main counts (i) sensitivity and (ii) feedback.



The sensitivity parameter is a measure of how much extra heat the atmosphere will retain for a given rise in CO2. The IPCC has hitherto stated "between 2 and 2.8 W/m2" with clouds doing the exact opposite, cooling us between (hah!) 0.3 and 1.8 W/m2. And we base major public policy on these wild stabs at quantifying the "problem"!



As for feedback, is it POSITIVE feedback (the hotter we get the faster we'll get hotter) or NEGATIVE feedback (the hotter we get the greater the heat losses and so we'll level off)? Planet Earth's 4.5 billion year history suggests the stability of negative feedback rather than the precarious teetering balance of positive - and Al Gore's "tipping point" expression.



This global warming nonsense is just the latest in a long tradition of end-is-nigh apocalypse stories. Folks, let's laugh at this foolishness until our politicians brush off the bent scientists promoting this hoax. Global Warming, Global Schwarming.

Lateintheday.



I was only saying lets have a court enquiry in a tongue in cheek way. What we really need it is real science, not this stuff based on false evidence appearing real.

@ Paul Hudson,

Nice one for correcting what could have been a potentially misleading post- nothing wrong with making a mistake if you correct it once spotted. You've done nothing but improve your credibility. Shame some climate scientist i could mention don't take the same tact....



@ (the other) Paul, no skeptics deny that climate science is complex... that's one of 'our' main reasons for not agreeing with the conclusions. As for climate science not reflecting uncertainty- I too suggest you go read Judith Curry's blog post on the issue- it seems you're stuck in the RealClimate PR world and not the real one the rest of us inhabit.

Paul what has happened to the UAH global satellite temperatures for April?

Re 40.At 22:14 22nd May 2011, Brent Hargreaves wrote:

"As for feedback, is it POSITIVE feedback (the hotter we get the faster we'll get hotter) or NEGATIVE feedback (the hotter we get the greater the heat losses and so we'll level off)? Planet Earth's 4.5 billion year history suggests the stability of negative feedback rather than the precarious teetering balance of positive - and Al Gore's "tipping point" expression."



James Hansen, the author of the paper discussed in this post, actually refers to earth's history as the primary evidence for positive feedback in climate. In the paper he suggests model aerosol forcing is too low and response time must be too high. He doesn't think that model sensitivity is too high (another solution) because he thinks earths history validates that finding.



In my opinion temperature changes in Earth's history are too large to be compatible with negative feedback, unless there is some massive and unknown forcing operating throughout time on many timescales, and I find such a massive forcing being so far undetected as improbable, or at least I find it much more probable that climate sensitivity is high.



Additionally in my opinion there is another reason why positive feedback more easily fits earth's climate history. Earth's temperature history does not fit any single forcing that well. If there was an undetected massive forcing it would dominate climate and so global temperature should correlate well with that forcing (making it more obvious and easier to detect). On the otherhand positive feedback would amplify all the small known forcings and so global temperature wouldn't be expected to correlate with any particular forcing over time, which I think fits well with earth's temperature history.

I have split this post into two parts, in case it is truncated.

PART 1:

Further analysis of the A1B scenario model predictions has revealed that current temperatures are below 18 of the 21 (86%) model projections which make up

the scenario, a similar situation to that which exists in the case of the A2 scenario.



However, looking at the detail of the individual models, has caused me to slightly adjust my stance on this matter. My opinion now is not that all of the IPCC models have a warming bias, but that some of the models have a warming bias.



Comparing actual temperatures with the Multi Model Mean figure does suggest that overall, the scenario is overestimating temperatures, but clearly not all of the models are overestimating them and while some models are overestimating them more than others, some, although not many, are even underestimating them.

Of course, in retrospect, this is obvious, although I feel less ashamed because I don't recall that anyone else pointed it out.



Clearly some models are more "guilty" than others in that they are responsible for the most of the overestimation of the temperatures, so I have done some more work on individual models, in order to identify those which are the worst offenders.



It turns out that the worst offender in both the short-term and long-term, is the miroc3_2_hires model, which predicts a 3 year MA anomaly of +0.79c by 2009 (2008-2010), which is 0.13c above the next highest model and 0.53c above the actual 3 year MA anomaly based on HadCRUT3. It predicts an anomaly of +1.11c by 2020, which is 0.07c above the next highest and +4.43c by 2098, which is 0.9c above the next highest model.



Unfortunately the use of a base period of 1980-99 makes it difficult to put these anomalies in context, in relation to the current HadCRUT3 anomaly, but I calculate that you have to add 1.57c to the 1980-99 anomalies to make them equivalent to the 1961-90 anomaly. I think it is interesting that this model doesn't look unusual during the 20th century, and only starts to show "extreme behaviour around the year 2000.

PART2:



The 5 "worst" models, based on their positive variance from the actual 2008-10 mean HadCRUT3 anomaly are as follows:



miroc3_2_hires (+0.53)

ncar_ccsm3_0 (+0.406c)

ipsl_cm4 (+0.33c)

cccma_cgcm3_1_t63 (+0.32c)

inmcm3_0 (+0.28c)



Since the above models have performed worst against actual anomalies so far, it would seem logical to exclude them from future temperature predictions.

If they were excluded from the A1B scenario, it would reduce the Multi-Model Mean prediction for 2099 from +2.82c to +2.70c. Remember you have to add 1.57c

to this to get the equivalent 1961-90 anomaly.



The reason that the exclusion of the above from the MMM doesn't reduce the long-term anomaly prediction very much is that while the above models account for a large part of the variance of predicted from actual temperatures by 2009, they don't necessarily produce the highest predicted anomalies by 2099. The 5 models which show the highest predicted anomalies in the A1B scenario by 2098 are as follows:



miroc3_2_hires (+4.43c)

ukmo_hadgem1 (+3.54c)

mpi_echam5 (+3.44c)

miroc3_2_midres (+3.40c)

ipsl_cm4 (+3.24c)



While it may seem logical to exclude the above from the scenario, assuming you wish to reduce the long-term warming bias, since there is less evidence that 3 of them are currently overstating the warming, there is probably no case for doing so.



The overall effect of removing the first 5 models from the scenario varies according to the timing of the prediction. In fact, removing the 5 from the scenario would increase estimated anomalies between 1900 and about 1995 and reduce them between 1996 and 2099, with the largest reductions occurring between 1996 and 2036.

P.S.

I should have added that while excluding the "worst" 5 models from the scenario would obviously bring the MMM projection nearer the current actual anomaly, it would still leave it about 0.11c above it, based on the 2008-2010 3 year averages.

