"Our greatest responsibility is to be good ancestors."

-Jonas Salk

Monday, August 24, 2009

My Craven Rave at Last

OK, so I don't want to discourage people from sending me free books. That means if somebody sends me a review copy of something relevant, I read it and review it. So unfortunately I lost my free copy of Greg Craven's book "What's the Worst that Could Happen".

I finally gave up on finding the free copy. Fortunately, it's an inexpensive purchase at $14.95. And I have to say that I didn't mind paying all that much.

Now I'm not in the target demographic for the book (which will lead into my biggest disagreement with it) so maybe I'm not one to judge. On the other hand, it's easy to see Craven's influence in ClimateSight's writings, and she is off to a terrific start as a climate blogger.

Craven's approach is very much in line with something I've been saying all along. I refer to the idea of a "network of trust". No scientist really knows everything he or she claims to know from direct experience. Most of what we know as individuals comes from two factors: 1) a network of trust and 2) the test of coherence.

Don't get me wrong. What we know collectively comes from observation, experiment, theory and calculation. But what we know as individuals we mostly know because we learned it from someone else. People who don't learn from others don't learn very much.

Now, the nonscientist, the earnest and bright high school student, the wise and yet wisecracking high school physics teacher, your Aunt Maggie, don't have the second way of evaluating science.

The wise and yet wisecracking high school science teacher in question
Click the image for an amusing video demonstrating his style and hawking the book.

That's why Craven's book is about the first way of learning, what I call the network of trust.

Basically "what do you believe" comes down to a question of "who do you trust". Haivng made that point, he weighs the believability of the warmers and that of the no-warmers. Sure enough, when you actually start counting, the number of naysayers turns out to be, well, puny. As I once explained with this graph. While Craven touches on some of the issues in climate science, mostly he is about explaining the scientific culture.

Craven is right to do this. Despite the naysayers' constant harping on "focusing on the science", study of the details is really for the people who have developed sufficient grasp of scientific coherence. Which, I'm sorry to say, isn't guaranteed even for tenured faculty. Never mind high school kids. So how should a kid (or an adult!) who is honest enough not to just go with his or her crowd, who wants to get to the right side of what is obviously an enormously important substantive question, evaluate the competing arguments?

By trust, and trust alone. That's the only way to do it.

A big reason we are having so much trouble these days is because the networks of trust, especially the connections between science and society, but also the connections between any sort of authority and society, are in bad condition. I think if the national science academies of the main science producing countries on every continent unanimously agree on something, if the international body of scientists appointed by every country makes stronger statements every six years every time they issue a report, and if every major relevant scientific body agrees, that ought to be enough. Yet the public remains unconvinced.

Craven decides to look at both teams in detail. He cuts the denialists every inch of slack he can come up with, and they still come up wanting in the trustworthiness department.

That is a great service. (To be sure, he encourages the reader to make their own evaluation.)

All of which brings me to my biggest disagreement with Greg Craven. This is a book out of left field, and so it has statements here and there that strike the climate geek as bizarre, but they are minor points, and I don't feel a need to quibble.

We do have a point of disagreement. Greg says you should check your own conscience for "what would make you change your mind"? He says that if you can;t come up with anything, if that slot is empty, then your mind is closed and that's a red flag for incorrect thinking. But I have argued something that sounds pretty much like exactly the opposite!

But I have a complex and elaborate coherence structure to draw upon.

Consider how I got mixed up with the Klotzbach paper. Prominent naysayer Joe d'Aleo's blog alleged that most warming on land was due to a bias in the land surface temperature record, referring to Klotzbach's paper. Klotzbach's claim was not consistent with my coherence network. Therefore, I resolved to figure out what the unclear claim really amounted to. The deeper I got into it, the stranger it got. Eventually, one of the authors was compelled to admit that the word "bias" did not actually indicate an error in temperature. Further reading revealed many other flaws in the work, although the key one, which appears to have been reported (somewhat at second hand) by James Annan, is something I still don't entirely understand.

This is where the first principle cuts in. Should I further investigate the key claim, still contested by the authors? Well, I know James to be an extraordinarily careful and precise thinker, and it's already demonstrated that his opposition is not. Since boundary layer meteorology is not my forte, and since the rest of the paper is flawed in many ways, I feel satisfied that it's best to put my attentions elsewhere.

The main point for present purposes is that I immediately questioned the result claimed by d'Aleo on the basis of its incoherence with everything else I know. And my questioning turned out to be justified. The publication, though it passed peer review, probably should not have done so. It looks like science from a distance, but up close it looks like nonsense.

It's interesting that the article which violates Craven's principle is one which won me something of a convert. My old college buddy King of the Road, who arrived on this site a skeptic, was not won over by the strength of detailed argument, but by the appeal to coherence. Having a rich enough body of knowledge of his own, he understands how certain claims can be dismissed as nonsense, while others remain within the spehre of possible sense. So while Craven's advice regarding openmindedness is good for people who don't have a richly developed sense of intellectual coherence, it's not good for those of us who, um, have a sufficient body of actual knowledge.

But this is, in fact, consistent with Craven's other point. Which is to trust the geeks. (Some of whom actually are hippies, but that's another story for another time.) Why trust us? Not because we play chess better than you do while you dance better than us. Nor, even, because we really ultimately know what's what.

Trust us because we know what's NOT what. Trust us because we know when something someone says is incoherent with what we already know.

In summary, Craven's book is not enormously interesting to a scientist or science enthusiast. I would not recommend it directly to most of my readers, but we are not its target audience. It does not draw upon mathematical or physical coherence.

It just says, c'mon, it's obvious, this gang is the guys who know what they're talking about. They're not guaranteed to be right, but you're asking me to make a pretty huge bet that they are for sure certainly wrong. Why would I do that?

And that, in a nutshell, is the whole story told the right way. This is the book to give an earnest skeptical high school student, or a busy and disengaged adult. Craven has done us an enormous service in finding a way to address these audiences.


Scruffy Dan said...

well that justs about settles it, I am going to have read this book, in the hopes that it provides some good techniques for reaching out to the skeptics (deniers are beyond hope).

But this means that my readings in response to this paper: http://www.mathstat.uottawa.ca/~rsmith/Zombies.pdf are going to have to wait... grrrr

Anonymous said...

Michael, your honesty and ability to express your complex thought processes clearly makes this blog the greatest. Simplified, but not too much.

Unfortunately, articles like this are also very easy material for those who want to intentionally distort and misunderstand them.

The whole Galileo fallacy is the obvious one. Most stories, from ancient fables to present day movies are about the underdog overturning the establishment.

