NASA James Hansen’s Former NASA Supervisor Declares Himself a Skeptic

[Mk]

Excuse me, you said relative size. How many scientists work in related fields? I would say that AGW is a much broader subject.

Weird. I swore that there were less climatologists than biologists.

 

[LowlyPion]

The more sceptics, the more research the better the theory unless it fails due to the inherent weaknesses such as those that plague the AGW theory.
I will not attack either man as the actions and words of those on both sides are available for all to judge and history will judge by future actions.

What holes? You look to have brought your own baggage.

I see nothing that definitely disproves the general concerns about AGW trends. Looks to me like you're picking a side just as unfailingly as you are accusing the IPCC of having picked one.

I think it's certainly a good idea to challenge all of the data and to reassess as more data is collected.

But let's face it. This entry at the Republican Minority site is not news. And not news of any particular merit. And not particularly timely.

I think real meaningful news would be if Steven Chu or John Holdren were skeptical of AGW claims. Not some milquetoast warm as spit email from a 15 years retired administrator that got seized upon by Republican Wing nuts to exploit their political refusal to accept anything to do with AGW.

 

[LowlyPion]

He didn't review his performance but, more importantly, he , "...had to justify his funding, allocate his resources, and evaluate his results..." Theon was the Chief of the Climate Processes Research Program at NASA Headquarters and former Chief of the Atmospheric Dynamics & Radiation Branch. A man at that level should have something to say about one of his underlings' embarrassing activities.

That's grasping I think. There are hacks at all levels. The man was an administrator at that point in his career.

And why is it news now? Where was it he was speaking out on the subject 15 years ago? If he is so convinced where was he 15 years ago on not funding Hansen when he allegedly had authority not to do so? If he was so embarrassed.

The real problem here is this Republican Minority cherry-picking and inflating self generated hype, trying to whip this up as anything meaningful at all.

 

[Andre]

Wouldn't it be an idea just to look at the scientific ideas instead of the mud throwing? After all,

"Great minds discuss ideas. Average minds discuss events. Small minds discuss people." -

-- Eleanor Roosevelt

 

[LowlyPion]

Unfortunately I think the science of it looks to have been lost in the initial article which was put up on the Republican Minority site. The premise of the article and its posting here from the beginning seems somehow to want to discredit Hansen because an administrator 15 years ago now says he is embarrassed. The science of it seems not to be their concern.

 

[drankin]

Unfortunately I think the science of it looks to have been lost in the initial article which was put up on the Republican Minority site. The premise of the article and its posting here from the beginning seems somehow to want to discredit Hansen because an administrator 15 years ago now says he is embarrassed. The science of it seems not to be their concern.

Your continual political bias makes any of your posts suspect. I hope I'm not the first one to point this out. You somehow tie everything contrary to your opinion to those wretched Republicans. I think you have a point most of the time but as soon as you throw in Bush, Cheney, Palin, or the Republican party in general your comments begin to lose credence. No offense but just because something is condoned by the "other" party, that in itself does not make it without substance.

 

[vanesch]

One should make, I think, a distinction between being a skeptic of some of the quality of the science done, or the reasoning towards, the AGW claims, and the actual phenomenon.

If you say (like I do) that there are problems with the way certain conclusions of the AGW proponents are arrived at, then you belong to the first category. If you go about and claim that there is no such thing as an AGW phenomenon, you belong to the second one.

I can surely make a case for the first - I would have much more difficulty making a case for the second.

Just to mention - to me - the most obvious difficulty with an AGW claim, is the formulation of the probability distribution of the temperature rise at CO2 doubling, which is, if I remember well, 90% between 1.5K and 6K. Well, I surely contest the way that conclusion is arrived at. However, that doesn't mean that such a rise is not possible.

The essence of the error, IMO, is the following: one makes the implicit assumption that the computer models are unbiased, contain all the essential physics, and have correct error models. If you read the 4th AR of the IPCC, people arrived at those probability distributions by taking computer simulations in which there was (at least one) free parameter, the so-called "climate sensitivity". It gives you the rise of the temperature associated with a radiative forcing of 1 W per square meter.

This quantity is extremely difficult to establish, as it must take into account all kinds of feedbacks. So, *as one cannot calculate this number from first principles* one leaves it in
as a free parameter. The model contains certain physical phenomena, and other things which are modeled. Maybe it contains all of the essential physics, but maybe it doesn't.

