Posts tagged ‘IPCC’

Climate Alarmism In One Statement: "Limited Evidence, High Agreement"

From James Delingpole:

The draft version of the report's Summary For Policymakers made the startling admission that the economic damage caused by "climate change" would be between 0.2 and 2 percent of global GDP - significantly less than the doomsday predictions made in the 2006 Stern report (which estimated the damage at between 5 and 20 percent of global GDP).

But this reduced estimate did not suit the alarmist narrative of several of the government delegations at the recent IPCC talks in Yokahama, Japan. Among them was the British one, comprising several members of the deep green Department of Energy and Climate Change (DECC), which insisted on doctoring this section of the Summary For Policymakers in order to exaggerate the potential for more serious economic damage.

"Losses are more likely than not to be greater, rather than smaller, than this range (limited evidence, high agreement)"

There was no evidence whatsoever in the body of the report to justify this statement.

I find it fascinating that there can be "high agreement" to a statement for which there is limited or no evidence.  Fortunately these are all self-proclaimed defenders of science or I might think this was purely a political statement.

Note that the most recent IPCC reports and new published studies on climate sensitivity tend to say that 1) warming in the next century will be 1-2C, not the much higher numbers previously forecast; 2)  That warming will not be particularly expensive to manage and mitigate and 3) we are increasingly less sure that warming is causing all sorts of negative knock-on effects like more hurricanes.  In other words, opinion is shifting to where science-based skeptics have been all along (since 2007 in my case).  No surprise or shame here.  What is shameful though is that as evidence points more and more to the lukewarmer skeptic position, we are still called evil heretical deniers that should be locked in jail.  Like telling Galileo, "you were right about that whole heliocentric thing but we still think you are evil for suggesting it."

Climate Humor from the New York Times

Though this is hilarious, I am pretty sure Thomas Lovejoy is serious when he writes

But the complete candor and transparency of the [IPCC] panel’s findings should be recognized and applauded. This is science sticking with the facts. It does not mean that global warming is not a problem; indeed it is a really big problem.

This is a howler.  Two quick examples.  First, every past IPCC report summary has had estimates for climate sensitivity, ie the amount of temperature increase they expect for a doubling of CO2 levels.  Coming into this IPCC report, emerging evidence from recent studies has been that the climate sensitivity is much lower than previous estimates.  So what did the "transparent" IPCC do?  They, for the first time, just left out the estimate rather than be forced to publish one that was lower than the last report.

The second example relates to the fact that temperatures have been flat over the last 15-17 years and as a result, every single climate model has overestimated temperatures.  By a lot. In a draft version, the IPCC created this chart (the red dots were added by Steve McIntyre after the chart was made as the new data came in).

figure-1-4-models-vs-observations-annotated (1)

 

This chart was consistent with a number of peer-reviewed studies that assessed the performance of climate models.  Well, this chart was a little too much "candor" for the transparent IPCC, so they replaced it with this chart in the final draft:

figure-1-4-final-models-vs-observations

 

What a mess!  They have made the area we want to look at between 1990 and the present really tiny, and then they have somehow shifted the forecast envelopes down on several of the past reports so that suddenly current measurements are within the bands.   They also hide the bottom of the fourth assessment band (orange FAR) so you can't see that observations are out of the envelope of the last report.  No one so far can figure out how they got the numbers in this chart, and it does not match any peer-reviewed work.  Steve McIntyre is trying to figure it out.

OK, so now that we are on the subject of climate models, here is the second hilarious thing Lovejoy said:

Does the leveling-off of temperatures mean that the climate models used to track them are seriously flawed? Not really. It is important to remember that models are used so that we can understand where the Earth system is headed.

Does this make any sense at all?  Try it in a different context:  The Fed said the fact that their economic models failed to predict what actually happened over the last 15 years is irrelevant because the models are only used to see where the economy is headed.

The consistent theme of this report is declining certainty and declining chances of catastrophe, two facts that the IPCC works as hard as possible to obfuscate but which still come out pretty clearly as one reads the report.

The Key Disconnect in the Climate Debate

Much of the climate debate turns on a single logical fallacy.  This fallacy is clearly on display in some comments by UK Prime Minister David Cameron:

It’s worth looking at what this report this week says – that [there is a] 95 per cent certainty that human activity is altering the climate. I think I said this almost 10 years ago: if someone came to you and said there is a 95 per cent chance that your house might burn down, even if you are in the 5 per cent that doesn’t agree with it, you still take out the insurance, just in case.”

"Human activity altering climate" is not the same thing as an environmental catastrophe (or one's house burning down).  The statement that he is 95% certain that human activity is altering climate is one that most skeptics (including myself) are 100% sure is true.  There is evidence that human activity has been altering the climate since the dawn of agriculture.  Man's changing land uses have been demonstrated to alter climate, and certainly man's incremental CO2 is raising temperatures somewhat.

The key question is -- by how much?  This is a totally different question, and, as I have written before, is largely dependent on climate theories unrelated to greenhouse gas theory, specifically that the Earth's climate system is dominated by large positive feedbacks.  (Roy Spenser has a good summary of the issue here.)

The catastrophe is so uncertain that for the first time, the IPCC left estimates of climate sensitivity to CO2 out of its recently released summary for policy makers, mainly because it was not ready to (or did not want to) deal with a number of recent studies yielding sensitivity numbers well below catastrophic levels.  Further, the IPCC nearly entirely punted on the key question of how it can reconcile its past high sensitivity/ high feedback based temperature forecasts with past relative modest measured warming rates, including a 15+ year pause in warming which none of its models predicted.

The overall tone of the new IPCC report is one of declining certainty -- they are less confident of their sensitivity numbers and less confident of their models which have all been a total failure over the last 15 years. They have also backed off of other statements, for example saying they are far less confident that warming is leading to severe weather.

Most skeptics are sure mankind is affecting climate somewhat, but believe that this effect will not be catastrophic.  On both fronts, the IPCC is slowly catching up to us.

