Monday, February 1, 2010

How many gates?

Yesterday: The TimesOnLine published more damaging evidence:

January 31, 2010: UN climate panel shamed by bogus rainforest claim


Anonymous said...

You guys do seem to be getting it. We have been deliberately conned by the pro-CAGW movement.

Examples are very common:

1. The MBH 1998 Hockey Stick.
2. The Steig Antarctic paper of 2009.
3. The claims of sea level rise affecting island nations.
4. The 'problems' faced by polar bears.
5. Himalayan glaciers.
6. Bangladesh.
7. Amazon rain forest.
8. AGW associated 'disasters'.
9. Rejection of historic CO2 data.
10. Ignoring local subsidence and emergence as factors in sea level changes.
11. Great Barrier Reef.
12. Australian droughts.
13. Failure to archive data, code to allow replication - too many examples to list. See CA.
14. Failure to provide proof that CO2 is a significant cause of warming.
15. 'Tampering' with the temperature record.
16. Inclusion of unverified and false information in IPCC reports.
17. Summary for Policy Makers that misrepresents the information in the body of the report.

Add to all that the many claims made that 'there is a consensus' that 'the science is settled'.

It goes on and on....... How can anyone say that all of the revelations of bad practice and malfeasance 'don't change the overall conclusion'.....

Marco said...

1. Vindicated. One can discuss the methodology, but even the correct centered PCA gave the same result
2. Nothing wrong with that
3. Unless you solely believe dowsing expert Nils-Axel Mörner, and not a single other oceanographer, a real threat
4. Real problems. Despite protection against hunting, there is a decline, which is mainly due to loss of food sources
5. 2035 or 2350, does it make you feel better your greatgrandchildren won't see them disappear just yet?
6. What is supposedly the issue there?
7. Somewhat less vulnerable than the IPCC claims. Gee, how wonderful. You don't die in 1 hour but in 3
8. One's disaster is another's happiness...
9. And rightfully so. Beck's paper should be an embarrassment to E&E, it had already been falsified before he ever wrote it!
10. It is not ignored!
11. Is still bleaching.
12. Are still on the increase
13. If CA claims data and code were not archived, they are lying. They have been and are.
14. Basic radiation physics
15. No tampering observed; instead, major failures to understand the (really not that hard) science exposed in Watts, D'Aleo, and E.M. Smith
16. Repetition
17. SPM often downplayed the actual statements in the body of the work.

Werner Krauss said...

Your dialog, Anonymous and Marco, is good to think with. If this is a dialog at all.

Position 1 wants to make climate change disappear from the political agenda. Every mistake, contradiction, flaw, manipulation of data etc is taken as a proof that anthropogenic climate change is a fake.

Position 2 thinks that climate change should be a matter of global concern and be part of the political agenda. There is a permanent effort to find new proof of (man-made) warming, to correct incorrect data, to reform the IPCC in order to make it a better instrument, and, of course, to find solutions how to cope with the problem.

In my understanding, position 1 is destructive, per se. Am I right, Anonymous? You will never concede that anthropogenic global warming is a problem for humanity. You jump on the bandwagon of critical (not to say: skeptical) scientists to foster your purely negative agenda.
You will take every discussion to turn it against the protagonists of climate change politics. Correct me if I am wrong.

Position 2 has already won the battle, somehow. Copenhagen and all previous summits were real (whatever their success was); climate politics are part of national and transnational politics; climate change is already a matter of global concern; climate science is funded by the respective taxpayers. This was a political decision. There is still a lot of room to design climate politics, of course. It can only become better. But the decision is taken - initiated by science, but taken by politics.

The dilemma for climate science is that it became the battleground for this political power play. Science became an instrument of politics. It cannot solve the problem imposed by the skeptics, because this is a political problem. Most of all, the agenda of climate science has become a political one; every effort to understand climate better becomes part of this power play between two irreconcilable positions. This is due to the skeptics, in my opinion. Alarmists and skeptics are not the two sides of the same medal. Skeptics destruct, while alarmists only try to steer the ship the majority already decided to navigate on. These interventions are of different quality. There is no dialog possible between those who are on the ship and those who want to sink it.

Anonymous said...

Actually Werner, I didn't explain my position. Rather than surmise, here it is.

1. Man IS having massive impacts on local and regional climate, in various ways mostly related to land-use. Kilimanjaro is a very clear example. Desertification in various areas another. Deforestation and disturbance of natural hydrological cycles another. Roger Pielke Sr provides ample evidence and discussion of these issues.