I think there really is a danger of groupthink and all those traditional "keeping your established advantageous position regardless of the facts" phenomena in science, but it's much less nowadays than before.

What was important with Galileo was not that he claimed something that was anti-establishment - it was that he was right in the factual sense.

We are also humans and sometimes want to stay in our comfort zone, and can dismiss things that are not familiar to us.

For example, US space policy is really really hard to discuss about without people (and this means enthusiasts who actually should know a lot) assuming that NASA must build some heavy lift vehicles, if any humans are to be sent beyond low earth orbit. That assumption is not rational, yet almost everyone is holding it. From the open Augustine panel of very highly skilled space professionals, only one really understood it as a fallacy, and maybe got a few others to question it. Most people didn't even understand to question. Some moved to an intermediate position of "some heavy lift vehicle is mandatory, not necessarily built by NASA", still an irrational position.
This all doesn't mean that a heavy lifter can not do the job. It's just that doing multiple launches has never gotten a fair chance in an architecture analysis. In the last studies, it was dismissed on completely false grounds.

So, when you talk to space professionals, some of them "get it" immediately, that hey, you don't actually *necessarily* need a heavy lifter. They might even know some of the history of thoughts behind orbital assembly etc, dating back to von Braun, before Apollo. But a large portion are just "that can never be done" - right in your face. It's outside their comfort zone - and they make an irrational claim because of that. Unable to question their own assumptions.

When a journalist is writing a story on propellant depots (the enabler for multi launch scenarios), he might get NASA to say something, to which the official might blurt something totally idiotic, like "if you increase the number of launches, you increase the loss of mission probability". Not so if you have propellant launch spares - you can actually decrease it. (Spares can be had since propellant launch time is noncritical and the spacecraft are possibly not expensive.)

This is why things require a rational analysis, and just nonfamiliarity is not enough to dismiss them. People can say "I don't know about that" or "I'm not familiar with that", and I'm okay with it, and even better is that "Sounds similar to X, that doesn't work for reason Y" that starts up to a reasonable discussion on the possible differences.

And then there's the class of stuff that the expert is very familiar with that doesn't work for rational reasons: perpetual motion machines etc.

And then there's the incoherence thing to add to it. You don't need to explore all the minute details of a proposition if it is rationally incoherent for the major parts.

What would make me believe in a lower climate sensitivity? I guess some new data. The DSCOVR albedo sat?
The GCR (cosmic ray) thing seems to me very very unlikely, but it's at least a logically proposed mechanism, ie it's not a traditional denialist illogical argument that collapses on itself, like the "warming before CO2".

Bryan Lawrence said...

Great review. I'll recommend it. But I figure "the deniers" will argue that coherence denies the possibility that some bright spark will be a "climate Einstein" with a game breaking theory. But we need to be ready to argue that Einstein (or Dirac or ...) didn't break the game, they extended it consistent with what was known. And underneath all the turtles, this is physics, not stamp collecting. (Don't give me Galileo you naysayer, we can deal with that one too!)

Arthur said...

On the issue of trust, I happened across this NewScientist article by Mark van Vugt this morning, updating some of the "Tragedy of the Commons" ideas.

van Vugt points to 4 i's as critical for handling "commons"-type resource problems (including climate change): "information, identity, institutions and incentives" - relating respectively to the 4 basic human motives in decision-making of "understanding, belonging, trusting and self-enhancing".

In the climate context, lack of understanding through lack of having absorbed the basic information about climate change and its impacts (including local ones) is clearly one piece of the puzzle. And a good part of that depends on the level of trust, or lack thereof, people have in the various institutions, organizations, or other sources of information out there.

Craven's book sounds like it can have significant impact for the average person's level of trust in scientific institutions, so that's a good thing.

And then there are the "identity" and "incentives" pieces. I suspect there are a lot of identity/belonging issues behind many people's support for "skeptics", despite any reason they might have to trust scientists or information they have on the issues.

van Vugt ends with:
"I would like ingenious conservationists, policy-makers, marketers and others to start using the 4i framework to influence the way people behave."

Dano said...

And a good part of that depends on the level of trust, or lack thereof, people have in the various institutions, organizations, or other sources of information out there.

This gets at how the op-eds are written, as I've mentioned before. Almost always, one can find in a vested interest op-ed the beginning has a little story. Why? This gets the reader's head nodding 'yes'. This head-nodding is the first element of 'trust'. When you trust the author, you are ready to receive the message.



(word verif says 'nesses').

Aaron said...

How much of a climate geek’s coherence model is correct, and how much is simply “not wrong?”

Climate science carries the baggage that it was developed by guys with interests in atmospheric science and rocketry. And, while we think of global warming as radiation interacting with gases in the atmosphere, most of the system is water. Seventy percent of Earth’s surface area is water. Most of the planet’s heat capacity is in its water. Much of the planet’s available carbon is in or under that water. And water vapor is a powerful feedback green house gas.

Two real impediments to our understanding global warming is that it is easier to take air temperature measures on land than out on the oceans, and it is easier to measure the temperature of various layers in the atmosphere than it is to measure heat in the depths of the oceans. Thus, our geeky coherence models tend to emphasize air temperatures over land. That just does not reflect the reality that most of the system is water. The geeky coherence model not wrong based on available data, it just does reflect the entire system.

While climate geeks have endless discussions over the temperature of this volume of air or that layer of air; the entire atmosphere holds very little heat at any given time. If the system was just radiation in air and land, we would have all the answers and there would be nothing to talk about. However, climate geeks have a bias and tend to say little about the great volumes of water that absorb, hold, and transport huge amounts of heat and GHG.

It is the inertias (thermal and chemical) of the oceans that make it hard to estimate the current state of global warming. It is the inertias of the oceans that make global warming a very long term problem. It is the feedbacks (including SLR) and biology of the oceans that make global warming an urgent and difficult problem. So, why don’t climate geeks spend 70% of their time talking about the heat and carbon in the oceans?

Michael Tobis said...

Aaron, I don't think you have a correct model of the science. Physical climatology is probably more about the ocean than about the atmosphere.

Most of the impact is the surface temperature on land and preciptation over land, so that is what gets the attention in the political, journalistic, economics, and impacts communities. No physical climatologist misses the fact that the dynamics on time scales over a few weeks is about oceanography.

As for the carbon, that's more complex. Land, air and ocean play roughly equal roles on decade to century time scales, though on millenial time scales the ocean dominates, and on very long time scales you need to account for geological processes.