Hearing What You Want to Hear from the Climate Report

After over 15 years of no warming, which the IPCC still cannot explain, and with climate sensitivity numbers dropping so much in recent studies that the IPCC left climate sensitivity estimates out of their summary report rather than address the drop, the Weather Channel is running this headline on their site:

weatherch

 

The IPCC does claim more confidence that warming over the past 60 years is partly or mostly due to man (I have not yet seen the exact wording they landed on), from 90% to 95%.  But this is odd given that the warming all came from 1978 to 1998 (see for yourself in temperature data about halfway through this post).  Temperatures are flat or cooling for the other 40 years of the period.  The IPCC cannot explain these 40 years of no warming in the context of high temperature sensitivities to CO2.  And, they can't explain why they can be 95% confident of what drove temperatures in the 20 year period of 1978-1998 but simultaneously have no clue what drove temperatures in the other years.

At some point I will read the thing and comment further.

 

Appeals to Authority

A reader sends me a story of global warming activist who clearly doesn't know even the most basic facts about global warming.  Since this article is about avoiding appeals to authority, so I hate to ask you to take my word for it, but it is simply impossible to immerse oneself in the science of global warming for any amount of time without being able to immediately rattle off the four major global temperature data bases (or at least one of them!)

I don't typically find it very compelling to knock a particular point of view just because one of its defenders is a moron, unless that defender has been set up as a quasi-official representative of that point of view (e.g. Al Gore).  After all, there are plenty of folks on my side of issues, including those who are voicing opinions skeptical of catastrophic global warming, who are making screwed up arguments.

However, I have found over time this to be an absolutely typical situation in the global warming advocacy world.  Every single time I have publicly debated this issue, I have understood the opposing argument, ie the argument for catastrophic global warming, better than my opponent.   In fact, I finally had to write a first chapter to my usual presentation.  In this preamble, I outline the case and evidence for manmade global warming so the audience could understand it before I then set out to refute it.

The problem is that the global warming alarm movement has come to rely very heavily on appeals to authority and ad hominem attacks in making their case.  What headlines do you see? 97% of scientists agree, the IPCC is 95% sure, etc.  These "studies", which Lord Monkton (with whom I often disagree but who can be very clever) calls "no better than a show of hands", dominate the news.  When have you ever seen a story in the media about the core issue of global warming, which is diagnosing whether positive feedbacks truly multiply small bits of manmade warming to catastrophic levels.  The answer is never.

Global warming advocates thus have failed to learn how to really argue the science of their theory.  In their echo chambers, they have all agreed that saying "the science is settled" over and over and then responding to criticism by saying "skeptics are just like tobacco lawyers and holocaust deniers and are paid off by oil companies" represents a sufficient argument.**  Which means that in an actual debate, they can be surprisingly easy to rip to pieces.  Which may be why most, taking Al Gore's lead, refuse to debate.

All of this is particularly ironic since it is the global warming alarmists who try to wrap themselves in the mantle of the defenders of science.  Ironic because the scientific revolution began only when men and women were willing to reject appeals to authority and try to understand things for themselves.

 

** Another very typical tactic:  They will present whole presentations without a single citation.   But make one statement in your rebuttal as a skeptic that is not backed with a named, peer-reviewed study, and they will call you out on it.  I remember in one presentation, I was presenting some material that was based on my own analysis.  "But this is not peer-reviewed" said one participant, implying that it should therefore be ignored.  I retorted that it was basic math, that the data sources were all cited, and they were my peers -- review it.  Use you brains.  Does it make sense?  Is there a flaw?  But they don't want to do that.  Increasingly, oddly, science is about having officially licensed scientists delivery findings to them on a platter.

IPCC: We Count on Lazy Reporters

We will see the final version of the IPCC's Fifth climate assessment soon.  But here is something interesting from the last draft circulated.  First, here is there chart comparing actual temperatures to model forecasts.  As you can see, all the actuals fall outside the published ranges from all previous reports (with a couple of the most recent data points added by Steve McIntyre in red).

click to enlarge

 

A problem, though not necessarily a fatal problem if the divergence can be explained.  And the IPCC is throwing out a lot of last minute explanations, though none of them are backed with any actual science.  I discussed one of these explanations here.  Anyway, you see their data above.  This is what they actually write in the text:

the globally-averaged surface temperatures are well within the uncertainty range of all previous IPCC projections, and generally are in the middle of the scenario ranges”.

This is completely absurd, of course, given their own data, but it has lasted through several drafts, so we will see if it makes it into the final draft.  My guess is that they will leave this issue out entirely in the summary for policy makers (the only part the media reads).  Steve McIntyre discusses the whole history of this divergence issue, along with a series of studies highlighting this divergence that have been consistently kept out of publication by climate gatekeepers.

The frustrating part is that the IPCC is running around saying they can't have a complete answer on this critical issue because it is so new.  By "new" they mean a frequent skeptics' observation and criticism of climate models for over a decade that they have only recently been forced under duress to finally consider.

Update On My Climate Model (Spoiler: It's Doing a Lot Better than the Pros)

In this post, I want to discuss my just-for-fun model of global temperatures I developed 6 years ago.  But more importantly, I am going to come back to some lessons about natural climate drivers and historic temperature trends that should have great relevance to the upcoming IPCC report.

In 2007, for my first climate video, I created an admittedly simplistic model of global temperatures.  I did not try to model any details within the climate system.  Instead, I attempted to tease out a very few (it ended up being three) trends from the historic temperature data and simply projected them forward.  Each of these trends has a logic grounded in physical processes, but the values I used were pure regression rather than any bottom up calculation from physics.  Here they are:

  • A long term trend of 0.4C warming per century.  This can be thought of as a sort of base natural rate for the post-little ice age era.
  • An additional linear trend beginning in 1945 of an additional 0.35C per century.  This represents combined effects of CO2 (whose effects should largely appear after mid-century) and higher solar activity in the second half of the 20th century  (Note that this is way, way below the mainstream estimates in the IPCC of the historic contribution of CO2, as it implies the maximum historic contribution is less than 0.2C)
  • A cyclic trend that looks like a sine wave centered on zero (such that over time it adds nothing to the long term trend) with a period of about 63 years.  Think of this as representing the net effect of cyclical climate processes such as the PDO and AMO.