45 & 46. QuaesoVeritas:



It is my understanding that AR5 will be based on fully up-dated models, and that there will be many more than we currently have.



BTW, are there any models that accurately trace the actual temperature fluctuations?

#48 - newdwr54 wrote:

"It is my understanding that AR5 will be based on fully up-dated models, and that there will be many more than we currently have."

I wonder what "up-dated" means, i.e. will they be re-aligned to actual temperatures?

I am not sure if more models is necessarily an improvement.



"BTW, are there any models that accurately trace the actual temperature fluctuations?"

Not that I can see, although it would involve a lot of comparative work, to identify which were the most accurate over individual years.

On a purely visual impression, mpi_echam5 looks close and that happens to be the third highest by 1998. However, it does go up fairly rapidly between now and 2015, so that should be a test.

Hopefully the IPCC or the originators of the models will be doing some performance measurement.

Sorry I meant that mpi_echam5 was the third highest by 2098.

49. QuaesoVeritas wrote:



"I wonder what "up-dated" means, i.e. will they be re-aligned to actual temperatures?"



Of course. If some of the older models are shown to be demonstrably wrong in their projections then they will obviously be amended. As I said before, these were never meant to be 'predictions'. They are modelled 'projections' based on the best evidence available to the respective teams at the time. They all used different methods, which was sort of the point; it's an ongoing evaluation process.



As new and (hopefully) better information and techniques come in the models will naturally be revised. Isn't that the way science ought to work?



The models have been too high in most cases. If it was me, I'd look closely at how the best models handled sensitivity to reduced solar input and negative ocean circulation patterns, etc. It is possible that the most accurate models put greater negative weighting on these factors. Reduced solar was always likely to be a factor between 2000 and 2011 given the known 11-year solar cycle for instance.



I would predict that the newer models should be more accurate on average.

#51 - newdwr54 wrote:

"Of course. If some of the older models are shown to be demonstrably wrong in their projections then they will obviously be amended. As I said before, these were never meant to be 'predictions'."

That's not how it came across in the media.

"As new and (hopefully) better information and techniques come in the models will naturally be revised. Isn't that the way science ought to work?"

Yes, but is it happening quickly enough? Meanwhile everyone is using dubious figures.



"The models have been too high in most cases."

That sounds like a change in attitude on your behalf?

I thought it was your contention that most of the models were accurate?



"If it was me, I'd look closely at how the best models handled sensitivity to reduced solar input and negative ocean circulation patterns, etc. It is possible that the most accurate models put greater negative weighting on these factors. Reduced solar was always likely to be a factor between 2000 and 2011 given the known 11-year solar cycle for instance."

The problem is that I don't think that the individual models are consistent. Sometimes the seem to overestimate temperature and sometime overstate it, although I haven't gone into individual models on that level of detail.



"I would predict that the newer models should be more accurate on average."

I would hope so!

James Hansen is an astrophysicist not a climate scientist.



IPCC 'science' claims that the residence time of CO2 in the atmosphere is 200 years. All recent research put residence time at 5-7 years. Put the correct time into their models means NO temperature change due to CO2 changes. I have tried this and it works well. So no problems with rising CO2 levels then.



This also relies on the belief in the theory of the greenhouse effect. The internet will produce peer reviewed papers arguing that this effect is not valid due to violations of the laws of thermodynamics.



The IPCC has also been completely wrong in its claims about the Amazon floods, Himalayan Glacier melt, in fact so many claims have failed as to be too many to list here. In fact the two mentioned were claimed to be from peer reviewed papers and turned out to be nothing of the sort. The Himalayan claim was actually from a WWF claim again not from any true research.



That railway engineer, PhD in Economics, is still in charge of the IPCC as well. Another non climate scientist.

!!! CORRECTION !!!

Re: #45 & #46

Before anyone points it out, the adjustment factor to convert the 1980-99 anomalies to 1961-90 anomalies, should be +0.157c, not +1.57c.

Re 53.At 12:54 23rd May 2011, John Marshall wrote:



"James Hansen is an astrophysicist not a climate scientist."



Not that it really matters, but he's a climate scientist as he has done so much work on the subject of climate.



"IPCC 'science' claims that the residence time of CO2 in the atmosphere is 200 years. All recent research put residence time at 5-7 years."



Average CO2 molecule lifetime is 5-7 years, but that's not residence time. Residence time is how long it takes for CO2 levels to fall back to where they started after a given increase. That's not the same as lifetime.



"This also relies on the belief in the theory of the greenhouse effect. The internet will produce peer reviewed papers arguing that this effect is not valid due to violations of the laws of thermodynamics."



The greenhouse effect is a fact. I don't say that about many things on this subject, but that one truely is a fact. Arguments to the contrary, especially claims it violates thermodynamics, are psuedoscience.



"The IPCC has also been completely wrong in its claims about the Amazon floods, Himalayan Glacier melt, in fact so many claims have failed as to be too many to list here."



It is not logical to dismiss the theory based on two (or even 10) mistakes the IPCC has made reporting specific effects. Given you question the greenhouse effect and made an error over CO2 residence times I hardly think your primary problem accepting the science is how the IPCC report it anyway.



"That railway engineer, PhD in Economics, is still in charge of the IPCC as well. Another non climate scientist."



That's a very odd argument given your opinion of climate scientists. I would have thought you would be happier with someone who wasn't in that circle at the helm. But then perhaps your objective is to never be satisfied with the IPCC unless it starts claiming the greenhouse effect is a myth and starts confusing residence times and atmospheric lifetimes.



The last head of the IPCC was a climate scientist. A british one too. He was ousted under pressure of the US government at the time and it was they who voted for our railway engineer + economics professor to be the new head. It looked very much like this was an attempt to get someone more industry friendly at the helm as the previous climate scientist head was awkwardly and loudly backing a certain climate theory...



Funnily enough I can't remember skeptics at the time complaining this was a bad move because the IPCC head should be a climat

QV @ #45 and 46



Based on these posts, I think you and I are fairly close to agreement.



Having said that, I think the term "guilty" to describe errant models is perhaps a bit unfair! As has been pointed out already, these models are based on best scientific understanding and are not tuned to temperature. So we need to be clear that they have not been "fixed" in such a way that they overstate the warming



It's also worth pointing out that although each model will have a slightly different mean trajectory, the different runs for each model vary widely in their outcome, so any differences between the models (at least in the short term) are very unlikely to be statistically significant.