Then, one runs this model on "calibration data", like paleo proxies, and the historical temperature record. Of course, the outcome of those runs will be dependent on the choice of the sensitivity parameter, the results of the calculation will not correspond exactly to the measurement results (because there are random variations, and measurement noise and all that). But from this fit, one can derive a "likelyhood distribution" of the parameter(s).

That is, for each value of the parameter, one calculates how likely it is (given the probability distributions of the noise, of the measurement errors etc...) that the actual data are generated by the model. So for each parameter value, one has the probability that the outcome is, by coincidence, equal to the actual data.

The "better" the parameter, the higher this probability of course, and the parameter value that corresponds to the highest probability is called the Maximum Likelyhood Estimator of the parameter.

Now, if you consider the parameter itself to have a (Bayesian) probability distribution, then one can show that:
1) if the model is unbiased and correct
2) if the probability model of the errors on the data is correct

that the normalized distribution above is also the Bayesian probability distribution of the parameter value. If that parameter value represents a physical quantity, then the thus calculated distribution is the correct probability distribution of that quantity (Bayesian: it represents the correct knowledge of the value of that parameter).

It is in fact nothing else but Bayes' theorem.

So from such an estimation, one has calculated the Bayesian probability distributions of the sensitivity to radiative forcing - and as one is relatively sure about the radiative forcing of a CO2 doubling (MODTRAN and the like), one can hence use the model again, with the given parameter and its distribution, to calculate the probability distributions of the resulting temperature rise for CO2 doubling, from the Bayesian probability distribution of the sensitivity parameter, and the probability distributions generated by the model.

That's what's done (if I didn't misunderstand the IPCC report).

So these give these famous 1.5K to 6K with 90% probability.

However, one has forgotten the premise of the theorem: one has to have *the correct model* and *the correct probability distributions of all the errors*, in order for this to work out.

It means that if a physical effect is not taken into account, or a simplification is made somewhere, or an erroneous probability model is given for the noise on the data (as well the calibration data - the proxies! - as the actual random variability in the workings of the model), that the calculation doesn't work. In fact, relatively small errors in the model (called bias) can result in relatively strong errors in the probability distribution of the parameters.

I don't think that one can claim at this point that the climate models are at that level of confidence, without the slightest bit of doubt.

That is why I put a big question mark against that specific prediction.
If one would have stated:
"in as much as the climate models describe the climate dynamics correctly, in an unbiased way, and with correct probability models, one can conclude that the distribution of the predicted temperature increase has 90% in the 1.5 - 6.0 K interval" that would have been scientifically correct.

Stating only that : "the distribution of the predicted temperature increase has 90% in the 1.5 - 6.0 K interval" leaves out an important qualifier IMO.

 

[Mike Davis]

As I was speaking of weaknesses not nessecerly holes and you feel that means holes we can discuss those.
The weaknes of relying on models trained on unverified historical data to project future events. The theory of seeing a trend while realizing that there are cycles involved in climate (unless so called experts are blind to cycles that are obvious to the unwashed like myself). I think I read that those cycles are considered noise. When there is a slight down trend it is maskig. when there is a slight up trend it is proof. Does that sound logical?
This brings up Paleo evidence. I suppose you can claim a consensus regarding the current papers used by IPCC to prove historical climate. If that is so why are people still searching and finding conflicting data? If the answer is found the search should be over. I think that the people searchig should continue but not demand action until the issues are a little better understood. By the way they should also consider more reliable advocates on both sides due to foot in mouth syndrome that is evident.

 

[Andre]

...
This brings up Paleo evidence. I suppose you can claim a consensus regarding the current papers used by IPCC to prove historical climate. If that is so why are people still searching and finding conflicting data? If the answer is found the search should be over. I think that the people searchig should continue but not demand action until the issues are a little better understood. By the way they should also consider more reliable advocates on both sides due to foot in mouth syndrome that is evident.

Read the Earth forums threads, when zooming in on the paleo climate of Neogene, you find nothing but contradictions. Actually there seem to be two paleo climate worlds, the zoological records versus the isotope records and never the twain shall meet.

 

[LowlyPion]

I think you have a point most of the time but as soon as you throw in Bush, Cheney, Palin, or the Republican party in general your comments begin to lose credence. No offense but just because something is condoned by the "other" party, that in itself does not make it without substance.

It's not my concern if you want to reflexively accept the politically motivated cherry picked propaganda churned out by the Republican Minority site at the Senate. Just don't purport that the puff piece about Hansen's supervisor's skepticism as indicating anything, but that the Republicans are trying to propagandize their position, and are offering no substantive science, other than attacking some bogus vague notion of consensus. It was just another opportunity for them to bump again their claim that they have 650 names - as if that really means that it changes the science.