Put in graphical form, here are these three drivers (the left axis in both is degrees C, re-centered to match the centering of Hadley CRUT4 temperature anomalies).  The two linear trends (click on any image in this post to enlarge it)

click to enlarge

 

And the cyclic trend:

click to enlarge

These two charts are simply added and then can be compared to actual temperatures.  This is the way the comparison looked in 2007 when I first created this "model"

click to enlarge

The historic match is no great feat.  The model was admittedly tuned to match history (yes, unlike the pros who all tune their models, I admit it).  The linear trends as well as the sine wave period and amplitude were adjusted to make the fit work.

However, it is instructive to note that a simple model of a linear trend plus sine wave matches history so well, particularly since it assumes such a small contribution from CO2 (yet matches history well) and since in prior IPCC reports, the IPCC and most modelers simply refused to include cyclic functions like AMO and PDO in their models.  You will note that the Coyote Climate Model was projecting a flattening, even a decrease in temperatures when everyone else in the climate community was projecting that blue temperature line heading up and to the right.

So, how are we doing?  I never really meant the model to have predictive power.  I built it just to make some points about the potential role of cyclic functions in the historic temperature trend.  But based on updated Hadley CRUT4 data through July, 2013, this is how we are doing:

click to enlarge

 

Not too shabby.  Anyway, I do not insist on the model, but I do want to come back to a few points about temperature modeling and cyclic climate processes in light of the new IPCC report coming soon.

The decisions of climate modelers do not always make sense or seem consistent.  The best framework I can find for explaining their choices is to hypothesize that every choice is driven by trying to make the forecast future temperature increase as large as possible.  In past IPCC reports, modelers refused to acknowledge any natural or cyclic effects on global temperatures, and actually made statements that a) variations in the sun's output were too small to change temperatures in any measurable way and b) it was not necessary to include cyclic processes like the PDO and AMO in their climate models.

I do not know why these decisions were made, but they had the effect of maximizing the amount of past warming that could be attributed to CO2, thus maximizing potential climate sensitivity numbers and future warming forecasts.  The reason for this was that the IPCC based nearly the totality of their conclusions about past warming rates and CO2 from the period 1978-1998.  They may talk about "since 1950", but you can see from the chart above that all of the warming since 1950 actually happened in that narrow 20 year window.  During that 20-year window, though, solar activity, the PDO and the AMO were also all peaking or in their warm phases.  So if the IPCC were to acknowledge that any of those natural effects had any influence on temperatures, they would have to reduce the amount of warming scored to CO2 between 1978 and 1998 and thus their large future warming forecasts would have become even harder to justify.

Now, fast forward to today.  Global temperatures have been flat since about 1998, or for about 15 years or so.  This is difficult to explain for the IPCC, since about none of the 60+ models in their ensembles predicted this kind of pause in warming.  In fact, temperature trends over the last 15 years have fallen below the 95% confidence level of nearly every climate model used by the IPCC.  So scientists must either change their models (eek!) or else they must explain why they still are correct but missed the last 15 years of flat temperatures.

The IPCC is likely to take the latter course.  Rumor has it that they will attribute the warming pause to... ocean cycles and the sun (those things the IPCC said last time were irrelevant).  As you can see from my model above, this is entirely plausible.  My model has an underlying 0.75C per century trend after 1945, but even with this trend actual temperatures hit a 30-year flat spot after the year 2000.   So it is entirely possible for an underlying trend to be temporarily masked by cyclical factors.

BUT.  And this is a big but.  You can also see from my model that you can't assume that these factors caused the current "pause" in warming without also acknowledging that they contributed to the warming from 1978-1998, something the IPCC seems loath to do.  I do not know how the ICC is going to deal with this.  I hate to think the worst of people, but I do not think it is beyond them to say that these factors offset greenhouse warming for the last 15 years but did not increase warming the 20 years before that.

We shall see.  To be continued....

Update:  Seriously, on a relative basis, I am kicking ass

click to enlarge

Climate Groundhog Day

I discuss in a bit more detail at my climate blog why I feel like climate blogging has become boring and repetitious.  To prove it, I predict in advance the stories that skeptics will run about the upcoming IPCC report.

I had a reader write to ask how I could be bored when there were still hilarious stories out there of climate alarmists trying to row through the Arctic and finding to their surprise it is full of ice.  But even this story repeats itself.  There have been such stories almost every year in the past five.

We Are 95% Confident in a Meaningless Statement

Apparently the IPCC is set to write:

Drafts seen by Reuters of the study by the U.N. panel of experts, due to be published next month, say it is at least 95 percent likely that human activities - chiefly the burning of fossil fuels - are the main cause of warming since the 1950s.

That is up from at least 90 percent in the last report in 2007, 66 percent in 2001, and just over 50 in 1995, steadily squeezing out the arguments by a small minority of scientists that natural variations in the climate might be to blame.

I have three quick reactions to this

  • The IPCC has always adopted words like "main cause" or "substantial cause."  They have not even had enough certainly to use the word "majority cause" -- they want to keep it looser than that.  If man causes 30% and every other cause is at 10% or less, is man the main cause?  No one knows.  So that is how we get to the absurd situation where folks are trumpeting being 95% confident in a statement that is purposely vaguely worded -- so vague that the vast majority of people who sign it would likely disagree with one another on exactly what they have agreed to.
  • The entirety of the post-1950 temperature rise occurred between 1978 and 1998 (see below a chart based on the Hadley CRUT4 database, the same one used by the IPCC

2013 Version 3 Climate talk

Note that temperatures fell from 1945 to about 1975, and have been flat from about 1998 to 2013.  This is not some hidden fact - it was the very fact that the warming slope was so steep in the short period from 1978-1998 that contributed to the alarm.  The current 15 years with no warming was not predicted and remains unexplained (at least in the context of the assumption of high temperature sensitivities to CO2).  The IPCC is in a quandary here, because they can't just say that natural variation counter-acted warming for 15 years, because this would imply a magnitude to natural variability that might have explained the 20 year rise from 1978-1998 as easily as it might explain the warming hiatus over the last 15 years (or in the 30 years preceding 1978).

  • This lead statement by the IPCC continues to be one of the great bait and switches of all time.  Most leading skeptics (excluding those of the talk show host or politician variety) accept that CO2 is a greenhouse gas and is contributing to some warming of the Earth.  This statement by the IPCC says nothing about the real issue, which is what is the future sensitivity of the Earth's temperatures to rising CO2 - is it high, driven by large positive feedbacks, or more modest, driven by zero to negative feedbacks.  Skeptics don't disagree that man has cause some warming, but believe that future warming forecasts are exaggerated and that the negative effects of warming (e.g. tornadoes, fires, hurricanes) are grossly exaggerated.