I suspect part of the problem here is that when people look at these projections they presume that the temperature anomalies should invariably fall on or very close to the prominent mean line. Yet there is no scientific justification for this - given the way the models are devised, there is no reason at all to presume that those with mean trajectories closest to the centre of the range are any more likely to be right than those at the top or the bottom. The whole purpose of the uncertainty limits is to make it clear that the real rate of temperature rise could lie ANYWHERE within the range. So it is entirely conceivable and within the bounds of what the IPCC projected that the more conservative models will ultimately prove more accurate.



I think it's also worth pointing out that the IPCC are merely reporting what the scientific community have found, so if most of the models overstate the warming, that isn't the IPCC's fault!



Paul

There was nothing in the IPCC about Amazon floods...there was a 'non paper' about amazon droughts and that was shown to be true.



Even Monckton, Spencer, Litzen et al will say that the greenhouse effect is a real and provable theory.

I think it was a bit strange to close comments on the cracks appearing in the political concensus on carbon reduction before it became apparent that Cameron (presumably for political rather than scientific reasons) had opted to try to shore up Huhne.



I think the deal to fob off Osborne and the rest was that there would be a possible opt out in 2014 which would allow us to row back from the chasm before too much damage had been done. This could turn out to be over-optimistic.



Huhne's plans involve signing up to committments to the wind turbine producers that the flow of cash from the climate change levy and the feed in charges will persist through to 2035. It also involves feather bedding for EDF, EON et al to guarantee that the electricity from their nuclear stations will have to be taken and will have a guaranteed floor price which will keep it dear.



If it all appears by 2014 to be a ghastly mistake, UK plc will be obliged by binding contracts to live with these high prices for at least another 20 years.

I'm no more qualified to assess a climate science paper than Paul Hudson, weather presenter, but it seems abundantly clear that Mr Hudson has once again confused himself and his readers by drawing a conclusion not supported by what he has read.



Hansen et al make it abundantly clear that the concern is that aerosol forcing has been understated:



> If the negative aerosol forcing is understated by as much as 0.7 W/m2, it means that aerosols have been counteracting half or more of the GHG forcing.



> ...concern about health effects of particulate air pollution is likely to lead to eventual reduction of human-made aerosols. Thereupon the Faustian payment will come due.



In other words, the IPCC has *underestimated* the impact of aerosols and if we stop pumping this pollution in to the atmosphere, the effect will be *increased* warming.



Or put another way: we would need to pump more and more pollution in to the atmosphere to counteract the ever-increasing CO2 levels.



Mr Hudson would do well to stick to smiling and reading weather scripts and leave climate science to those who are qualified and capable, because this is yet another example of him dangerously misleading people.



P.S. Dr Joe Romm provides a scientifically literate analysis: https://climateprogress.org/2011/04/20/hansen-sea-level-rise-faustian-aerosol-bargain/



P.P.S. Mr Hudson, James Hansen has a doctorate. That means you address him as 'Dr', not 'Mr'.

#56. - Paul Briscoe wrote:

"I think it's also worth pointing out that the IPCC are merely reporting what the scientific community have found, so if most of the models overstate the warming, that isn't the IPCC's fault!"

I have to disagree with you on that.

The IPCC has a "climate change" agenda and as far as I know, only publishes "alarmist" reports which supports that agenda. Otherwise, it only

puts one side of the case, and I suspect would be more likely to publish a "dubious" document (e.g. Himalyan Glaciers), if it generally supported "climate change". We may be close on the temperature issue, but not I think on the overall implications of temperature rise.

QV @ #60



I think you are being unrealistic there, QV.



Are you saying that the IPCC are ignoring other models which show a very different picture? If not, the IPCC surely has a DUTY to present the results. It is the individual scientists rather than the IPCC who are answerable for the details of their models. It is also not the IPCC's fault if sceptic scientists cannot come up with convincing evidence in support of their views!



People keep coming back to "Himalayagate" and "Amazongate", but they seem to forget that these were not part of WGI - The Physical Science Basis. Much of the literature used in other parts of the report used literature that was not peer reviewed......... and that was where the problems arose.



I don't think your criticisms are justified in relation to the physical science evidence. If you read IPCC AR4 WGI you will note that one of the acknowledged uncertainties relates to the regional effects of AGW.



Paul

BlueRock: "P.P.S. Mr Hudson, James Hansen has a doctorate. That means you address him as 'Dr', not 'Mr'."



Mann has a doctorate (and came by it rather suddenly), but he still practices and defends pseudoscience rather than real science. Logically fallacious arguments from authority, particularly nasty and derisive ones like yours towards Paul Hudson, carry little sway. They have none at all with discerning observers of climate science. We have seen too much, too many breaches of the scientific method and too much political advocacy generally from the likes of Hansen and others in the subject.

Simon H @ #62



I don't condone attacks on our host and perhaps Bluerock's tone was a little patronising, but he has made an important point - Paul Hudson needs to be very careful to get his facts right BEFORE posting.



Meanwhile, your own comments here, together with your previous ill-considered contribution at #38 indicate that you are still wedded to the "World According to Climateaudit" rather than any truly objective assessment of the facts!



Paul

#59. BlueRock wrote:

"I'm no more qualified to assess a climate science paper than Paul Hudson, weather presenter, but it seems abundantly clear that Mr Hudson has once again confused himself and his readers by drawing a conclusion not supported by what he has read."

According to the BBC Look North website, Paul Hudson read geophysics and planetary physics at Newcastle University, so I will leave it to you to assess whether you are more qualified than he is:

https://www.bbc.co.uk/england/looknorthyorkslincs/paul.shtml



Hansen et al make it abundantly clear that the concern is that aerosol forcing has been understated:



"In other words, the IPCC has *underestimated* the impact of aerosols and if we stop pumping this pollution in to the atmosphere, the effect will be *increased* warming.

Or put another way: we would need to pump more and more pollution in to the atmosphere to counteract the ever-increasing CO2 levels."

Or to put it yet another way, if the level of pollution remains the same, the models may continue to be overestimated. Somehow I don't think that we will need to deliberately pump more pollution into the atmosphere, the way things are.

Actually said almost exactly what you say, in his original blog:

"And so if the air is cleaned up and aerosols decrease in concentration in years to come, global temperatures could make up for lost time and rise sharply in response. "

#61. - Paul Briscoe wrote:

"I think you are being unrealistic there, QV."

So how many papers/articles/reports, have the IPCC , which

contradict AGW theory? Isn't there an underlying assumption that

"climate change" is happening? I think the answer is in the name - IPCC.