2. The case that anthropogenic CO2 is causing climate problems is NOT proven. All we have a assumptions included in models that try to replicate history. In particular, the assumption regarding sensitivity of Global Mean Temperature to CO2 levels is unproven.

3. The advocacy agenda of the IPCC, much of mainstream media, 'environmental' organisations such as WWF and Greenpeace, and many others has resulted in us all being regaled with 'junk science' and it had become acceptable for 'climate scientists' to 'exaggerate' in order to alarm the people, and mobilise governments to take action. Al Gore and Stephen Schneider particularly have made clear statements to that effect.

4. The inordinate emphasis on CO2 has distracted attention from the real problems. It is high time that we had real and objective science into the real issues.

My first post was designed not to argue the case. Rather to list the many examples where dodgy practice has been made evident. Given space limitations, I did not provide chapter and verse. However, anybody with google can find out that there is at least a divergence of views on all the issues raised, and in many cases, the claims by the warmists have been completely rebutted.

So I am NOT what you would call a 'denier'. I am a sceptic, when it becomes evident that I have been lied to, misled. When I see that 'climate scientists' have engaged in advocacy and manipulation and misrepresentation of the data. When they refuse to disclose key data, methods and code. When they selectively reject the 'inconvenient' part of the data record.

Some 'climate scientists' have revealed themselves for who they are and are facing the consequences. By their fruits ye shall know them.

It is high time that we focussed our resources and government attention on real issues that actually can cause major problems for mankind. CO2 is NOT that problem.

itisi69 said...

SPIEGEL: Why is it such a taboo to ask about the positive effects of climate change?

Storch: The reasons are likely rooted in religion. Playing around with God's creation is simply not allowed. Incidentally, in the past it was precisely the deeply religious people who said: Of course we're playing with God's creation, in fact we're perfecting it. This sort of thinking is frowned upon today.

SPIEGEL: Aren't climate researchers helping fuel a state of panic with their generally bleak warnings?

Storch: Unfortunately many scientists see themselves too much as priests whose job it is to preach moralistic sermons to people. This is another legacy of the 1968 generation, which I happen to belong to myself. In fact, it would be better if we just presented the facts and scenarios dispassionately -- and then society can decide for itself what it wants to do to influence climate change.

(Hans von Storch interview in Der Spiegel 03/16/2007)

Anonymous said...

Bjorn says:

Regarding no. 14 ("Failure to provide proof that CO2 is a significant cause of warming."), I am more than eager to get a complete understanding on the scientific cause for CO2 being the predominant greenhouse gas. I am a physicist, I had many courses on atomic and molecular physics ('basic radiation physics'), although my specialty was non-linear dynamics, statistical physics, time-series analysis and computer modelling.

And still I find it hard to grasp that such a simplistic picture as a 'radiance balance' --- maybe best characterized as first-order physics --- can desribe reasonably well the atmosphere. I was working in some of the most famous European Statistical Physics departments, and yet met only one single person who was interested in non-equilibrium thermodynamics, apart from some scientists who studied relaxation of dynamical systems near critical points in phase transitions. The issue is that in non-equilibrium thermodynamics, equations tend to be very complex and without simple mathematical solutions.

The atmosphere is constantly off-equilibrium as a consequence of Earth's rotation, solar energy flux, convection, regionally differing albedo, clouds and so on. Radiance, on the other side, is a highly non-linear (T^4) and hence local phenomenon. There are no closed mathematical solutions for the full Navier-Stokes equation that desribes the atmosphere. How could it be that simple radiation balances could describe reasonably well what happens at the outer atmosphere?

Are you really, really sure that you have fully understood the 'basic radiation physics' of Chandrasekar and why it correctly describes the outer atmosphere? I would be more than grateful for a deeper discussion than the nice coloured pictures that I have found in the IPCC's Assessment Reports and that make me feel uncomfortable in such a complex context.

Werner Krauss said...

Thanks for your detailed response, Anonymous. I have to think about it for a while. Don't know exactly what to make out of it. In a certain sense, you did confirm my first post, didn't you? Here a recent quote from Hans von Storch, as a contrast to your opinion:

"The scientific construct of human-made climate change is widely supported within the relevant scientific communities[ix], and has been comprehensively formulated particularly thanks to the collective and consensual efforts of the UN IPCC. According to this construction[x] human beings are changing the global climate. Climate is the statistics of the weather. In almost all localities, at present and in the foreseeable future, the frequency distributions of the temperature are shifting to higher values and will continue to do so; sea level is rising; amounts of rainfall are changing. Some extremes such as heavy rainfall events will change. The driving force behind these alterations is above all the emission of greenhouse gases, in particular carbon dioxide and methane, into the atmosphere, where they interfere with the radiative balance of the Earth system."