Its OK not to know something -- in fact, that is an important part of scientific detachment, to admit what one does not know.   But what the hell does being 95% confident in a vague statement mean?  Choose which of these is science:

  • Masses are attracted to each other in proportion to the product of their masses and inversely proportional to the square of their distance of separation.
  • We are 95% certain that gravity is the main cause of my papers remaining on my desk

Best and the Brightest May Finally Be Open To Considering Lower Climate Sensitivity Numbers

For years, readers of this site know that I have argued that:

  • CO2 is indeed a greenhouse gas, and since man is increasing its atmospheric concentration, there is likely some anthropogenic contribution to warming
  • Most forecasts, including those of the IPCC, grossly exaggerate temperature sensitivity to CO2 by assuming absurd levels of net positive feedback in the climate system
  • Past temperature changes are not consistent with high climate sensitivities

Recently, there have been a whole spate of studies based on actual observations rather than computer models that have been arriving at climate sensitivity numbers far below the IPCC number.   While the IPCC settled on 3C per doubling of CO2, it strongly implied that all the risk was to the upside, and many other prominent folks who typically get fawning attention in the media have proposed much higher numbers.

In fact, recent studies are coming in closer to 1.5C - 2C.  I actually still think these numbers will turn out to be high.  For several years now my money has been on a number from 0.8 to 1 C, sensitivity numbers that imply a small amount of negative feedback rather than positive feedback, a safer choice in my mind since most long-term stable natural systems are dominated by negative feedback.

Anyway, in an article that was as surprising as it is welcome, NY Times climate writer Andy Revkin has quite an article recently, finally acknowledging in the paper of record that maybe those skeptics who have argued for alower sensitivity number kind of sort of have a point.

Worse than we thought” has been one of the most durable phrases lately among those pushing for urgent action to stem the buildup of greenhouse gases linked to global warming.

But on one critically important metric — how hot the planet will get from a doubling of the pre-industrial concentration of greenhouse gases, a k a “climate sensitivity” — someclimate researchers with substantial publication records are shifting toward the lower end of the warming spectrum.

By the way, this is the only metric that matters.  All the other BS about "climate change" and "dirty weather" are meaningless without warming.  CO2 cannot change the climate  or raise sea levels or any of that other stuff by any mechanism we understand or that has even been postulated, except via warming.  Anyway, to continue:

There’s still plenty of global warming and centuries of coastal retreats in the pipeline, so this is hardly a “benign” situation, as some have cast it.

But while plenty of other climate scientists hold firm to the idea that the full range of possible outcomes, including a disruptively dangerous warming of more than 4.5 degrees C. (8 degrees F.), remain in play, it’s getting harder to see why the high-end projections are given much weight.

This is also not a “single-study syndrome” situation, where one outlier research paper is used to cast doubt on a bigger body of work — as Skeptical Science asserted over the weekend. That post focused on the as-yet-unpublished paper finding lower sensitivity that was inadvisedly promoted recently by the Research Council of Norway.

In fact, there is an accumulating body of reviewed, published researchshaving away the high end of the range of possible warming estimates from doubled carbon dioxide levels. Chief among climate scientists critical of the high-sensitivity holdouts is James Annan, an experienced climate modeler based in Japan who contributed to the 2007 science report from the Intergovernmental Panel on Climate Change. By 2006, he was already diverging from his colleagues a bit.

The whole thing is good.  Of course, for Revkin, this is no excuse to slow down all the actions supposedly demanded by global warming, such as substantially raising the price and scarcity of hydrocarbons.  Which to me simply demonstrates that people who have been against hydrocarbons have always been against them as an almost aesthetic choice, and climate change and global warming were mere excuses to push the agenda.  After all, as there certainly are tradeoffs to limiting economic growth and energy use and raising the price of energy, how can a reduction in postulated harms from fossil fuels NOT change the balance point one chooses in managing their use?

PS-  I thought this was a great post mortem on Hurricane Sandy and the whole notion that this one data point proves the global warming trend:

In this case several factors not directly related to climate change converged to generate the event. On Sandy’s way north, it ran into a vast high-pressure system over Canada, which prevented it from continuing in that direction, as hurricanes normally do, and forced it to turn west. Then, because it traveled about 300 miles over open water before making landfall, it piled up an unusually large storm surge. An infrequent jet-stream reversal helped maintain and fuel the storm. As if all that weren’t bad enough, a full moon was occurring, so the moon, the earth, and the sun were in a straight line, increasing the moon’s and sun’s gravitational effects on the tides, thus lifting the high tide even higher. Add to this that the wind and water, though not quite at hurricane levels, struck an area rarely hit by storms of this magnitude so the structures were more vulnerable and a disaster occurred.

The last one is a key for me -- you have cities on the Atlantic Ocean that seemed to build and act as if they were immune from ocean storms.  From my perspective growing up on the gulf coast, where one practically expects any structure one builds on the coast to be swept away every thirty years or so, this is a big contributing factor no one really talks about.

She goes on to say that rising sea levels may have made the storm worse, but I demonstrated that it couldn't have added more than a few percentage points to the surge.

Trusting Experts and Their Models

Russ Roberts over at Cafe Hayek quotes from a Cathy O’Neill review of Nate Silvers recent book:

Silver chooses to focus on individuals working in a tight competition and their motives and individual biases, which he understands and explains well. For him, modeling is a man versus wild type thing, working with your wits in a finite universe to win the chess game.

He spends very little time on the question of how people act inside larger systems, where a given modeler might be more interested in keeping their job or getting a big bonus than in making their model as accurate as possible.

In other words, Silver crafts an argument which ignores politics. This is Silver’s blind spot: in the real world politics often trump accuracy, and accurate mathematical models don’t matter as much as he hopes they would....

My conclusion: Nate Silver is a man who deeply believes in experts, even when the evidence is not good that they have aligned incentives with the public.

Distrust the experts

Call me “asinine,” but I have less faith in the experts than Nate Silver: I don’t want to trust the very people who got us into this mess, while benefitting from it, to also be in charge of cleaning it up. And, being part of the Occupy movement, I obviously think that this is the time for mass movements.