A less biased name would be Intergovernmental Panel on Climate Variability, or Climate Study.

Sorry, correct post:



#61. - Paul Briscoe wrote:

"I think you are being unrealistic there, QV."

So how many papers/articles/reports, have the IPCC used , which

contradict AGW theory? Isn't there an underlying assumption that

"climate change" is happening? I think the answer is in the name - IPCC.

A less biased name would be Intergovernmental Panel on Climate Variability, or Climate Study.

Paul Hudson writes:



"In particular in my article I suggest that aerosols are underestimated by IPCC models, which would lead to an over estimation of temperature predictions going forward, which remains valid."



This is still backwards. Contrarians (Lindzen being one glaring example) often try to argue for low climate sensitivity via instrumental record analysis by taking liberties with uncertainty around sulfate aerosol's impact, arguing in effect that the forcing is zero, meaning that there "should have been" more warming than observed. A lower climate sensitivty, of course, means lower projections going forward.



https://www.skepticalscience.com/print.php?n=706



Conversely, if negative forcing from aerosols is much stronger than models show, then it would require a larger positive forcing from somewhere else (i.e. GHGs) to explain the observed trends, implying higher climate sensitivity. This alone doesn't mean more warming is in the cards, as climate sensitivity is derived from paleo observations and observations of feedbacks during ENSO and volcanic events, and they tend to converge around 3 C for a doubling of CO2.



Furthermore, since sulfur emissions have reached their peak in the mid-70's, have levelled off since then, and are expected to decline further over the course of the 21st century, then it follows that further reduction of a stronger-than-modeled negative forcing would result in more warming.



https://tamino.files.wordpress.com/2010/08/emission.jpg

And again, why not ask Dr. Hansen or one of his co-authors if your interpretation of their research is correct? Hansen is a busy man, but is often responsive to honest inquiry.



Although there aren't that many, a few other journalists do this. While I'm not much of a fan of Andy Revkin's blog, he will take the time to contact scientists to get a better understanding of their research.

QV @ #64



In fact, the scientific literature tends to support the view that aerosol levels are not increasing. On the contrary, the work of Pinker et al reports "global brightening" since 1990, whilst GISS' own data shows aerosol levels stable since 1990 - see Figure 2 of this article:



https://www.skepticalscience.com/Could-global-brightening-be-causing-global-warming.html



So I think the point James Hansen was probably making was that models have historically underestimated aerosol forcing. If aerosol levels are no longer rising, they are already exerting their maximum cooling effect, so they are not going to counteract any further additions of greenhouse gases. On this basis, one might expect the warming process to accelerate in the near future.



Paul

QV @ #65 and #66



It is scientists who write the WGI reports and I'm quite sure they were not responsible for the choice of the IPCC's name!



The WGI report DOES make reference to scientific papers which disagree with the consensus. Where it does their findings are appropriately weighed up against those of others. In truth, though, the number of papers contradicting the consensus is small!



Paul

52. QuaesoVeritas:



In response to 51...."The models have been too high in most cases."



QuaesoVeritas wrote:



"That sounds like a change in attitude on your behalf?"



I hope not. I hope I have been consistent in accepting that the IPCC projections have been on average higher than the actual temperatures, though well within the range of models used. In fact NASA's 2010 average temperature was spot on the average in the modelled range of projections for that year.

@ Paul,

The IPCC was set up to find and publish evidence to support the theory that climate change is man-made. It was in the original charter, it's original mission statement as is readily available online (despite it since being deleted and 're-branded').

It is of course entirely possible that the scientists working for and submitting to the IPCC are entirely impartial and honest (in fact i'd submit that contrary to most vocal sceptical beliefs that over 90% of the scientists involved are such), however it is the 'guiding hand' at play here that is the issue.



The IPCC is undeniably a politically motivated organisation- it's own initial mission statment confirms this. There is contradictory evidence available that stands up against the IPCC view- yet it IS downplayed and marginalised (your argument that the quantity rather than quality of the research is more important is a poor and rather tired tactic of yours).



Further, given the LARGE and significant number of 'expert' opinions/conclusions to which the IPCC 'science' is based on and that these are largely made by the 'core' team/beurocrats means that the evidence of politicisation that is rife (and has been exposed numerous times) in the IPCC becomes far more pertinent.



i firmly believe that 90% of the contributors to the IPCC documents are open, honest and hard-working scientists. I cannot and will not say the same about those that decide the tone, structure and sumamries for the reports- all evidence points to them being highly duplicitous at best.

@ 71



I think the issue stems from the shifting of the 'tipping point'.



The models do track at the lower end of their predictions reasonably well (for some)- yet it is the ramping phase (which so far, has not occured) that is the issue.



I wonder- how many 'ramp' phases have been predicted and since missed? MAy be worth a look that- i'l lget back to you.

#71. - newdwr54 wrote:

"I hope not. I hope I have been consistent in accepting that the IPCC projections have been on average higher than the actual temperatures, though well within the range of models used. In fact NASA's 2010 average temperature was spot on the average in the modelled range of projections for that year."

I will have to take your word for that, but I wouldn't be surprised, since 2010 was an exceptionally warm year, in comparison to the last decade.

However, are you sure that the NASA figure has been adjusted to 1980-99, instead of the normal base period of 1951-80?

The multiplicity of base periods and the need adjust them to the same period as the projections is an irritation. Thinking about it, I am sure that at the time of Copenhagen, figures were being quoted relative to "pre-industrial" times, which I believe was defined as 1861-1900, which of course, made them appear higher.

I can't help thinking that this plethora of base periods might be designed to cause confusion. Whenever someone quotes a rise in temperature, the first question to ask is, "relative to what period?). I suspect that some campaigners wouldn't know the answer to that question. Of course, the same applies to carbon reduction targets.

LabMunkey (various).



It strikes me that your posts become more and more arbitrary over time……. and you’ve even started contradicting yourself.



First of all, I would refer you to the end of Lazarus' post @ #30 regarding your wholly arbitrary comment which started this discussion thread. In the light of this it was somewhat rich for you to be lecturing me regarding the supposed "PR" of sites which accurately reflect the science but don't fit well with your own preconceptions.



Now you effectively accuse the leaders of the IPCC of being "duplicitous" - an accusation for which you have no real evidence and which is tantamount to slander. I have acknowledged many times that the IPCC is far from perfect, which would be true for ANY intergovernmental panel operating under the auspices of the UN…… but to brand them as duplicitous?!