So Hans von Storch is also one of these CO2 alarmists? And obviously he is in favor of the IPCC, which represents according to him scientific consensus. According to his statement, you are not part of the scientific consensus in this question.
You argue against the (global) CO2 thesis in general. This is definitively different from the critique recently made by Hans von Storch, I guess, who criticizes colleagues and the IPCC, but on a shared common basis - CO2 is the villain, and the IPCC is something we need.
Right? Or am I still on the wrong track?

Anonymous said...

Werner. Thank you for your response. To state my position even more simply:

The climate is part of a very complex earth/solar system about which there is much that we don't know.

I am all for investing resources in sound science in order to understand the impacts that man is having on the environment, and then taking appropriate action (where practicable) to deal with those impacts.

I am not interested in advocacy or agendas. I am sick of 'science' that doesn't meet the most basic requirements of the discipline. I am tired of bs and lies.

I am happy to take action to deal with real problems. But lets establish that they ARE real problems first. Let the chips fall where they may.

And PLEASE, can we create a climate where the issues can be discussed dispassionately and professionally.

itisi69 said...

"11. Is still bleaching."
Because of AGW? Or from the cold:

Werner Krauss said...

Anonymous, I agree that things have to be discussed dispassionately and especially professionally. But professional also means to answer the questions I asked; I am afraid that you didn't. I asked you to position yourself in relation to Hans von Storch's statement above. This is a legitimate question, don't you think so?
Sorry for insisting; I am really interested in the nature (and the limits) of the dialog between the different groups involved in this discussion. I understand that you are sick of agendas; but is it possible to be without an agenda in this business?

Marco said...

Sometimes real life may be more complex than the simplifications of science, but at the same time those simplifications do quite well in grosso modo describing real life.
An important issue of CO2 as the main driving greenhouse gas (which is not the same as the main greenhouse gas) is that it explains a lot of observations about the past. Take any radiative forcing of CO2 away, and suddenly we have a lot of trouble explaining interglacials and the temperatures on earth even further back. That is, we have (perhaps simplified) equations that do a reasonable job in modeling the earth's atmosphere, even to the extent that we can predict short-term weather quite well(!), and that also provides a quite good explanation of observations of the ancient past. That's certainly much more evidence than "it's all so complex, we really do not understand it, don't even try".

Marco said...

cold probably isn't all that well for coral either. However, warming events are much more common.

itisi69 said...

"However, warming events are much more common."
More or less common, doesn't really matter. Question is why warming is anthropogenic, catastrophic, beyond repair and cold is natural and not even mentioned in the global press and on "Save The World" climate summits?

Anonymous said...

Werner. You asked me to comment on my position relative to the position adopted by HVS on CO2.

I had thought that the answer was implicit in what I wrote. However, to be explicit: The CO2/carbon cycle is complex, and it is my impression that we really don't know very much about it.

There is dispute about even the variability of CO2 levels in atmosphere over time, and from place to place as Beck points out. I realise that Beck is 'discredited', but perhaps he is correct. My understanding is that all he is doing is pulling together historic measurements of CO2 in atmosphere.

But more importantly, do we really understand how CO2 actually operates to affect global mean temperature? For example, Bjorn (above) makes some interesting observations.

Also, we hear about the logarithmic decay of the warming effect of CO2 - characterised as adding additional curtains to keep the light out. But this does not seem to be taken into account in the models. Or perhaps it is.

My most serious concern is that those concerned about the problem have been asked for some time now to provide a detailed 'engineering feasibility study' quality exposition proving that doubling CO2 levels will lead to a rise in global mean temperature of +/- 5 deg C. Now my understanding of the physics is that it is generally accepted that doubling can lead to around 1 degC warming, some 75% of which may have already happened. To get to 5deg C requires assumptions about positive feedbacks. This is a controversial area, and it seems that some argue that feedbacks are actually negative or neutral (meaning no warming from CO2 increases). It would seem that this aspect of the science is not settled.

At another level, I really find it hard to believe that a trace gas, present as one part per 2631 parts, can really have such a massive impact as to cause global mean temperatures to increase by 5 deg C.