Like Ms. O'Neill, I distrust "authorities" as well, and have a real problem with debates that quickly fall into dueling appeals to authority.  She is focusing here on overt politics, but subtler pressure and signalling are important as well.  For example, since "believing" in climate alarmism in many circles is equated with a sort of positive morality (and being skeptical of such findings equated with being a bad person) there is an underlying peer pressure that is different from overt politics but just as damaging to scientific rigor.  Here is an example from the comments at Judith Curry's blog discussing research on climate sensitivity (which is the temperature response predicted if atmospheric levels of CO2 double).

While many estimates have been made, the consensus value often used is ~3°C. Like the porridge in “The Three Bears”, this value is just right – not so great as to lack credibility, and not so small as to seem benign.

Huybers (2010) showed that the treatment of clouds was the “principal source of uncertainty in models”. Indeed, his Table I shows that whereas the response of the climate system to clouds by various models varied from 0.04 to 0.37 (a wide spread), the variation of net feedback from clouds varied only from 0.49 to 0.73 (a much narrower relative range). He then examined several possible sources of compensation between climate sensitivity and radiative forcing. He concluded:

“Model conditioning need not be restricted to calibration of parameters against observations, but could also include more nebulous adjustment of parameters, for example, to fit expectations, maintain accepted conventions, or increase accord with other model results. These more nebulous adjustments are referred to as ‘tuning’.”  He suggested that one example of possible tuning is that “reported values of climate sensitivity are anchored near the 3±1.5°C range initially suggested by the ad hoc study group on carbon dioxide and climate (1979) and that these were not changed because of a lack of compelling reason to do so”.

Huybers (2010) went on to say:

“More recently reported values of climate sensitivity have not deviated substantially. The implication is that the reported values of climate sensitivity are, in a sense, tuned to maintain accepted convention.”

Translated into simple terms, the implication is that climate modelers have been heavily influenced by the early (1979) estimate that doubling of CO2 from pre-industrial levels would raise global temperatures 3±1.5°C. Modelers have chosen to compensate their widely varying estimates of climate sensitivity by adopting cloud feedback values countering the effect of climate sensitivity, thus keeping the final estimate of temperature rise due to doubling within limits preset in their minds.

There is a LOT of bad behavior out there by models.  I know that to be true because I used to be a modeler myself.  What laymen do not understand is that it is way too easy to tune and tweak and plug models to get a preconceived answer -- and the more complex the model, the easier this is to do in a non-transparent way.  Here is one example, related again to climate sensitivity

When I looked at historic temperature and CO2 levels, it was impossible for me to see how they could be in any way consistent with the high climate sensitivities that were coming out of the IPCC models.  Even if all past warming were attributed to CO2  (a heroic assertion in and of itself) the temperature increases we have seen in the past imply a climate sensitivity closer to 1 rather than 3 or 5 or even 10  (I show this analysis in more depth in this video).

My skepticism was increased when several skeptics pointed out a problem that should have been obvious.  The ten or twelve IPCC climate models all had very different climate sensitivities — how, if they have different climate sensitivities, do they all nearly exactly model past temperatures?  If each embodies a correct model of the climate, and each has a different climate sensitivity, only one (at most) should replicate observed data.  But they all do.  It is like someone saying she has ten clocks all showing a different time but asserting that all are correct (or worse, as the IPCC does, claiming that the average must be the right time).

The answer to this paradox came in a 2007 study by climate modeler Jeffrey Kiehl.  To understand his findings, we need to understand a bit of background on aerosols.  Aerosols are man-made pollutants, mainly combustion products, that are thought to have the effect of cooling the Earth’s climate.

What Kiehl demonstrated was that these aerosols are likely the answer to my old question about how models with high sensitivities are able to accurately model historic temperatures.  When simulating history, scientists add aerosols to their high-sensitivity models in sufficient quantities to cool them to match historic temperatures.  Then, since such aerosols are much easier to eliminate as combustion products than is CO2, they assume these aerosols go away in the future, allowing their models to produce enormous amounts of future warming.

Specifically, when he looked at the climate models used by the IPCC, Kiehl found they all used very different assumptions for aerosol cooling and, most significantly, he found that each of these varying assumptions were exactly what was required to combine with that model’s unique sensitivity assumptions to reproduce historical temperatures.  In my terminology, aerosol cooling was the plug variable.

By the way, this aerosol issue is central to recent work that is pointing to a much lower climate sensitivity to CO2 than has been reported in past IPCC reports.

Worst Chart Ever?

Kevin Drum posts this chart with a straight face as "proof" that sea level rise is out-pacing forecasts.

I don't really think I need to even point out the problem to most of my readers, but you can see the differences in ending value is because the starting values are different.  Likely the two are drawing from different data sources with a shifted zero value.  The slopes are the same, confirmed by the fact that the 3.2 mm trend per year is well within the IPCC forecast range that was centered, if I remember right, around 3.3 mm per year.  It is also well under Al Gore's forecast, which was for 20 feet by 2100, or about 61 mm per year.

I Was Reading Matt Ridley's Lecture at the Royal Society for the Arts....

... and it was fun to see my charts in it!  The lecture is reprinted here (pdf) or here (html).  The charts I did are around pages 6-7 of the pdf, the ones showing the projected curve of global warming for various climate sensitivities, and backing into what that should imply for current warming.  In short, even if you don't think warming in the surface temperature record is exaggerated, there still has not been anywhere near the amount of warming one would expect for the types of higher sensitivities in the IPCC and other climate models.  Warming to date, even if not exaggerated and all attributed to man-made and not natural causes, is consistent with far less catastrophic, and more incremental, future warming numbers.

These charts come right out of the IPCC formula for the relationship between CO2 concentrations and warming, a formula first proposed by Michael Mann.  I explained these charts in depth around the 10 minute mark of this video, and returned to them to make the point about past warming around the 62 minute mark.   This is a shorter video, just three minutes, that covers the same ground.  Watching it again, I am struck by how relevant it is as a critique five years later, and by how depressing it is that this critique still has not penetrated mainstream discussion of climate.  In fact, I am going to embed it below:

The older slides Ridley uses, which are cleaner (I went back and forth on the best way to portray this stuff) can be found here.