In general, questions like "why doesn't the profession do X?" from people outside the given profession has one of three answers: A) we already do X B) X makes no sense or C) we'd like to do X but it's more difficult than it sounds. Very rarely is the answer D) huh?

Which is why I am so baffled about economics. I pretty much always get a D from them. Go figure.

Climatology, being broadly interdisciplinary, may lack rigor but it isn't likely to miss broad brush questions. You can't really judge this from what the press, even the pop science press, finds interesting.

I don't know about the "rocketry" idea in our intellectual coalition.

I think physical climatology is roughly defined as the union of oceanography and atmospheric science. While I was in grad school there, the U Wisconsin - Madison department changed its name from "meteorology" to "atmospheric and oceanic sciences", (was MET, became AOS) much to the chagrin of the weather nerds. That was some considerable time ago.

Marion Delgado said...

Mr. Tobis, did you see the exchange between Lucia and Tamino? I think that relates to this.

Michael Tobis said...

No, where?

Unknown said...

The whole concept of "trust" is interesting in this context. I looked in vain for the word "confidence" in the post, but trust ultimately means having confidence in someone. And I think that after nearly two decades of AGW debate, the public's confidence in climate scientists has broken down.

The problem is a mismatch between the climate science warnings and what the public see in the real world. I've raised this sort of topic before and been barely tolerated, so I'll try not to be too contentious. But anyone from the general public eyeballing, say, the satellite global temperatures would tell you immediately that the world hasn't been warming this decade. That's the general perception, in the UK at least, because real world experience doesn't match what we're being told. After three years of what is now widely seen as politically-inspired seasonal forecasting that has gone disastrously wrong, the Met Office is a national joke, and they have been guilty of some of the worst AGW alarmism. You would be very hard pressed to find anyone with any confidence in the Met Office. In the public perception, Met Office equates to AGW alarmism, so how can we trust these guys regarding climate change?

(The Met Office in the person of Dr Vicky Pope did try to back off from some its worst excesses earlier this year, but the damage was already done.)

The situation may be diffeent in the US, but I've read that opinion polls don't show a very high trust or confidence in climate science.

According to the definitions, Trust also has connotations of faith, and this book seems aimed at those whose faith is wavering. You say that it's not aimed at the "scientist or science enthusiast" so I suppose that means the great mass of the general public. But faith has to have something inspiring about it, and that inspiration seems to be sadly lacking at present.

And when the book's thrust is "... c'mon, it's obvious, this gang is the guys who know what they're talking about", I'm afraid that will only raise a hollow laugh, in this locality at least.

You may think I've lowered the level of argument to rock bottom, but that's where the battle has to be won. Not with the people who read RC (the keeper of the faith) or blogs like this, but with the great mass of poor benighted taxpayers. Climate science has to earn their trust.

bi -- International Journal of Inactivism said...


Whom do you trust then? For what reason do you trust those people whom you trust?

* * *

You say: "That's the general perception, in the UK at least, because real world experience doesn't match what we're being told."

Where did you read that from, and why did you trust what you read?

* * *

You say: "In the public perception, Met Office equates to AGW alarmism"

What gave you the confidence to make these grand pronouncements on "the public perception"? Whom did you get your ideas on "the public perception" from? Why did you trust them?

* * *

"I've read that opinion polls don't show a very high trust or confidence in climate science."

Which sources did you read that from? Why did you trust those sources?

These are questions you should think about.

-- bi

Unknown said...

bi-IJI: What or whom I trust is irrelevant to this thread - I've publicly declared myself agnostic here on this forum, because I believe we're still largely ignorant about extremely important parts of climate science, so I trust neither pro-AGW or anti-AGW advocates.

However, what is relevant to this discussion is what the electorate believes or trusts. The book makes out a case for trusting climate scientists. My point was that, here in the UK, that's unattainable - at present.

Why do I believe that? Vox pop, the voice of the people. It's what I read in the press, it's what I hear on news broadcasts, it's what I hear on the streets, it's what I hear (loudly) in bars and pubs. Do I trust those opinionated people or organizations individually? Gosh, no! But do I trust my own ability to make an informed weighting of public opinion? Yes, actually I do. Most reasonably intelligent people can. It's only the truly agenda-driven who ignore the shifts in the CoG of public opinion.

When organizations like the BBC (the BBC!) start poking gentle fun at the Met Office, that gets people's attention.

As for US opinion polls, you're right. I don't know how I can trust them. Out of my orbit. I'll stick to my own country!

Michael Tobis said...

"I'm an agnostic" is not necessarily credible itself.

As long as one carries water for the denial camp, repeating their talking points, dismissing counterarguments, a professed neutrality can be merely a tactic of a deliberate provocateur, or at best stigma of someone about to fall into their orbit. If what your write serves the purposes of advocacy of untruth, it's hard not to treat you as an advocate for untruth.

Regarding the "no warming over the past decade", as has been explained presumably everywhere you raised it, this is simply cherry-picking. In 1990 we heard a lot of "no warming in the past 50 years" nonsense, since 1940 had been a very hot year. Well, 1940 is long surpassed, but 1998 was a very hot year. So while that is roughly a decade we will be subject to the cherry pick.

As for the seasonal forecasts, I haven;t heard that one for a long time. It might be worth a thread of its own. But in short, it's the Bill Grays and Klotzbachs of the world that do that stuff. Frankly, I wish they'd stop. As climate change accelerates, their heuristics will become less and less valuable, and there is more and more need to appeal to physics. Which is what we are doing.

As for credibility, there's this. Separating climatology from science is trickery. It's the opinion of the entire scientific community that is at issue.

If you want to be treated as neutral, how about a balancing statement of some sort. Such as the one concluding this essay: "They're not guaranteed to be right, but you're asking me to make a pretty huge bet that they are for sure certainly wrong. Why would I do that?"

Unknown said...

Gosh, I thought I couldn't be clearer, but I guess I was wrong.

These are not my arguments! My opinion is irrelevant here. The only reason I repeated them here (in a thread on the topic of Trust) was to show simply that public opinion tends to run runs directly counter to the idea of trusting those who're "entrusted" to set a lead in the AGW debate. As I wrote above, I trust my ability to weigh public opinion.

I'm sorry to belabour the point, because I really don't want to raise hackles here, but pointing out statistical subtleties of temperature records is pointless in the context of the general population. It's not me you need to convince ... it's the vast majority who don't read scientific papers or blogs. They pick up their views from the media and their own observation of real life. And real life hasn't been kind to the AGW story (remember, that's not my opinion!)

I know I'm repeating myself, and I apologize, but climate science has to come up with a narrative that people can trust. The Met office, for one, has let them down badly in this respect - climate-wise, not just seasonally.