What you apparently fail to grasp is that the overwhelming majority of people who really know what they’re talking about (ie. not myself or you or the blogs you rely on) ARE convinced that AGW represents a serious threat. Many scientists even believe that the IPCC is being too CONSERVATIVE. I have certainly seen nothing in the findings/conclusions of WGI (which I have concentrated on as a scientist) to suggest that the science has been presented in anything other than a professional and accurate manner.



"It is of course entirely possible that the scientists working for and submitting to the IPCC are entirely impartial and honest (in fact i'd submit that contrary to most vocal sceptical beliefs that over 90% of the scientists involved are such)…."



And:



"i firmly believe that 90% of the contributors to the IPCC documents are open, honest and hard-working scientists."



These statements completely contradict your opening remark at post #1 - you need to decide what you really believe!



"There is contradictory evidence available that stands up against the IPCC view- yet it IS downplayed and marginalised (your argument that the quantity rather than quality of the research is more important is a poor and rather tired tactic of yours)."



No LabMunkey! There is not only very little peer-reviewed literature which contradicts the IPCC position, but most that does is of a very poor quality……. or just plain wrong. The scientists ARE professional and they DON’T simply sweep contradictory evidence under the carpet. The real problem here is that you lack the objectivity to spot the difference between good science and bad!

LabMunkey



The last couple of lines of my post were lost. The final point I was going to make is that your posts tend to be heavy on assertions and very light on actual evidence.



In a previous post you mentioned Judith Curry's blog. In fact, I've visited Judith Curry's blog a number of times. Her attempts to engage critics of climate science are laudable, but most people within the scientific community appear to feel that she is being naive. In recent months, Dr. Curry appears to have been making an increasing number of unsubstantiated and inaccurate claims........ and it isn't simply the people at Realclimate who are critical of her:



https://ourchangingclimate.wordpress.com/2010/11/05/judith-curry-building-bridges-burning-bridges/



https://julesandjames.blogspot.com/2010/11/wheres-beef-curry.html



https://initforthegold.blogspot.com/2010/10/judith-curry-born-beyond-shark.html



Of course, Judith Curry's comments regarding uncertainty will be music to the ears of those whose chief weapon is doubt, but there appear to be few genuine experts in this field of science that agree with her.



Finally, here's a contribution by Gavin Schmidt to a blog discussion where he explains the errors in some of Curry's reasoning with regard to uncertainty in the models:



https://www.collide-a-scape.com/2010/08/03/the-curry-agonistes/



Personally, I can see no problem with the way the IPCC deal with uncertainty from the point of view of scientific reporting. I think the real problem is that most people don't fully understand either the science or the significance of what is being said. There is therefore an argument for having a separate non-technical report to communicate the science to the public.



Paul

I don't know why everyone is so roused by what Hansen may or may not have said or meant. Hansen has made too many wild statements (about concentration camp guards and so on) and has nailed his colours far too firmly to a warmist mast for anyone to take him too seriously as a scientist and to take too much account of anything he may say.



What is happening on the ground in actual science is much more interesting. Evidence to support Svensmark's ideas of how cosmic rays affect clouds for example seems now to be coming in fast. With the full results of the "cloud" experiments still pending it seems likely that this support will increase.



Even Roy Spencer has become a aupporterand using the Laken et al results is now trying to make quantitative estimates of the size of the cosmic effects. He suggests that solar forcing taking these effects into account is probably 3-4 times larger than the IPCC allowed for using solar irradiation on its own.



This kind of evidence strengthens the now rather widespread view that the IPCC estimate of climate sensitivity is way too high and means that estimartes of the portion of 20th century warming that can be attributed to AGW can probably be substantially reduced.



I suspect these kind of influences will turn out to be much more important than the largely unmeasured effects of anthropogenic aerosols being discussed by Hansen.

I work with a number of copywriters. They can all convey different messages from the same data sources depending on their brief. This I think, is what Labmunkey and others find so distasteful. The thoughtful conclusions of individual, hard working scientists can be manipulated very easily by those who hold the editors seat. Indeed, even those who participate in the peer review system as reviewers hold significant influence.



The consensus view of senior climate scientists is not unlike a self fulfilling prophecy. The few who speak openly are rounded upon by the pack. Judith Curry is now an outcast. Similarly, I read a journal interview piece with Prof Mueller (BEST) which attracted the most vehement, vitriolic response from Joe Romm and others. Mueller is fast becoming enemy number one and to date, he hasn't really said anything that contentious. From the look of it, he is been warned to stay on message.



None of the above is evidence against AGW - I realise that. But it does not put supposedly good science in a favourable light either. There are many long established, hard fought reputations at stake in climate science and I don't expect anybody, from either side, to fight fair anymore. Anybody who tries, will lose the advocacy war.

lateintheday @ #78



The conclusions of IPCC AR4 WGI (ie. the scientific basis) are pretty unambiguous. It is simply untrue to suggest that the report overstates the evidence in support of AGW or the likely outcomes. I think the real problem here is that many people have problems grasping the probabilisitic approach used in science of this type. The same problem confronts epidemiologists too.



Add to the above the fact that the media do not always present science as well as they could.......... and the fact that many blogs misrepresent the science.......... and the fact that the IPCC itself probably doesn't make enough effort to communicate the science in an accessible way.......... and it becomes clear why people such as yourself would draw the conclusion you have.



Sadly, unlike policy makers, the public don't have scientific advisers to help them assess the report. So, as I said above, I think there is a strong argument for the IPCC producing a more "user friendly" report for public consumption.



With regard to Judith Curry, the problem is not that she is questioning the consensus. The problem is that much of what she is saying is just plain wrong. As for Prof. Muller, the most vitriolic attacks on him have actually come from those at WUWT, who had hoped he would confirm their criticisms of the temperature record - in fact he has done the opposite!



Paul

One more thing, for all of James Hansen's remarkable intellect he has proven himself at heart, a full blown 'green' - nothing wrong with that in principle. But is he better suited to oversee research/funding in this field because of his concerns over the environment? Or perhaps he is inevitably weakened by his prejudice - too close to the subject to be impartial?

If it's a case of the green leading the green, there may yet be some unforseen consequences of the push to limit CO2 emissions. The 'carbon tax' that we all pay now through our electricity bills etc is making power more expensive to the consumer. These artificially high prices are set to increase substantially over the next few years which by all accounts, makes known, but previously untapped natural energy resources economically viable.

With the best will in the world, history tells us that if they can make a profit out of it, they will dig it, drill it and burn it.