So yes. I do not accept the 'consensus' view on CO2's role in warming.

The flaws/problems with the temperature record bring into doubt even if there is warming. And if there is, it seems that it is regional, not global. Though none of the warmists ever talk about that.

In the context of what is emerging about poor quality science and misrepresantation of results etc now burgeoning around the globe, are you really surprised that I am a sceptic??

I trust that I have now answered your question.

Marco said...

@itisi69: Could you please give some examples of the dichotomy you claim?
From what *I* have seen and read the climate science field is filled with warnings that global warming does not mean that all areas will warm. Some will, some don't, some may even cool. For *most* of the coral reefs, warming events are a much graver danger than cooling events, simply because the former occur more frequently. That warming is "beyond repair" is a mockery of the warnings sent out by climate scientists. However, we should be aware that even stopping CO2 emissions completely will not immediately stop global warming. Just like stopping CFC emissions doesn't mean the ozone layer started to repair itself right away.

But maybe I'm just one of those people who looks beyond the screaming headlines and actually reads the report including all the qualifiers ("Likely", "ossible", "perhaps", "may", etc.).

itisi69 said...

Marco, have you been on this planet lately? Ever heard of Jim Hansen's "Tipping Points"? "Copenhagen is the last chance to Save the Planet" (Stern, Brown)?

"But maybe I'm just one of those people who looks beyond the screaming headlines and actually reads the report including all the qualifiers ("Likely", "ossible", "perhaps", "may", etc.)." So do I, and therefore those reports are not very usefull and disingenious. Like me saying: Like, possibly, perhaps I can win the Lottery.

Werner Krauss said...

Thanks, Anonymous, you indeed answered my question. I am a slow thinker, obviously, so I had to ask the same question twice.
I cannot really follow you on the field of the scientific Co2 discussion, I am kind of handicapped in the world of numbers. But I am (hopefully) pretty good in the slippery field of culture.
That's why I am so persistent and want to come back to the question of the 'agenda' - part of my question you did not answer explicitly. Doesn't everybody in the climate business have a hidden or open 'agenda'? The observations, calculations etc. are mostly done in relation to someone else's calculations, isn't it? Sure, you are indeed a 'sceptic'; others are indeed 'alarmists' or something that is more difficult to label, such as Hans' position (neo- or post-sceptic maybe??? -:)); however, everybody in this business indeed seems to have an open or a hidden agenda. Do you agree?

Marco said...

Itisi69, you are pointing to some examples, but fail to prove your claim that only warming is mentioned in the media, and always as catastrophic etc etc.

itisi69 said...
This comment has been removed by a blog administrator.
Dennis Bray said...


I would say there are some climate scientists that do science for science's sake. They are interested in generating new knowledge and understanding. Of course this is an opinion and I have no facts to back it up. I think you would find this type of scientist is not seeking glory, fame, notoriety, etc. and hence is typically quiet and unheard of in the political foray of 'public' climate science. Maybe we should always qualify which side of science we are talking about. Then again, maybe I am just naive in imagining such a science in this day and age.

Marco said...
This comment has been removed by a blog administrator.
itisi69 said...

*sigh* I give up...

yes Marco, there was a fair and balanced discussion in the media the last decade where contrarian and sceptic climate scientists have been given ample room for their view without the danger of being outcasted by the likes of Schmidt, Rabett, Tamino, Monbiot, Revkin et al, or being called a "denier", "flat-earthener", "schoolboy scientist", "prat" or worse. Nothing of this happened, I'm sorry, I was wrong...


Marco said...

@itisi69: I've seen many (really many) articles which quoted Lindzen, Spencer, Christy, even Singer throughout the last decade. Revkin even frequently refers to several of these people!

I also challenge you to show me where Gavin Schmidt calls a 'contrarian' or 'skeptic' climate scientist a "denier", "flat-earthener", "schoolboy scientist", "prat" or worse. If you cannot find such quotes, I expect you to apologise.

I also don't see why tamino and rabett using the occasional strong terminology somehow supports your initial claim about the information. I could point to Wattsupwiththat and climateaudit as some counter-examples (with the former several times worse than tamino or rabett).

Substance, please, not unsubstantiated smears.

Anonymous said...

Werner. Re your question in 17 about my agenda (note - this is the second time I have prepared this. When I pressed 'publish' it told me that there was a conflict. Delete if this is a duplicate).