And please don't accuse me of being a denialist. You may not like the message, but my simply stating the facts of life - at least, as they generally apply here - does not make me a denialist. It makes me a realist.

Michael, I know I'm here on sufferance, and I don't want to make you suffer too much! If you'd prefer, I'll happily bow out from the discussion at this point.

bi -- International Journal of Inactivism said...


"Vox pop, the voice of the people. It's what I read in the press, it's what I hear on news broadcasts"

Are you saying that "the press" and "news broadcasts" say that global warming isn't a problem? In that case, why do you trust that whatever the reporters or news anchors say is the same as "public opinion"?

Or are you saying that "the press" and "news broadcasts" report that other people think global warming isn't a problem? In that case, why do you trust that they're accurately reporting "public opinion"?

Either way, why do you trust them?

* * *

"it's what I hear on the streets, it's what I hear (loudly) in bars and pubs."

You know, certain groups of people simply talk louder than others. But being louder doesn't mean that there are more of them.

-- bi

Anonymous said...

These are not your opinions or assertions? Excuse me.

For example snowless winters, migration patterns (earlier arrivals), new pests, new diseases (mites carrying some nasty things for example), etc etc... all happening here in northern Europe.

Strange how I experience some of that first hand and read a lot about some of that and you don't. Do we live in a different world? Or do we prefer to read different sources of information?

guthrie said...

Having spent a number of years in the trenches, I think I can sum up the general opinion of people quite clearly.

1) Climate change? Duhhh, whats that?
2) Climate change is a clear and present danger
3) Climate chance is made up by greenies/ the gvt/ the UN in order to raise taxes/ take away our cars/ take us back to the stone age.
4) Climate change , I read about there being something wrong but excuse me, I've got to go and pick my kids up from school then go check on my aged mother.

Group 3 is by far the loudest, although group 2 is usually given precedence in news reports.

When you look more closely at group 3, the usual problem is that they have an a priori commitment to something which will have to be changed in order to combat climate change. Whether this is cars, taxes or whatever, it clouds their judgement so they make lots of nonsensical claims, which I have played my part in demonstrating to be wrong. But when someone is being stupid, no amount of evidence will persuade them otherwise.

Your average person in category 4 simply doesn't listen or doesn't have time to go through the science, and at the level of gvt action is irrelevant. We have many organisations from FotE to local action groups trying to get support going on a local level, with some success. Meanwhile councils and others are trying to integrate carbon footprint stuff into their jobs.

So, what I'm getting towards, is that Alex is partially correct, but also misses the nuances of the situation. In actual fact we have enough people and institutions persuaded already; the residual moaning is somewhat like that about the NHS, only the hard core bastards want to get rid of it, everyone else just wants it to work better. So it is with climate chance, most people won't even notice the earlier changes brought in to deal with climate change, and they are uncertain simply because of the lies spread by people from Christopher Booker to Ian PLimer.

Michael Tobis said...

Other than seeing not much distinction between groups 1 and 4, guthrie seems about right. On the other hand, you have to give group 3 credit (well, OK, blame) for for having done considerable damage in the past and for making a credible effort toward doing more in the future.

Anonymous said...


You make a strong argument, but perhaps a tad too strong:
“Basically "what do you believe" comes down to a question of "who do you trust". (…)
By trust, and trust alone.” I think there’s more than trust alone.

I think you’re entirely correct that a consensus amongst relevant experts ought to be enough for the public to gauge the value of certain claims. But there are more clues that could help in distinguishing the chaff from the grain. See e.g. my list of clues for laypersons to decide on what to believe:

Seeing the forest for the trees
Consensus matters
Beware of conspiracy theories
Spatial scales
Confusion of cause and effect
Think in terms of likelihood
Think in terms of risk

Granted, about a quarter of these directly relate to the question on who to trust, but most stand by themselves. E.g. some illogical or incoherent statements (that are nevertheless often heard) don’t require any background knowledge to see through. Btw, I think Craven did tremendously good work with his videos in reaching people that blogging scientists will never reach.


Unknown said...

Yes, I'd largely agree with guthrie, but he seems to have missed the group with which I'm probably most familiar, because they're my peer group. That's the group (let's call it group 5) that reads what it can in the non-specialist literature, and has a serviceable and wide understanding of science at a high level. This group has either decided that the A in AGW is not true, or (like me) the science is far from settled and it's not an intellectually honest position to declare for one side or the other. Of course, some of group 5 have joined group 3 already.

It's interesting to speculate on the population of group 3 and, as I got criticized for ducking numbers before, I'll guess that it's around 15-20% of the general publication. And I bet it's a lot less than Group 5. Do I trust that? No! But it's a long way from a majority in an electorate, when economically tough decisions have to be made.

Michael, this is OT, but it might be interesting to have a thread on the subject of intellectual honesty in a scientific context. Various people in this forum seem to think that "if you're not 100% with us, you're against us." And that's a ludicrous position. Look at the example of Richard Dawkins - we all know his position on religion, but he's honest enough to say in his book that on a scale of 1-7 for the probability of a deity existing (7 = 0%), he places himself at 6. Yet so many pro-AGW people appear unable to accept the position that less than 100% belief is posssible without making oneself a "denialist".

I've listed reasons for being less than 100% certain here before, including the areas that are still largely unknown. For example, the CLOUD experiment shows that a lot of very clever people at CERN believe there's a lot more to learn about the atmosphere/sun interaction, and unless you're prepared to trust your own judgement more than CERN's there is obviously an area of uncertainty. CERN would not spend millions or billions of dollars if this was not an important question.

Then, if you can bring yourself to admit areas of uncertainty, then you should admit the possibility that there will be people - yes, including me - who are not denialists but, like Richard Dawkins, know that that there are gaps in our knowledge.

Yes, I know RD is fairly comfortable in his atheism, but he's intellectually honest. And we need strict intellectual honesty in the scientific and political worlds if our decisions - shaped largely by areas of ignorance - lead us down economically perilous paths.

If this post makes just a few people think carefully about their position, it will have been worth it, even if they don't change. I'm not confident that we'll get close to intelelctual honesty in this field for some years ... and I'll trust my own judgement on that!

Unknown said...

PS ... I rashly claimed in my last post that Group 5 is probably bigger than Group 3. I withdraw that unreservedly, as I have no means of judging that.

guthrie said...

Yes, I should have been more clear on group 4, (i did just make these categories up on the spur of the moment) I meant it to include the people who have installed low energy lightbulbs and do put out their recycling bins but don't necessarily know much about the topic, whereas group one is those who are disconnected from the wider world and sit watching entertainment TV all day.