By the way, Ridley wrote an awesome piece for Wired more generally about catastrophism which is very much worth a read.

The Real Issue in Climate

I know I hammer this home constantly, but it is often worth a reminder.  The issue in the scientific debate over catastrophic man-made global warming theory is not whether CO2 is a greenhouse gas, or even the approximate magnitude of warming from CO2 directly, but around feedbacks.   Patrick Moore, Greenpeace founder, said it very well:

What most people don't realize, partly because the media never explains it, is that there is no dispute over whether CO2 is a greenhouse gas, and all else being equal would result in a warming of the climate. The fundamental dispute is about water in the atmosphere, either in the form of water vapour (a gas) or clouds (water in liquid form). It is generally accepted that a warmer climate will result in more water evaporating from the land and sea and therefore resulting in a higher level of water in the atmosphere, partly because the warmer the air is the more water it can hold. All of the models used by the IPCC assume that this increase in water vapour will result in a positive feedback in the order of 3-4 times the increase in temperature that would be caused by the increase in CO2 alone.

Many scientists do not agree with this, or do not agree that we know enough about the impact of increased water to predict the outcome. Some scientists believe increased water will have a negative feedback instead, due to increased cloud cover. It all depends on how much, and a t what altitudes, latitudes and times of day that water is in the form of a gas (vapour) or a liquid (clouds). So if  a certain increase in CO2 would theoretically cause a 1.0C increase in temperature, then if water caused a 3-4 times positive feedback the temperature would actually increase by 3-4C. This is why the warming predicted by the models is so large. Whereas if there was a negative feedback of 0.5 times then the temperature would only rise 0.5C.

My slightly lengthier discussions of this same issue are here and here.

A Vivid Reminder of How The Climate Debate is Broken

My Forbes column is up this week.  I really did not want to write about climate, but when Forbes conctributor Steve Zwick wrote this, I had to respond

We know who the active denialists are – not the people who buy the lies, mind you, but the people who create the lies.  Let’s start keeping track of them now, and when the famines come, let’s make them pay.  Let’s let their houses burn.  Let’s swap their safe land for submerged islands.  Let’s force them to bear the cost of rising food prices.

They broke the climate.  Why should the rest of us have to pay for it?

The bizarre threats and ad hominem attacks have to stop.  Real debate is necessary based on an assumption that our opponents may be wrong, but are still people of good will.  And we need to debate what really freaking matters:

Instead of screwing around in the media trying to assign blame for the recent US heat wave to CO2 and threatening to burn down the houses of those who disagree with us, we should be arguing about what matters.  And the main scientific issue that really matters is understanding climate feedback.  I won't repeat all of the previous posts (see here and here), but this is worth repeating:

Direct warming from the greenhouse gas effect of CO2 does not create a catastrophe, and at most, according to the IPCC, might warm the Earth another degree over the next century.  The catastrophe comes from the assumption that there are large net positive feedbacks in the climate system that multiply a small initial warming from CO2 many times.  It is this assumption that positive feedbacks dominate over negative feedbacks that creates the catastrophe.  It is telling that when prominent supporters of the catastrophic theory argue the science is settled, they always want to talk about the greenhouse gas effect (which most of us skeptics accept), NOT the positive feedback assumption.  The assumption of net positive climate feedback is not at all settled -- in fact there is as much evidence the feedback is net negative as net positive -- which may be why catastrophic theory supporters seldom if ever mention this aspect of the science in the media.

I said I would offer a counter-proposal to Mr. Zwick's that skeptics bear the costs of climate change.  I am ready to step up to the cost of any future man-made climate change if Mr. Zwick is ready to write a check for the lost economic activity and increased poverty caused by his proposals.  We are at an exciting point in history where a billion people, or more, in Asia and Africa and Latin America are at the cusp of emerging from millenia of poverty.  To do so, they need to burn every fossil fuel they can get their hands on, not be forced to use rich people's toys like wind and solar.  I am happy to trade my home for an imaginary one that Zwick thinks will be under water.  Not only is this a great way to upgrade to some oceanfront property, but I am fully confident the crazy Al Gore sea level rise predictions are a chimera, since sea levels have been rising at a fairly constant rate since the end of the little ice age..  In return, perhaps Mr. Zwick can trade his job for one in Asia that disappears when he closes the tap on fossil fuels?

I encourage you to read it all, including an appearance by the summer of the shark.

Climate Bait and Switch

Cross posted from Climate Skeptic

This quote from Michael Mann [of Hockey Stick fame] is a great example of two common rhetorical tactics of climate alarmists:

And so I think we have to get away from this idea that in matters of science, it's, you know, that we should treat discussions of climate change as if there are two equal sides, like we often do in the political discourse. In matters of science, there is an equal merit to those who are denying the reality of climate change who area few marginal individuals largely affiliated with special interests versus the, you know, thousands of scientists around the world. U.S. National Academy of Sciences founded by Abraham Lincoln back in the 19th century, all the national academies of all of the major industrial nations around the world have all gone on record as stating clearly that humans are warming the planet and changing the climate through our continued burning of fossil fuels.

Here are the two tactics at play here:

  1. He is attempting to marginalize skeptics so that debating their criticisms is not necessary.  He argues that skeptics are not people of goodwill; or that they say what they say because they are paid by nefarious interests to do so; or that they are vastly outnumbered by real scientists ("real" being defined as those who agree with Dr. Mann).  This is an oddly self-defeating argument, though the media never calls folks like Mann on it.  If skeptics' arguments are indeed so threadbare, then one would imagine that throwing as much sunlight on them as possible would reveal their bankruptcy to everyone, but instead most alarmists are begging the media, as in this quote, to bury and hide skeptics' arguments.  I LOVE to debate people when I know I am right, and have pre-debate trepidation only when I know my position to be weak.
  2. There is an enormous bait and switch going on in the last sentence.  Note the proposition is stated as "humans are warming the planet and changing the climate through our continued burning of fossil fuels."  I, and many other skeptics, don't doubt the first part and would quibble with the second only because so much poor science occurs in attributing specific instances of climate change to human action.  What most skeptics disagree with is an entirely different proposition, that humans are warming the planet to catastrophic levels that justify immensely expensive and coercive government actions to correct.  Skeptics generally accept a degree or so of warming from each doubling of CO2 concentrations but reject the separate theory that the climate is dominated by positive feedback effects that multiple this warming 3x or more.   Mann would never be caught dead in public trying to debate this second theory of positive feedback, despite the fact that most of the warming in IPCC forecasts is from this second theory, because it is FAR from settled.  Again, the media is either uninterested or intellectually unable to call him on this.
I explained the latter points in much more detail at Forbes.com