Whoever posted the article as news is the one trying to pass off ideological propaganda as though it were scientifically relevant.

My point is that it is not.

 

[Mike Davis]

Andre:
Thanks for popping in. Reading your review of the Younger Dryas helped me to understand. Iwas referring to not only that but also the currnet era or the recent 6ky to 10ky to present. I may not get the language correct. but hope to be able to express the doubts.

 

[The Dagda]

well The IPCC was

The bold part may suggest that the conclusions were already clear before the research was done

No it doesn't seeing as they spent much of their early history denying man made contributions played a part. What you have there is just a speculative assessment, or your opinion. Climate change was a reality, but at that time their was far from a consensus on what was causing it. Eventually enough evidence came to light to make them shift their position from denying AGW was a concern to accepting that there was a real man made contribution.

First off, I'm not going to list my sources.

They were anti-GW until the early 90's!? Did the data from the last 10,000 years change all of a sudden then? Yes, I think that funding linked to political agendas could very well have something to do with their change in stance.

And yet I presume your sources are often funded by groups with an ulterior motive. Do you think though that all scientists working on this are deliberately shady, or that they have no conscience and are arguing despite the evidence for or against? We have to assume the evidence is although speculative at least meriting of concern, and we have to accept that some of the nay sayers are just as right and justified in bringing out concerns. The trouble is it's a wheat from the chaff deal.

I think I made it clear that this forum was not the sole source of my information.

The moderators on this site do a good job on insisting that arguments stated are supported and referenced. Especially when it come to GW, imho.

Good I still don't see how anyone can have made their mind up either way given the evidence we have atm, it's highly speculative and subject to revision. I know scientists haven't absolutely despite what you might read.

No, then we would have the current global warming argument situation.

Like I said before argument is healthy for science, it just behoves us to look at where the arguments are coming from and their motivations.

 

[Mike Davis]

I was taught and learned through personal past experience that the future depended on science as science was concerened with facts and theories. The politics was not considered unless it was an unbiased reaserch of the theories behind this phenomena. Science was considered the unbiased search for cause and effect. A search of historical events and theories of future events.
I guess that has all changed. There are those that are still searching but the sad issue is the appearence of personality issues displayed by some are over riding the science involved.
This piece we are discussing is as much news as any other gosip piece put out about anyone in public life. The more visable one makes theirself and the more eeratic the comments the more attention they bring to their past and current life. It is visable all around. It is possible the mentioned person may have been the cause for the interest.

 

[wolram]

There is some evidence that there is no concesus

http://epw.senate.gov/public/index....ecord_id=84e9e44a-802a-23ad-493a-b35d0842fed8

 

[Mike Davis]

No it doesn't seeing as they spent much of their early history denying man made contributions played a part. What you have there is just a speculative assessment, or your opinion. Climate change was a reality, but at that time their was far from a consensus on what was causing it. Eventually enough evidence came to light to make them shift their position from denying AGW was a concern to accepting that there was a real man made contribution.



I think you may need to take a closer look at history of IPCC. And why it was formed. Looking back to this persons testemony regarding climate change is a good start.
But you will probably still believe as fits.

 

[The Dagda]

1988 - The establishment of the IPCC
At its 40th Session in 1988 the WMO Executive Council decided on the establishment of the Intergovernmental Panel on Climate Change (IPCC). The UNEP Governing Council authorized UNEP’s support for IPCC. It was suggested that the Panel should consider the need for:
(a) Identification of uncertainties and gaps in our present knowledge with regard to climate changes and its potential impacts, and preparation of a plan of action over the short- term in filling these gaps;
(b) Identification of information needed to evaluate policy implications of climate change and response strategies;
(c) Review of current and planned national/international policies related to the greenhouse gas issue;
(d) Scientific and environmental assessments of all aspects of the greenhouse gas issue and the transfer of these assessments and other relevant information to governments and intergovernmental organisations to be taken into account in their policies on social and economic development and environmental programmes.

Seeing as the IPCC does no science of it's own and is made up of scientists from across the globe I think you need to ask whether there was a consensus amongst them in 1988, but there we go, some people have an agenda to suggest that these scientists and the organisation they represent are all in on some global conspiracy. So tell me, just what was the scientific consensus in 1988?

 

[Astronuc]

Project Scientist, IPCC Working Group II Technical Support
https://www.physicsforums.com/showthread.php?t=288420