And 15 to 20% of general population for group 3 sounds ok.

Group 5 - ahh, well, that is a debate right in itself.
"That's the group (let's call it group 5) that reads what it can in the non-specialist literature, and has a serviceable and wide understanding of science at a high level"

You see, a wide understanding of the science of climate change at a high level is completely absent from the majority of complaints that people make. From Courtney to Plimer to those who wrote in and complained a few weeks ago after that American science magazine, I forget exactly which, did an editorial on AGW.

Michael Tobis said...

Alex, two points.

First you have to state the proposition before I can state the associated certainty. "AGW" is not a proposition.

Is it that "CO2 is a greenhouse gas"? My certainty is over 99.99% even though I have never done the experiment.

Is it that "business as usual on emissions would lead to extremely dangerous climate outcomes within this century"? I'd say somewhere between 80% and 99%, depending which day you catch me. And this is the real policy-relevant question, which I proceed to address here.

(Also there's that unfortunate thing about murdering the oceans, completely independent of climate change. Put me down for another 80% chance of disaster for that.)

In order to justify inaction, though, you need to put the likelihood at about, what, 5% or less?

That's the second point. Are you really 95% sure that the inactivists' much balyhooed confusion is more valid than the considered opinion of the entire scientific community? As represented by the G8+5 science academies, the AMS, the AGU, the APS, and so on? Or are the people to whom you refer so sure?

And can you or they be so sure, if we really have so little idea of what is going on, that the sensitivity is going to be much smaller, not larger, not even somewhat smaller, but much smaller, than the great preponderance of the evidence?

Including Tamino's simple, straightforward analysis of the analysis that you could do on a pocket calculator?

I admit that engineers and dentists get this wrong in alarming numbers. That's a key concern.

This is the crucial piece of the argument from Craven's point of view. If one goes against the scientific community when the stakes are so high, one needs extraordinary certainty, not just uncertainty and confusion. Otherwise the position is deeply irrational. And the fact that engineers and dentists come to deeply irrational opinions about this matter is very disturbing.

Michael Tobis said...

Bert, I agree with your list. Craven does not get into that at all, indeed he bends over backwards to treat the denial literature as equal in legitimacy. Still his plate is still full in the book.

There is a second book to be written about the points you raise. I am not sure Greg is up to it; somehow it doesn't suit his style.

the_heat_is_on said...

The Galileo fallacy is popular with the libertarian worldview. This worldview presents the scientist as a maverick working in his basement and trying to expose the "corrupt consensus". This pattern is seen in Atlas Shrugged and State of Fear.

"So how should a kid (or an adult!) who is honest enough not to just go with his or her crowd, who wants to get to the right side of what is obviously an enormously important substantive question, evaluate the competing arguments?

By trust, and trust alone. That's the only way to do it."

John Quiggin:
"As far as the relevant scientific communities are concerned the controversy over evolution has ended and the controversy about climate change has resolved most of the key issues (for example, that warming is taking place and that human activity is a contributor), as has the controversy about the safety of consuming GM foods, but that doesn’t stop people claiming otherwise. And the tobacco lobby only retreated from the glaringly false claim that smoking is harmless to the claim (absurd if you accept that direct smoking causes cancer, but harder to disprove) that passive smoking is harmless. Unless you want to become an expert in biology, geology, climate science, clinical medicine and statisics, among other disciplines, you’ll never be able to resolve these disputes without relying, at some point, on expert judgement.

Obviously, there’s an element of circularity here. We not only have to trust scientists to give us the best advice, but we also have to trust them to tell us who the relevant scientists are. The big argument for accepting this is the undeniable success of the scientific enterprise as a whole, and its demonstrated capacity for correcting error. This can be contrasted with the demonstrated capacity of interest groups to maintain propositions that suit their interests in the face of strong, indeed overwhelming, evidence to the contrary."

This is the problem of MSM: failure to recognize expertise and scientific authority. Of course, it's cheaper to engage in "he said X,she said Y" journalism than looking into bibliometrics or doing real investigative journalism.

King of the Road said...


Condescension and disingenuousness is a bad combination. In my opinion, it is not possible to be a non-specialist, but have a "serviceable and wide understanding of science at a high level" and not find Michael's argument on what it would take to falsify his belief in warming to be compelling.

It would be like saying "I have a serviceable and wide understanding of science but your arguments against perpetual motion are unconvincing. What absolute proof do you have of of the second law of thermodynamics? Can you derive it from first principles? How do you explain so and so's overunity device?"

Therefore, I infer that you are actually in what I'd call group 3a - a denier feigning open-mindedness. On a blog comment list, I think this is known as a "concern troll."

Unknown said...

Yes, good points, Michael. I'd thought, in my loose non-scientific way, that the question was equivalent to the simple one about the existence of God: is Humankind solely responsible for global warming? But because I hope that we can all accept that there are some natural cycles involved, your rephrasing is much closer to what I now think it should be: "business as usual on emissions would lead to extremely dangerous climate outcomes within this century."

And I like the phrase you used about your own feelings ("depending which day you catch me") because that's close to how I feel. But my certainty range is different than yours: it's, say, 20-50%.

How could we converge on this? The IPCC lists areas of uncertainties, but generally dismisses them (I think - it's a while since I looked.) Presumably, deep within the IPCC, there must be an analysis of the risk factors associated with each of the areas of uncertainty. And if that analysis could be made open and transparent and subject to public scientific scrutiny in relation to the climate computer models, then at least a good scientific debate would start. Because the old assertion that the "science is settled" is sweeping big things under the carpet.

If I'm right about the complete absence of debate about the uncertain areas in relation to the models, then it's hardly surprising that the G8+5 signatories can all sign up. It's easy for them to ignore the twinges of conscience for suppressing intellectual honesty.

But are you sure that even the G8+5 is as unanimous as it first appears? I see Germany is a signatory, yet 130+ prominent German scientists (I quote from the news) wrote to Chancellor Merkel urging her to “strongly reconsider” her position on global warming and review the latest climate science developments. The signatories include IPCC scientists.

Do I trust that story? About 95%, probably. And of course there are obviously others that I could quote (like the APS that you cite.) But to pick up on your point about Tamino's analysis, I think that the debate in Lucia's blog has confirmed my instant presumption that he has just reworked the existing model assumptions ... anyway, it doesn't seem to be as clear as Tamino would like us to think.