Do I have an agenda? I'm not sure that I do other than wanting to learn the truth of the matter, whatever that may be.

I am a retired professional engineer. In the course of my career I was involved in quite a few feasiblity studies up to $1 billion.

Anyone who has been involved in such studies knows that they are subject to stringent due diligence. The financiers (generally the banks) engage a independent group to go through the feasibility study to check the calculations, and to generally confirm that the feasibility study is soundly based. The due diligence process includes engagement of a specialist model checking firm who go through the financial models line by line to check they are right.

Further, in the later stages of my career I spent quite a bit of time in the commercial/financial world, and frequently participated in due diligence exercises, often involving teams of lawyers. For example, in preparing prospectuses for equity fund raisings, the standard requirement is to prepare a hard copy due diligence file that provides the supporting documentation for every material statement made in the document. This is designed to protect directors in the event of later legal action in that they can prove that they did what a reasonable man would do to check the facts underlying those material statements.

Anybody who has worked in the project financing world can confirm the truth of my statements.

I think that you will find that many skeptics are retired engineers. For a start, they generally DO have strong backgrounds in science, particularly physics and chemistry, maths and statistics, as well as model building and testing. They are not klutzes.

Second, the fact that they are retired means that they have the time to delve into the debate in more detail than most.

For my part, I have been following the climate debate for over ten years now. This mainly involves spending several hours each day participating at the various blogs on both sides of the debate. I make a point to visit blogs on the 'warmist' side and also on the 'sceptic' side. I also read the primary literature where I can, and I am a close observer of how the mainstream media handle the issues.

I have been somewhat surprised at the lack of critical thinking demonstrated by many of those concerned about anthropogenic CO2 emissions. One of the questions that I ask people who are concerned about CO2 is 'how do you know it is a problem'. The answer that I generally get is that 'the IPCC says so' or 'the climate scientists say so' or 'the science is settled' or 'there is a consensus'.

What I DON'T see is independent due diligence to an engineering standard. I DON'T see climate scientists even making the case as to why they make the assumptions regarding feedbacks that they use to justify their +/- 5 degC warming from a doubling of CO2.

In the course of my career I have had quite a bit to do with Pacific Islands, and understand that these are (as Darwin said) generally built as coral atolls on the tops of volcanic edifices. These can rise and fall causing changes in local sea level. Sea level is an interesting example of the lack of critical thinking.

I could go on, but I will cease here. My agenda is that I am interested only in the truth of the matter. Let the cards fall where they may.

Werner Krauss said...

To Dennis and Anonymous:

'I would say there are some climate scientists that do science for science's sake.' (Dennis)
'My agenda is only in the truth of the matter' (Anonymous)
Others state that they are only in it because they are curious.

I think this is worth another discussion: 'for science's sake, truth, pure curiosity' as opposed to 'agenda, interest, politics'. Are they really opposed, or shouldn't we see them as different, but related? This is a new discussion, I guess.

So far, thanks for the interesting conversation, Anonymous; I appreciate your openness!

Marco said...

@Anonymous: if you want to know where the climate sensitivity comes from, you can start here:

Anonymous said...

Also. I am prepared to post under my chosen pseudonym. But this site doesn't seem to allow that.

itisi69 said...

Lindzen: "Climate of Fear", "Global-warming alarmists intimidate dissenting scientists into silence."

"I also challenge you to show me where Gavin Schmidt calls a 'contrarian' or 'skeptic' climate scientist a "denier", "flat-earthener", "schoolboy scientist", "prat" or worse. If you cannot find such quotes, I expect you to apologise."
You are surely joking. Read my message again, I never said Schmidt utter those words. I mentioned several people. All these words are used by the AGW cabal.

Ben Santer even goes phisycally: "I looked at some of the stuff on the Climate Audit web site. I’d really like to talk to a few of these “Auditors” in a dark alley." or "I’m really sorry that you have to go through all this stuff, Phil. Next time I see Pat Michaels at a scientific meeting, I’ll be tempted to beat the crap out of him. Very tempted. "

and then the infamous words of Jones: "I can’t see either of these papers being in the next Intergovernmental Panel on Climate Change Report. Kevin and I will keep them out somehow—even if we have to redefine what the “peer-review literature” is! "

Keep on trolling Marco

Marco said...