Not the sort of legacy Hansen would hope for, but more than likely nevertheless.

@ Paul.



Heh.



-Ok- re your 75 and lazari's point in #30 my #1 was a referral to the admission that overestimation may be occurring. I'm not interested in whether the overestimation is large or piddylingly small- it is the admission that the overestimation could be there that is interesting. It’s a step back from the entrenched attitude that the ‘core’ scientists portrayed, quite openly, when analysing the data and the theory.



The very fact that he seems to question parts of ‘his’ field (as it were) tells me that this could be worth looking into as it indicates an objectivity that has previously been lacking- I was FULLY aware that it hadn’t been peer-reviewed, hence me not going into any significant detail on the matter and if you and lazarus actually read my post again without “someone seeing what they already believe to be the truth without reference to the actual” post you may see where you went wrong here.



Further on this point- I disagree with Paul (Hudsons) assertion that the underestimation cancels out the overestimation- things are not that neat, it could have a net positive OR negative effect, but to state that the errors they only just identified neatly cancelled each other out is… suspect, to say the least.



-“Now you effectively accuse the leaders of the IPCC of being "duplicitous" - an accusation for which you have no real evidence and which is tantamount to slander”



There’s not effectively about it, I’m out and out calling them duplicitous. I need point no further than the mess over the Himalayan issue where Pirachi deliberately mislead people prior to Copenhagen by openly attacking the scientist who deigned to question him. If you need the evidence to support this (such as proof he knew of the issue prior to Copenhagen) I suggest you go visit climate audit.



-You then descend into the typical appeal to authority line you rely on so much. I fully admit that I am not 100% versed in all the intricacies surrounding the cAGW theory, however my issues revolve around procedure, data manipulation and the conclusions drawn from them- to which I am eminently qualified to comment on- more so that the core team as I ACTUALLY have substantial QA training. To put it another way, I’ve never lost data in my (scientific) life and do not use my work email to slander ‘opponents’ and suggest potentially prosecutable actions.



-My apparent contradictory statements are nothing of the sort- again you are

PB @79

yes, Muller got a 'right kicking' at WUWT when his report to congress showed no early signs of problems with the existing temp records. Mostly undeserved attacks I thought.



Watts was rightly annoyed that again, some of his work had been used before he himself had opportunity to present it publicly. Like Curry, Muller has no friends among extremists on either side. I think QV has suggested that recent adjustments to various temp data sets brings them closer in line with each other (sorry if wrong) with the exception of UAH. If this is the case, one might suggest that it could be seen as very 'convenient'. Dr Spencer's temp record could be questioned as an outlier and Muller's BEST effort would be judged by how close it was to the 'established (ment) record'.



Watts/Pielke's new paper seems to been let off the hook somewhat. I've not seen it torn apart anywhere yet. As I understand it, the study shows that although the generally accepted temp data and trend in USA is unaffected, this is as much by luck than good judgement - with a fortuitous 'canceling out' of errors. The paper does however, purport to more accurately define the error margins in current temp recording. I wondered if this would have any knock on effects for earlier work. In particular, if the current measured temps have wider uncertainty bands, then presumably that will broaden the uncertainty in the historical reconstructions? Perhaps significantly.

#82 - lateintheday wrote:

"I think QV has suggested that recent adjustments to various temp data sets brings them closer in line with each other (sorry if wrong) with the exception of UAH. "

Not entirely sure what you are referring to. I have said than when you adjust the various datasets to the same base period, they are all very similar. Maybe that is what you are thinking of. I don't think that any "adjustments" I am aware of have made much difference, although I may not be aware of all of the adjustments, only those I have noticed.

Which reminds me, I have never got to the bottom of the recent adjustments to the NCDC/NOAA anomalies!

Bandythebane @ #77



"This kind of evidence strengthens the now rather widespread view that the IPCC estimate of climate sensitivity is way too high and means that estimartes of the portion of 20th century warming that can be attributed to AGW can probably be substantially reduced."



There is one major problem with all of these arguments - solar activity has been going in the wrong direction for them to explain recent warming. If anything, the processes you describe, if proven, would mean that forcing due to greenhouse gases is even greater than the scientists are suggesting.



Paul

@Paul Hudson



Paul,



I think it's very important to understand that Hansen's research is not peer reviewed and is not published in any journal, which means it will probably feature prominently in AR5



/Mango



I don't deny climate change, I know climate changes

lateintheday,



From what I observe, Watts gets annoyed every time the wind blows. He's somewhat of a hothead.



The paper he co-authored isn't getting much heat because it says pretty much the same thing as prior analysis using similar methods. It in fact comes to the same core conclusions as previous work that Watts trashed.



https://www.skepticalscience.com/On-the-reliability-of-the-US-Surface-Temperature-Record.html



Note also that his work diverges sharply from the claims he routinely makes on his blog, which is directed towards those with a strong anti-science bent. Publishing peer-reviewed work requires a more robust analysis. While "skeptics" can always look to cheat the peer review system by seeking out lax reviewers, with Menne et al. already published and available as a reference point, it would have been difficult for Watts to publish anything supporting his previous ideology-driven conclusions.



https://scienceblogs.com/deltoid/2011/05/anthony_watts_contradicted_by.php

LabMunkey @ #81



I'm not sure how you can dress up:



"Huh, an (at first pass) apparently honest bit of science FOR ONCE from the climate establishment." (my emphasis)



and:



"i firmly believe that 90% of the contributors to the IPCC documents are open, honest and hard-working scientists."



as anything other than contradictory statements.



"The very fact that he seems to question parts of ‘his’ field (as it were) tells me that this could be worth looking into as it indicates an objectivity that has previously been lacking- I was FULLY aware that it hadn’t been peer-reviewed, hence me not going into any significant detail on the matter and if you and lazarus actually read my post again without “someone seeing what they already believe to be the truth without reference to the actual” post you may see where you went wrong here."



You only need to go back to the link I posted to Gavin Schmidt's comments to see that in reality scientists have long acknowledged the uncertainties over aerosol forcing. I have also mentioned previous peer-reviewed papers which have found the same thing. So this is no startling admission of a past lack of objectivity - the problem is that the blogs you follow studiously avoid drawing attention to the acknowledgements of uncertainty by scientists - but they have been there all along if you had only been objective enough to look.



"Further on this point- I disagree with Paul (Hudsons) assertion that the underestimation cancels out the overestimation- things are not that neat, it could have a net positive OR negative effect, but to state that the errors they only just identified neatly cancelled each other out is… suspect, to say the least."