Fritz Vahrenholt Climate Book

A lot of folks have asked me if I am going to comment on this

One of the fathers of Germany’s modern green movement, Professor Dr. Fritz Vahrenholt, a social democrat and green activist, decided to author a climate science skeptical book together with geologist/paleontologist Dr. Sebastian Lüning. Vahrenholt’s skepticism started when he was asked to review an IPCC report on renewable energy. He found hundreds of errors. When he pointed them out, IPCC officials simply brushed them aside. Stunned, he asked himself, “Is this the way they approached the climate assessment reports?”

I have not seen the book nor the Der Spiegel feature, but I can say that, contrary to the various memes running around, many science-based skeptics became such by exactly this process -- looking at the so-called settled science and realizing a lot of it was really garbage.  Not because we were paid off in oil money or mesmerized by Rush Limbaugh, but because the actual detail behind many of the IPCC conclusions is really a joke.

For tomorrow, I am working on an article I have been trying to write literally for years.  One of the confusing parts of the climate debate is that there are really portions of the science that are pretty solid.  When skeptics point to other parts of the science that is not well-done, defenders tend to run back to the solid parts and point to those.  That is why Michael Mann frequently answers his critics by saying that skeptics are dumb because they don't accept greenhouse gas theory, but most skeptics do indeed accept greenhouse gas theory, what they don't accept is the separate theory that the climate is dominated by positive feedbacks that amplify small warming from CO2 into a catastrophe.

This is an enormous source of confusion in the debate, facilitated by a scientifically illiterate press and alarmists who explicitly attempt to make this bate and switch so they can avoid arguing the tough points.  Even the author linked above is confused on this

Skeptic readers should not think that the book will fortify their existing skepticism of CO2 causing warming. The authors agree it does. but have major qualms about the assumed positive CO2-related feed-backs and believe the sun plays a far greater role in the whole scheme of things.

This is in fact exactly the same position that most skeptics, at least the science-based non-talkshow-host ones have.  Look for my Forbes piece tomorrow.

Katrina Flashback

It is December, 2005.  The Gulf Coast had just been pounded, in succession, by Katrina, Rita, and Wilma.  Everyone was talking about how global warming seemed to be intensifying hurricanes.  In a speech just after Katrina, Al Gore said

 When the corpses of American citizens are floating in toxic floodwaters five days after a hurricane strikes, it is time not only to respond directly to the victims of the catastrophe but to hold the processes of our nation accountable, and the leaders of our nation accountable, for the failures that have taken place....

There are scientific warnings now of another onrushing catastrophe. We were warned of an imminent attack by Al Qaeda; we didn't respond. We were warned the levees would break in New Orleans; we didn't respond. Now, the scientific community is warning us that the average hurricane will continue to get stronger because of global warming. A scientist at MIT has published a study well before this tragedy showing that since the 1970s, hurricanes in both the Atlantic and the Pacific have increased in duration, and in intensity, by about 50 percent....

Two thousand scientists, in 100 countries, engaged in the most elaborate, well-organized scientific collaboration in the history of humankind, have produced long-since a consensus that we will face a string of terrible catastrophes unless we act to prepare ourselves and deal with the underlying causes of global warming....

At about the same time, the IPCC was in the process of preparing its fourth report, later released in 2007.  It said, in part:

Several peer-reviewed studies show a clear global trend toward increased intensity of the strongest hurricanes over the past two or three decades. The strongest trends are in the North Atlantic Ocean and the Indian Ocean. According to the 2007 Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC-AR4), it is “more likely than not” (better than even odds) that there is a human contribution to the observed trend of hurricane intensification since the 1970s. In the future, “it is likely [better than 2 to 1 odds] that future tropical cyclones (typhoons and hurricanes) will become more intense, with larger peak wind speeds and more heavy precipitation associated with ongoing increases of tropical [sea surface temperatures].”

So what happened?  Since Wilma in 2005, we have gone 6 full years without a category 3+ hurricane making landfall in the US, the longest span since 1900 without such an event.  And the clock is still counting.  When alarmists of all stripes were breathlessly predicting hurricane after hurricane in late 2005, the reality is that we wouldn't see another in the US for  over six years.

Of course, US landfall is in fact a terrible indicator of hurricane activity.  Its relevant to us, but it is a pretty random metric.  I said this when there were a lot of landfalls and I say it again since there have been so few.

A better metric is accumulated cyclonic energy, a sort of time integral of all large cyclonic storms worldwide.  Here is the most recent ACE figures:

As it turns out, the total strength of hurricane and hurricane-like storms has been falling almost since the exact day of Al Gore's speech in 2005 (another Gore effect!)  In fact, of late, it has hit numbers close to all-time lows.

Of course this chart will go back up some day, and then back down, and then up ... because hurricane activity has always been cyclical over decadal time scales.

The media loves to trumpet end-of-the-world predictions from folks like Al Gore and Paul Ehrlich, but they never go back five years later and back-check their predictions.  And despite their horrendous record for accuracy, the media eagerly publishes the next one.  Here is a proposed editorial rule for the MSM -- no breathless publication of anyone's next prediction without first revisiting the last one.

The Missing Heat

It is possible for the theory that the climate has a high sensitivity to CO2 (ie that a doubling of CO2 concentrations will lead to global temperature increases of 2.5C or higher) to be correct while still having ten years of flat to declining surface temperatures.  That is because Earth's great surface heat reservoir is the oceans, not the atmosphere, and so the extra heat from the greenhouse effect could be going into the oceans rather than into near-surface air.

However, it is NOT possible, as least as we (and by "we" I mean everyone, skeptics and alarmists alike) understand the climate, for CO2 to be holding a lot of extra heat and it not show up either in surface temperatures or ocean heat content.  The greenhouse effect does not turn off -- its effects may be masked in the chaotic weather systems, perhaps for years, but if the climate sensitivity to CO2 is really as high as the IPCC says, there has to be new heat going somewhere.