You rightly say that to go " ... against the scientific community when the stakes are so high, one needs extraordinary certainty, not just uncertainty and confusion." I certainly don't have that certainty, but I sincerely want to see open debate that would reduce uncertainty and confusion.

My upper range of 50% is not hugely different than your lower range of 80% - should be bridgeable anyway. And if we settled on, say, 60% would you still be committed to economically perilous courses of action?

Unknown said...

To Mr "King of the Road": labeling a poster is the standard response of the committed pro-AGW lobby when they don't like what they hear, but can't rebut it.

Try making some relevant points about areas of uncertainty. Try adding your own degree of certainty about the proposition that Michael outlined and I addressed, and then justify your position. Try making some sensible suggestions about closing the gap between true believers and the intellectually honest who don't have enough faith in the completeness of the story.

Then, perhaps, you might be entitled to style yourself King of the Road. Simply denigrating me with a label is not exactly regal behavior.

Michael Tobis said...

Alex, your model of "extremely dangerous" must be different from mine. I mean causing or contributing to a catastrophic increase in global mortality leading to a rapid population decline, probably manifesting as war and anarchy.

You probably mean "costing a few per cent of GDP". Talk about economic peril strikes me as ridiculous. This simply isn't about money.

It's the difference between an amputation and a haircut. An economy will grow back. You're squawking about not treating your massively infected leg because you don't want to miss your barber's appointment.

To put it another way, a planet will get you through times of no money better than money will get you through times of no planet.

The real category error is this: Economics is the instrument of policy, not its driver. Economics should be construed as an engineering discipline, not as a science.

King of the Road said...


It's irrelevant what I may label you. The point is that I don't believe you. Neither you nor I are currently or able and willing to develop expert levels of knowledge in any pertinent field. Therefore we have to decide what "makes sense" and to who actually does have the relevant expertise.

I claim that your statement regarding a serviceable and wide understanding of science at a high level is false based on the evidence you have presented. It may be that you believe it, if so you are wrong. It may be that you don't believe it, in that case you are disingenuous.

This is not a discussion about the molecular pathways for a particular obscure chemical process or the aerodynamic behavior of a fairing on a hypersonic airfoil. Such a discussion would, in fact, revolve around small arguable details, and at the moment, the experts just may not know.

This is a discussion about many well-understood areas of science coalescing around a conclusion. With which broad area (thermodynamics, fluid dynamics, radiation physics, statistical analysis, etc.) do you find fault?

No one that I've read claims that 100% of the warming trend is caused by man made emissions of greenhouse gasses. Implying that climate scientists say so and that it can't be proven that other factors may not be at work is a straw man.

It's clear that there are gaps in our knowledge of the behavior of the geophysical system, scientists are working to fill in these gaps. The same can be said of our knowledge of quantum mechanics, but that doesn't mean that scanning electron microscopes, magnetic resonance imagers, and Josephson Junctions may not work.

Anonymous said...

"Sure enough, when you actually start counting, the number of naysayers turns out to be, well, puny."

I believe it was Joe Romm who said that skeptical scientists "remain a group small enough to fit into a typical home bathroom."

Anonymous said...

"Yes, good points, Michael. I'd thought, in my loose non-scientific way, that the question was equivalent to the simple one about the existence of God: is Humankind solely responsible for global warming? But because I hope that we can all accept that there are some natural cycles involved, your rephrasing is much closer to what I now think it should be: "business as usual on emissions would lead to extremely dangerous climate outcomes within this century.""

Note that the existence of god (as most currently view it), is not a question of science and evidence. Global warming is.

Let's use a stupid example: retreating to an "agnostic" position in the question, is the Earth closer to a pancake or a sphere in shape, is either ignorance or lunacy, because nowadays so much evidence points to the quite spherical shape. Saying "I don't think the matter is certain" can actually be very very irresponsible and much less careful than saying something specific.

Anthropogenic global warming is of course a more complicated and less directly observable thing, but nevertheless there is a lot of evidence, and I've seen very few other coherent models explaining it. I'm no expert, but for my engineer's mind, the model is very plausible.

Some oversimplified models presented in high school and in popular science were very impossible by the way, to someone who knew basic physics and mathematics back then. Why are the rays going one way but suddenly blocked going the other way? I think an improvement in this regard is very very much required. The goal is not to make people believe - it is to make them *understand*. When a significant percentage of the population understands the basic mechanism, they can not be swayed by those whose primary way to deal with things is to deliberately misunderstand. This is true with evolution through random mutations and natural selection or the basic CO2 greenhouse effect by letting through visible light but absorbing heat radiation.

Very simple, very powerful ideas.

Our physics teacher used the Socratic method. We could ponder some problems for an hour, and people would suggest theories and solutions, and the unworkable ones would be shot down since they would show up not working upon closer examination. In the end, we would end up with how things are - and in mathematics, how they actually must be, given the assumptions. Mathematics is beautiful that way. I remember how even some of the usually less mathematically confident students in the class understood and explained some up to that point new concepts - how they must be like that and can not be in some other way.

It takes time and curious minds though.

Martin Vermeer said...

I think that the debate in Lucia's blog has confirmed my instant presumption that he has just reworked the existing model assumptions ... anyway, it doesn't seem to be as clear as Tamino would like us to think.

This is what I would call "peephole credibility"... or lack of same. I happen to have on this matter the "serviceable and wide understanding of science at a high level" that you claim to have but are lacking. I actually produced Tamino's derivation independently a few years ago for my students. It's 100% correct. If you take Lucia seriously on this, you have problems mate.

Michael Tobis said...

Alex hrrmphed "Then, perhaps, you might be entitled to style yourself King of the Road. "

Not much on cultural references either, are you?

guthrie said...

Lets do this line by line, because I'm faffing about.

"The IPCC lists areas of uncertainties, but generally dismisses them (I think - it's a while since I looked.)"

It quantified them quite clearly in a number of charts. It also lists the various things affecting climate, not just CO2 but other gases, land use changes, albedo, etc etc.

"deep within the IPCC"
You mean within the scientific papers references by the IPCC. Its all there, in the report, if you care to look.

"risk factors associated with each of the areas of uncertainty"
That in itself would probably require anotehr report in itself. Please contact your local gvt to persuade them to carry one out. The UK gvt got Stern to do a review, although you may disagree if it covers what you wanted it to cover.

"If I'm right about the complete absence of debate about the uncertain areas in relation to the models"

You mean all these scientific papers and debates at conferences aren't enough? You've presumably missed all the discussion about how models don't match observations precisely, and vice versa? Which planet are you on?