Gavin Schmidt's comments from the link above are very relevant to this. He points out that aerosol forcing is "included in the aggregate". This means that if aerosol forcing has been underestimated then it follows that climate sensitivity has been underestimated. In fact, this ties in closely with Hansen's comments here as his point that he believes ocean mixing has been overestimated also means that more warming from CO2 emissions to date is still "in the pipeline", meaning that long term climate sensitivity is much higher than previously believed. So yes, there are indeed uncertainties and they have always been acknowledged. However, there are LIMITS to the uncertainties.



The problem, as is always the case in science of this type and complexity, is that you have to consider "the

I've lost the rest of my post again! It continued as follows:



The problem, as is always the case in science of this type and complexity, is that you have to consider "the big picture", with all the knock-on consequences from a particular finding. It is your consistent failure to approach the science in this way which leads you to draw the wrong conclusions. More of which..........



"my issues revolve around procedure, data manipulation and the conclusions drawn from them- to which I am eminently qualified to comment on- more so that the core team as I ACTUALLY have substantial QA training."



This is an argument you consistently fall back on........ and this remains my biggest concern about your position on this subject! You are, in effect, appealing to your own authority here. I would remind you that I have worked in QA, have lectured in microbiology and have worked in scientific research. I don't claim to be an expert on any of them, but I know more than enough to say with certainty that someone who works in QA in a controlled and closed laboratory system does NOT possess authority when it comes to novel scientific research studying a dynamic and infinitely more complex system. The two are completely different sciences and necessarily employ entirely different methods, data manipulation and reporting.



"To put it another way, I’ve never lost data in my (scientific) life and do not use my work email to slander ‘opponents’ and suggest potentially prosecutable actions."



I am also quite sure that you have not had to defend your work against an organised denial movement. Nor will you have been subject to death threats or had to endure unwarranted attacks on your personal integrity being posted right across the internet!! Please stop trying to occupy the moral high ground here, LabMunkey. It may suit your argument, but it doesn't ring true in the real World!



Paul

The latest article at Skeptical Science is highly relevant to this discussion:



https://skepticalscience.com/Can-we-trust-computer-models.html



Paul

74. QuaesoVeritas:



I agree that a common base period would be useful in the main data sets.

89. Paul Briscoe:



Thanks for the link; and the above was very well argued btw.

#89 - Paul Briscoe wrote:

"The latest article at Skeptical Science is highly relevant to this discussion:

https://skepticalscience.com/Can-we-trust-computer-models.html"

Now, I haven't had a look at this yet, but given the source, can I guess

that the answer is yes?

Of course, I am prepared to be surprised.

Paul @ 87.



I’m not dressing anything up- you’re not READING WHAT I PUT. You are aware, perhaps, that a significant number of the contributors are not climate scientist’s right (they are simply scientists in other fields). Further, I have already pointed out that the agenda is set by a minority of the establishment, therefore it is entirely possible for the vast majority of the underlying science to be sound, but the interpretation of it and the conclusions made of it to be fallacious.



The distinction you’re looking for here (and missing by a country mile) are “ climate establishment” and “contributors to the IPCC documents”. These are not one and the same.



Re- uncertainties: No Paul, they haven’t. They DO add the ‘get out of jail’ sentence into SOME of their work, but the uncertainties are by no means at the forefront of their work and conclusions- as it should be.



Re- Big picture; You’re being quite (unintentionally) insulting to suggest that I am not capable of understanding ‘the big picture’. You do not know the nature of my research or the environment in which I work in (though I would hardly expect you to take my word for it on an anonymous blog).



I know, from bitter bitter experience that if you do not pay exceptionally strict attention to the small details- that regardless of how big of a picture you keep in your idealised vision, that you are doomed to failure. It takes ONE error Paul, ONE, for this whole theory to fail. You do appreciate that right? Or are you of the opinion that the theories too big to fail now?



Re –QA. You’re right; I cannot claim to be an expert on QA. I can however, claim to be significantly more qualified than the core climate science team on this matter. These two claims are distinct and separate. Given the evidence freely available on the team, their practices and behaviour I would humbly suggest that my technicians are more qualified wrt QA than the climate team. This IS pertinent.



“I am also quite sure that you have not had to defend your work against an organised denial movement”



You were doing so well Paul. You argue, on the whole, eloquently and with thought- you often support your work with references (we may disagree on the significance of them or their relevance) but the process and procedure is there- which is why, on the whole I enjoy debating with you. But then you go and do something like this and

I am again splitting this post, in order to avoid truncation.



PART 1



I have been doing some further work on assessing the accuracy of the temperature models in IPCC scenario A1B.



Initially I considered calculating coefficients of correlation, but I realise that they wouldn't really tell me anything about how accurate the figures are,

just how they relate to one another. You could add 100c to every predicted figure and the correlation would be the same.

For the record however, the coefficient of correlation of the Multi-Model Mean to HadCRUT annual anomalies, over the entire period 1900-2010, is 0.905.

However, that hides the fact that over 10 year periods, the coefficient varies considerably, between +0.88 and -0.57.



Also, while calculating the cumulative mean error would demonstrate any bias, since positive and negative errors would offset one another the results could be misleading. You could have an average error of zero, but with huge positive and negative errors which compensate each other.



In the end, I decided to do this by calculating the Mean Absolute Deviation for the model predictions. This seems to be an accepted way of calculating the accuracy of forecasts in the business world and would not have the above problem. For the purposes of the exercise, I calculated annual, cumulative and 10 year rolling averages.



As a result of these calculations, I found that the MAD for the MMM, over the period 1900-2010 was 0.102c, although again, the 10 year rolling MAD shows

considerable variation, falling to 0.055c by 1927, rising again to 0.247c by 1945, falling again to 0.036c by 1995 and rising again to 0.092c by 2010.

The overall impression is that there is little consistency in the annual absolute deviations.

PART 2



I then looked at the MAD figures for individual models, which seems to make the situation even more confusing. Three models stand out as having very high cumulative MAD figures for the entire period. These models, with MAD figures in brackets, are:



cccma_cgcm3_1_t63 (0.300c)

cccma_cgcm3_1 (0.258c)

cnrm_cm3 (0.251c)



All of the above models had MAD figures of about 0.4c between 1900 and 1940, then cnrm_cm3 gradually fell, but the other two stayed around 0.4c until about 1960 before falling. Reference to the actual anomalies for these models showed that they all UNDERSTATED temperatures during much of the 20th century and were far below other model forecasts for the first half of the century, which accounts for the high MAD.