Have you checked why Santer et al makes the comments about the "auditors" at climateaudit? You seem to be rather hypocritically critical of strong words by "the AGW cabal", and don't mind the same strong words from the other side. Moreover, you are quoting private e-mails, which often use figurative language. "I'd rather chop my arm off", a common expression, but certainly not something anyone would actually really do.
I hope you are also aware that Ben Santer has received death threats ever since 1996 because of his work on climate change. That reduces one's willingness to be kind to 'the other side'. Richard Allen recently showed an e-mail his university had received, demanding he'd be fired for lying about climate change. How wonderful!

Hans Erren said...

I assume that you are aware that a 3 degree climate sensitivity goes hand in hand with a huge 20th century sulphate aerosol cooling (Andronova and Schlesinger, 2001; Meehl et al., 2004)? And that sulphate emission in the Netherlands at the moment has reached the level of 1880 (D. Stern, 2005)?
So al warming since the 70's can be blamed on the sulphate cleanup?
Unless the sulphates don't cool that much, but then CO2 cannot warm that much.
Also the IPCC oligarchy has systematically kept land use change out of the equation (Pielke Sr), which brings CO2 climate sensitivity even further down

how to ollie said...

Excellent post and writing style. Bookmarked.

Marco said...

@Hans Erren:
The 3 degrees climate sensitivity comes from *many* different approaches. Meehl et al is just one of many such approaches. See also:

And I know Pielke Sr's claims, but apparently his claims don't find much support in the literature (see also his latest Klotzbach et al article, contradicting one of his former articles (Lin et al) after a mistake was corrected in the latter).

eduardo said...

@32 Marco,

how can you be so sure about the value of climate sensitivity? If you are so certain, you should then accept that all models in the IPCC AR4 are wrong. In this table I cannot find any with a a climate sensitivity of exactly 3 degrees

So there must be an uncertainty, for at least some of the models to be right. How large it is? There are several approaches to estimate the sensitivity, but all of them rely on assumptions that are difficult to prove: for instance, sensitivity is independent of forcing (glacial, recent and future), the Bayesian approach is correct (lots to discuss here..),

Perhaps was your argument rather that sensitivity is larger than 1 degree? Maybe, but then why do models have different sensitivities? Would you agree that at least some aspects
are not 'settled' ?

eduardo said...

@ 14

Anonymous wrote 'Also, we hear about the logarithmic decay of the warming effect of CO2 - characterised as adding additional curtains to keep the light out. But this does not seem to be taken into account in the models. Or perhaps it is.'

This effect is certainly included climate models. The logarithmic dependence of the CO2 forcing is due to the fact that currently most of the absorption of infrared radiation by CO2 takes place in the 'wings' of its absorption bands. To calculate the absorption and emission properties of CO2 in the atmosphere requires quite a lot of computing power and almost all models apply some simplifications.

Anonymous wrote :'The CO2/carbon cycle is complex, and it is my impression that we really don't know very much about it' . This is a bit of a sweeping assertion, I think. The carbon cycle is not completely understood, for instance there is no satisfactory explanation for the change of CO2 concentrations between glacial and interglacial periods (concentration difference of about 100 ppm). But 'we do not know very much..' is a quite personal view

Marco said...

I agree that there is a range of possible climate sensitivities, and that those differ amongst the models. However, the most likely climate sensitivity lies around 3 degrees, from the studies I have seen so far and think(!) I understand.
Of course, there is a lot to discuss here, but even with a mere 1.5 degrees climate sensitivity I think you will agree that we can expect major changes of regional climates and significant increases in e.g. sea level.

From a scientific point there thus is a lot still to discuss. From a policy point of view the question is whether to take the high, middle, or low estimate as starting point, or to wait until there is less uncertainty. This also depends on the possible outcome. Since I do not see much positive outcomes even with low climate sensitivity, I'd prefer we do something now.

Hans von Storch said...

I agree to your conclusion. As long as the sensitivity is significant - be it 1 or 6 degrees - there is reason for the public to decide on a climate policy, which means to consider the possibilities, advantages and disadvantages of the different options - reduction of emissions, adaptation, regional and global geoengineering and maybe other measures. The choice of the mix of measures is to large extent a value-based political decision, and does not follow directly from the scientific analysis.
This is the logic of the Honest Broker - which is to supply the political system with the needed knowledge to arrive at a value-consistent decision, but without saying which decision.
A significant issue related to the sensitivity is the timing of the warming. The higher the sensitivity, the earlier the expected impacts. Indeed, part of the political decision process is the timing of measures.

I recommend Pielke's book "The Honest Broker". Not expensive and a relatively easy read.