"But are you sure that even the G8+5 is as unanimous as it first appears? I see Germany is a signatory, yet 130+ prominent German scientists (I quote from the news) wrote to Chancellor Merkel urging her to “strongly reconsider” her position on global warming and review the latest climate science developments. The signatories include IPCC scientists."
Firstly, you cannot conclude frmo a letter to a prime minister that a country itself, or its government, is at all shaky on AGW. Secondly, as we know the news media call everyone prominent, yet when you look here:
Its a mere 67 scientists, of whom 1, yes thats right, ONE, claims to have taken part in the TAR as a reviewer. That doesn't make them a climate expert, since you could become a reviewer if you asked.
Thirdly, it recycles the same tired old lies that we have answered many, many times before. If you do not see this, then I'm afraid you clearly don't have the knowledge you claim to have.

Unknown said...

OK guys, enough already. Don't shoot the messenger! I guess I should have expected that you wouldn't like my lack of cultural references (culture? really?), my claims to scientific understanding ("high" means 50,000' level, not in-depth) and so on.

In an earlier thread, I told you all my reasons for being an agnostic, listing the areas of uncertainty, and putting them into a narrative to show how why I couldn't feel confident in the AGW proposition. Not one of you could rebut it (or if you could, you remained very coy about it.) But instead I got a lot of snark, obviously.

So I feel I, at least, have some intellectual honesty in saying that I can't trust pro-AGW scientists. This is all about trust, right? Conversely, I can't trust anti-AGW scientists either. And I have to ask you to examine your own AGW intellectual foundations, and broaden your perspective. If you can't be bothered to go back and revisit what I said before, there's a single example in this thread for you to consider: why do you think CERN are investing huge amounts of money in the CLOUD experiment if "the science is settled"? That shows that there is a very large hole in our understanding, which doesn't show up in the GCMs or Tamino's little exercise. Again, no one has said that this experiment is a waste of time.

Please don't tell me I'm not as clever as I think (yes, I know that - I think) or I'm disingenuous, or that I've got the number of German scientists wrong (I'm right, it's 131, another 64 announced on Aug 09). These are all true-believer distractions.

Instead, simply tell me why I should ignore the large areas of uncertainty, and tell me why they're irrelevant. (I don't think anyone has today, but it might have got lost in a large amount of noise.) If you can, I'll genuinely review my position, and upgrade my assessment of climate disaster. If you can't, well, it's probably not worth you replying.

Michael Tobis said...

From a policy point of view, it is not enough to express a lack of confidence. To advocate inaction you have to express a very strong confidence that the sensitivity is much smaller than the consensus has it.

Yes there is much to discuss about the individual streams of evidence that lead to a sensitivity (specifically a Charney sensitivity) of 2.5 - 3 C per CO2 doubling. And there are multiple uncertainties involved.

But it's impossible to advocate for inaction without a much smaller sensitivity, say below 0.5 . So if you are equally uncertain about the consensus and the low-sensitivity gadflies (ignoring all high-sensitivity gadflies, of course), even that is plenty to support a vigorous carbon policy.

Essentially you are irrationally shifting the burden of proof.

If you want to talk science, we can talk science until you get bored of it. (You have already demonstrated in another thread that this happens very quickly.) But you don't you want to talk science. It;s clear you are not interested in science itself, but only in science as it impacts policy.

But the policy argument is not based on certainty that the consensus is right. It only needs a significant likelihood that either the consensus is right, OR that the potential for error is not especially one-sided.

The thing that makes you a concern troll in my view is not only that you question things you refuse to investigate, though that is problematic enough. It is that you are asking a policy related question, and yet make no effort to understand the fact-based reasoning behind that policy issues.

Even though it's key to the whole business, you don't care what the greenhouse gas sensitivity number is. You've already said so. Your indifference to quantitative arguments precludes any discussion of details. For you to turn around and accuse people of ducking questions is bizarre, when you show every intention of ducking the answers.

Look, even if you find nothing compelling on either "side", which is unfair because it counts gadflies on only one side, your risk matrix weighting has to be 50/50. But with a 50/50 risk weighting you still have nearly a 50% chance of globally catastrophic outcomes in the no-new-policy case.

Try to act rationally in agreement with your stated beliefs and we'll have no argument.

the_heat_is_on said...

"economically perilous courses of action"
Now tell me who's the alarmist?
Where's the evidence suggesting economic ruin if we adopt a thoughtful carbon policy?
Also, let me remind you that build-up of CO2 isn't an exclusive atmospheric problem. There's a little thing called ocean acidification.
Let's also remember that carbon-based energy sources are headed towards depletion and that coal has a huge environmental and health impact.

Unknown said...

Michael, Michael ... this thread is about trust. Remember? And you've done it again: as soon as the discussion gets uncomfortable or difficult to rebut, you change the ground, and ask for a number based on science (stricty yourunderstanding of the science) because that's in your comfort zone. It's probably best not to raise more philosophical subjects like trust in climate science if you're not comfortable with the answers.

The same goes for intellectual honesty. I raised the subject as an adjunct to trust, or as another thread ... and no one said it wasn't appropriate. Yet no one has addressed the topic in a meaningful way; what should I make of that?

But since you're determined to get something from me that will satisfy you, I'll tell you, so that you can have a good laugh, and mock me for my naivety.

You obviously go along with the IPCC range (or higher, given your apocalyptic visions). Yet this century the temperature has not climbed (no tired memes about tired memes, from anyone,please, so something is more than equalling (oppositely) the IPCC model forcing. I have no clue what it could be, but I'd hazard a guess that it's one of those areas of uncertainty you want to ignore.

In crude terms, that either means that the IPCC number is much less than estimated (because we don't know of anything else that could have that effect - yet) or there is another powerful and opposite feedback factor that we probably should be worrying about.

I think the first option is the more likely. And conveniently, the Lindzen and Choi paper gives me a likely sounding answer: 0.5C.

The paper has been available for a while, yet none of the usual suspects has rushed to demonstrate its fundamentally flawed assumptions. In fact, things are suspiciously quiet - there's a lot of head-scratching going on.

So there's my answer: 0.5C. Now, could we get back to trust? Do you trust Lindzen and Choi? Respected scientists both. And have you got the intellectual honesty to factor their findings into your thinking about AGW?

guthrie said...

I'm sure it was Richard Tol that said on a blog that changes in interest rates by gvts caused more economic losses than any sort of sensible scheme for dealing with global warming.
Certainly the chaos we have had over the last couple of years puts it all into perspective.

David B. Benson said...

Alex --- Current global warming is entirely anthropogenic in origin, except maybe a little due to currently low volcanism. Without human activities, the climate would be, on long term average, slowly cooling towards the next attempt at a stade (massive ice sheets) about 20,000 years from now.