All of the other models end up with cumulative MAD figures of between 0.147c and 0.066c by 2010, which are generally centered around the MMM MAD of 0.102c. However, several of the models show MAD figures of 0.2c to 0.3c during the early part of the 20th century, and around 0.2c by the middle of the century. The next two models in terms of the size of the overall MAD figures are:



miroc3_2_midres (0.147c)

iap_fgoals1_0_g (0.141c)



The worst performing model based on the 3 year mean anomaly at 2009, miroc3_2_hires, (see my previous posts), actually has a fairly normal MAD of 0.112c, because it's performance during the 20th century wasn't too bad.



On the other hand, the 5 models which showed the best overall performance based on MAD, were as follows:



ncar_pcm1 (0.066c)

giss_aom (0.078c)

mri_cgcm2_3_2a (0.08c)

ukmo_hadgem1 (0.081c)

ncar_ccsm3_0 (0.093c)



Note that only one of the "worst" models based on the 2008-10 mean (see my previous posts), is on the above "worst" list, and one of the models on the 2008-10 "worst" list is actually on the above "best" list!

PART 3



Unfortunately the above analysis only seems to make the overall situation more confusing, with very little apparent consistency in the models regarding good

or bad performance. In my opinion this is itself an indication of the unreliability of these models, since if they were correct, I would have assumed that they would show consistent performance over time.



Nevertheless, out of interest, I did calculate the MMM which would result from using only the above 5 most accurate models and this produced a 3 year average anomaly of +0.376c by 2009, compared to the full scenario A1B MMM of 0.431c, and the actual HadCRUT3 anomaly of 0.26c. However, while this did produce a slightly better predicted anomaly for 2008-10, it was still an overestimate of about 0.12c and in some cases the predictions over the period 1980-2010 were worse than the actual A1B MMM.



Given the extremely wide range of outputs and past accuracy of the models used in this scenario, I think that if the resulting MMM turns out to be accurate, it will by by a sheer luck. There is no apparent historical consistency between the models, with high figures on some, cancelling out low figures in others, so that personally I have no faith in the future accuracy of any of the models involved. I know that the A1B MMM overstates temperatures, and I know that most of the models are inaccurate at various times, but they appear to be INCONSISTENTLY inaccurate, so it is very difficult to say which models should be removed to reduce the bias shown in the MMM. Moreover, I don't think that a forecast, which relies on model inaccuracies to compensate one another is likely to be very reliable. The whole approach of using many different models, seems to be to average out the inaccuracies of the individual models.



I think that it is erroneous to assume that more models and more complex models, equal more accurate forecasts and maybe it would be better to concentrate on fewer more accurate models, if they could be identified. Surely averaging out the multiplicity of models doesn't necessarily make the forecast more accurate? What is the point in having super-sophisticated, highly complex models, producing detailed forecasts, only to average out all of the differences by combining them into a single MMM figure? The calculation of a "simple" polynomial trend based on past temperature figures produces a very similar curve to that produced by the MMM and might produce more accurate and more comprehensible results.

PART 4



I haven't looked in much detail yet at the 10 year rolling MAD figures for individual models. If that produces anything interesting, I will post here.

If anyone knows of a more appropriate method of evaluating the accuracy of these models, I would be grateful to hear from them.

#92. I wrote:

"#89 - Paul Briscoe wrote:

"The latest article at Skeptical Science is highly relevant to this discussion:

https://skepticalscience.com/Can-we-trust-computer-models.html"

Now, I haven't had a look at this yet, but given the source, can I guess

that the answer is yes?

Of course, I am prepared to be surprised."

Well, I have read the article and I wasn't surprised.

You, given my previous posts, which were sent before I read the article, will probably not be surprised that I disagree completely with the conclusion.

In particular, I disagree with the following:

"The IPCC AR4 report evaluated the climate models used for their projections, taking into account the limitations, errors and assumptions associated with the models, and found that:

“There is considerable confidence that AOGCMs provide credible quantitative estimates of future climate change, particularly at continental and larger scales.”

This confidence comes from the fact that the physical laws and observations that form the basis of climate models are well established, and have not been disproven, so we can be confident in the underlying science of climate models.

Additionally, the models developed and run by different research groups show essentially similar behaviour. Model inter-comparison allows robust features of the models to be identified and errors to be determined."

The only way that the IPCC could come to these conclusions is if they were pre-disposed to that belief, which presumably they were, otherwise they wouldn't have used the models.

I believe that anyone who looks at the details of these models, with an open mind, would come to a contrary conclusion.

I think that the IPCC are confusing complexity and the fact that they may be theoretically sound (which I don't necessarily disagree with), with actual accuracy.

In my view, "the proof of the pudding is in the eating". All of the right ingredients can go into a pudding, but it can still turn out wrong.

@ continuing my #93



seems my posts are being truncated now too- perhaps the foreshadowing of the dreaded 400 char limit...



... you lose all credibility.



I have been subject to many hostile audits (a normal part-and-parcel part of cGMP life, not an indication of any wrong doing!), some by Japanese companies- if you think that the 'organised denial' movement has anything on this kind if scrutiny then you're so sadly mistaken as to be worrying.



A real-life example; i was once producing a batch of material for a Japanese company and a mistake had been made on the fill-finish documentation- the wrong date on a QA-check (so easy to do in the beginning of a new year) and they rejected the entire batch because of it. Thousands of pounds worth of material rejected because of a harmless mistake.



This is the kind of level of scrutiny i work am used to working under. I would humbly suggest that the climate scientists are getting a very easy ride...

LabMunkey



“I’m not dressing anything up- you’re not READING WHAT I PUT.”



I did indeed read what you had written……. and therein lies the problem.



It is irrelevant who you believe your statement at the start of post #1 referred to – it is arbitrary and defamatory whoever it referred to! The statement implies, for example, that James Hansen himself is part of the climate science establishment and that he is not usually honest. It also implies that lead authors of IPCC AR4 WGI, such as Kevin Trenberth, are habitually dishonest. You may not agree with what these people say, but there is NO evidence that they are anything other than sincere.



Against my own better judgement, I even went to Climateaudit to see what point you were making about Pachauri and other IPCC leaders. I found nothing I didn’t know already. I see evidence of some sloppiness in the preparation of AR4 WGII and an over-reliance on non-peer reviewed literature, but I have seen no evidence of deliberate dishonesty that would justify your opening remark. As I stated above, many scientists believe the IPCC is UNDERSTATING the threat.



Paul