For more on this, plase read climatologist W.F. Ruddiman's popular "Plows, Plagues and Petroleum". More can be learned by reading his papers, obtainable from his web site.

CERN's CLOUD experiment will settle a minor issue; the major players such as CO2 and water vapor have already been well studied. (Incidently, satellite data from two regions of the Pacfic Ocean appear to indicate that clouds are a small positive feedback; more warming, less low clouds.)

wonderingmind42 said...

Michael and all: Thanks for the review and discussion. I'm sorry I don't have time to be eloquent here. My two cents on the discussion: (part 1 of 2)

The battle is with the masses. With group 4. With soccer moms and NASCAR dads in "flyover country." In my experience in the popular debate in the last two years, I'm highly confident that any form of the argument "trust the scientists" (or policy makers, or whomever) will not succeed at the necessary rate. Libertarian/republican/pioneer/"Self Reliance" sentiment is too deeply ingrained in the national character of America. To be willing to make even perceived (but unreal) sacrifices, Joe Schmoe American will have to 1) stop feeling like he's being blamed as the bad guy, and 2) feel like *he's* making the decision, rather than handing over the power to some elitist intellectual (i.e. anybody with a degree higher than a Bachelor's, excepting MBA's and economists who tell him exactly what he wants to hear).

That ain't the way that it should be, but I'm quite sure that's the way it is. This is no longer the Generation who persevered through the Great Depression, or mounted the greatest economic mobilization in the history of the world to fight and win WWII. We will either speak on their level, or lose.

Some institutions are fighting the good fight, and change is happening at the normal rate of social change--punctuated linear. Unfortunately, seems to me that climate change may happen at a nonlinear rate. I fear that social change will not be sufficient to forestall possibly catastrophic and irreversible consequences. Instead I think we need to work to changing HOW social change happens.

My proposal (in the Appendix of the book) is to try to spark a non-linear social change (what Malcom Gladwell calls a "social epidemic") by designing and spreading memes which will self-propagate (hence needing no organizations, funding, or campaigning) and create a wholesale change in the culture, so that a policy maker can't turn around without having a knot of constituents in their face, saying "What are we--you--going to do about climate change?!?" To catch the nonlinear curve of climate change with a nonlinear curve of cultural change. I don't think it's ever happened before in history, but I fear that it may be our only hope for making the probability of catastrophe tolerably negligible. I hope I'm wrong about that. But I don't think any of us want to bet our family's futures on that hope.

I got the idea after my "Most Terrifying Video" went viral--7.2 million views for a 10-minute video of a whiteboard lecture on global warming. A proof of concept, if you will. The grid was my shot at a meme, and this book is my last, desperate attempt.

wonderingmind42 said...

(Part 2 of 2)
Even though it is not written for any of you (since you are not in group 4), I hope that you will find it a valuable tool in bringing about the end that you want. Because the fight lies with the masses. So please read it, remember that YOU are not the one it's trying to influence, but that you are powerful with it, because you can spread it to others who DO need it. That's part of how you ARE the target audience: to take this and run with it as fast and as far as you can, spreading the ideas to group 4. Because my publisher has hung me out to dry, and I've got nothing left in me to pursue the marketing myself. So I've got to leave it in your hands.

Read it. Then lobby other climate blogs, websites, and media sources to review it. Besides the two climate blogs "In It" and "ClimateSight," there is only one major review of it out there: Chris Mooney's in the "New Scientist." Everyone who's read it has found it valuable (so they tell me, and I count Michael because even though he didn't gush, he at least said he wasn't too unhappy to buy a replacement copy :-), but the bottom line is: no one knows yet that it exists.

Thanks for all the effort, energy, and thoughtfulness that you all put into the fight.

P.S. Michael--I can't tell you how affirming it was to discover a quote from me at the top of your blog. :-D I've been bragging all week!

Michael Tobis said...

Alex, Lindzen and Choi was published on Wednesday. Nobody besides Lindzen, Choi, and the GRL reviewers has much idea about it yet, The fact that Morano thinks it is important is completely predictable.

The fact that real scientists have not yet expressed an opinion either way may have something to do with intellectual honesty.

Michael Tobis said...


Thanks for coming by. I did mean my review as a rave, actually.

I'm a little confused as to what you are saying here, though, but hey, it's late. I'll think about it again some, later.

Anonymous said...

You touched the sore spot here: So far we're failing to reach Joe Schmoe (though I think you've done a great service on that front with your videos).
But are scientists the right people to do so? Isn't there's a fair bit of anti-intellectualism in small town America that make scientists pretty much unsuitable to reach out to them? I have no alternative directly, but the communication 2.0 idea (see the newest post here) perhaps has some promise: Put policies in place that demand a behavioral change. Because as you say, behavioral change by education and attitudal change go way to slow.


Anonymous said...

"Yet this century the temperature has not climbed so something is more than equalling (oppositely) the IPCC model forcing. I have no clue what it could be, but I'd hazard a guess that it's one of those areas of uncertainty you want to ignore."

This thing certainly suggests otherwise:

Or these:


1958-2009 CO2 rose to 1.24 fold. That's about 2^0.31, or roughly a third of the way to a doubling.

With a 3 C sensitivity to doubling, that would mean 0.93 C.

The temperature trend linear fit in GISS data is 0.6 C. Ie from that only, the sensitivity estimate could be 2 C per doubling.

There's some disrepancy in this first order rough estimate, between 2 C and 3 C, but at least it's of the same sign and magnitude. :)


Oh, this century meaning since 1999?
Well, it hasn't risen that much. http://woodfortrees.org/plot/gistemp/from:1999/trend/plot/hadcrut3gl/from:1999/trend/plot/uah/from:1999/trend/plot/rss/from:1999/trend



The trend does seem slightly positive, not negative. (You may mix up with the carefully timed "ten years" claims made in 2008; since 1998 was such a warm year, the global trend was probably low.)

That's the problem with looking at short time scales. The individual years vary quite a lot for various reasons, and dwarf the CO2 induced trend. There are solar cycles and ocean circulation variations for example.

I encourage people to play with that app, it's a great service!


I think you mix up "ignoring uncertainty" and "having enough certainty warranting acting".

But even that is just playing your game - as Michael explained, the thinking is fallacious on a broader level.

We are injecting large amounts of CO2 to the atmosphere. The amount is already larger than at any time during the holocene, the warm stable time when civilization developed, and you cannot justify it being safe just by saying that "we don't know what will happen".