That is why a number of folks, including Roger Pielke, have argued for years that the best way to monitor whether we are truly seeing an additional forcing or heat input to the climate is to look at ocean heat content.  Understand, changes in ocean heat content would not tell us where the heat is coming from (e.g. anthropogenic CO2 vs. solar activity).  But it is pretty much impossible for us to imagine a new heat input to the Earth's surface, like greenhouse gas forcing from anthropogenic CO2, without observing its effect in ocean heat content.

I will turn over the story to Jo Nova, who has a good post on the new tools we have to measure ocean heat content since 2003.  In short, though, we have seen no rise in measured ocean heat content since we started measuring with technology dedicated to the task.  This means, if those who believe the climate has a high sensitivity to CO2 are right, something like 50,000 quintillion joules of energy have gone missing since 2003.  This is the "missing heat", and though climate scientists sometimes discuss it in private, they almost never do so in public.  Ocean heat is the dinosaur bone fossil that the creationists simply don't want to acknowledge.

Read the whole thing.  It is very simple and well-written and written.

PS- note in the chart above, the y-axis is mis-labelled a bit, it is not absolute heat content but changes in heat content from some base period.  Scientists call this the "anomaly."  This is typical of many climate charts.

Krugman Unintended Irony: Anyone Who Does Not Unquestioningly Believe Authorities is Anti-Science

here.

It's a wonder how, when over "97 percent to 98 percent" of scientific authorities accepted the Ptolomeic view of the solar system that we ever got past that.  Though I could certainly understand why in the current economy a die-hard Keynesian might be urging an appeal to authority rather than thinking for oneself.

When, by the way, did the children of the sixties not only lose, but reverse their anti-authoritarian streak?

Postscript:  I have always really hated the nose-counting approach to measuring the accuracy of a scientific hypothesis.  If we want to label something as anti-science, how about using straw polls of scientists as a substitute for fact-based arguments?

Yes indeed, the number of people in the newly made-up profession of "climate science" that are allowed by the UN control the content of the IPCC reports and whose funding is dependent on global warming being scary probably is very high.  The number of people in traditional scientific fields like physics, geology, chemistry, oceanography and meteorology who never-the-less study climate related topics that wholeheartedly are all-in for catastrophic man-made global warming theory would be very different

 Decide for yourself - see my video on global warming.  Am I anti-science?

Digging into the Climate Models

My article this week at Forbes.com digs into some fundamental flaws of climate models

When I looked at historic temperature and CO2 levels, it was impossible for me to see how they could be in any way consistent with the high climate sensitivities that were coming out of the IPCC models.  Even if all past warming were attributed to CO2  (a heroic acertion in and of itself) the temperature increases we have seen in the past imply a climate sensitivity closer to 1 rather than 3 or 5 or even 10  (I show this analysis in more depth in this video).

My skepticism was increased when several skeptics pointed out a problem that should have been obvious.  The ten or twelve IPCC climate models all had very different climate sensitivities — how, if they have different climate sensitivities, do they all nearly exactly model past temperatures?  If each embodies a correct model of the climate, and each has a different climate sensitivity, only one (at most) should replicate observed data.  But they all do.  It is like someone saying she has ten clocks all showing a different time but asserting that all are correct (or worse, as the IPCC does, claiming that the average must be the right time).

The answer to this paradox came in a 2007 study by climate modeler Jeffrey Kiehl.  To understand his findings, we need to understand a bit of background on aerosols.  Aerosols are man-made pollutants, mainly combustion products, that are thought to have the effect of cooling the Earth’s climate.

What Kiehl demonstrated was that these aerosols are likely the answer to my old question about how models with high sensitivities are able to accurately model historic temperatures.  When simulating history, scientists add aerosols to their high-sensitivity models in sufficient quantities to cool them to match historic temperatures.  Then, since such aerosols are much easier to eliminate as combustion products than is CO2, they assume these aerosols go away in the future, allowing their models to produce enormous amounts of future warming.

Specifically, when he looked at the climate models used by the IPCC, Kiehl found they all used very different assumptions for aerosol cooling and, most significantly, he found that each of these varying assumptions were exactly what was required to combine with that model’s unique sensitivity assumptions to reproduce historical temperatures.  In my terminology, aerosol cooling was the plug variable.

Climate Feedback

Take all the psuedo-quasi-scientific stuff you read in the media about global warming.  Of all that mess, it turns out there is really only one scientific question that really matters on the topic of man-made global warming: Feedback.

While the climate models are complex, and the actual climate even, err, complexer, we can shortcut the reaction of global temperatures to CO2 to a single figure called climate sensitivity.  How many degrees of warming should the world expect for each doubling of CO2 concentrations  (the relationship is logarithmic, so that is why sensitivity is based on doublings, rather than absolute increases -- an increase of CO2 from 280 to 290 ppm should have a higher impact on temperatures than the increase from, say, 380 to 390 ppm).

The IPCC reached a climate sensitivity to CO2 of about 3C per doubling.  More popular (at least in the media) catastrophic forecasts range from 5C on up to about any number you can imagine, way past any range one might consider reasonable.

But here is the key fact -- Most folks, including the IPCC, believe the warming sensitivity from CO2 alone (before feedbacks) is around 1C or a bit higher (arch-alarmist Michael Mann did the research the IPCC relied on for this figure).  All the rest of the sensitivity between this 1C and 3C or 5C or whatever the forecast is comes from feedbacks (e.g. hotter weather melts ice, which causes less sunlight to be reflected, which warms the world more).  Feedbacks, by the way can be negative as well, acting to reduce the warming effect.  In fact, most feedbacks in our physical world are negative, but alarmist climate scientists tend to assume very high positive feedbacks.

What this means is that 70-80% or more of the warming in catastrophic warming forecasts comes from feedback, not CO2 acting alone.   If it turns out that feedbacks are not wildly positive, or even are negative, then the climate sensitivity is 1C or less, and we likely will see little warming over the next century due to man.

This means that the only really important question in the manmade global warming debate is the sign and magnitude of feedbacks.  And how much of this have you seen in the media?  About zero?  Nearly 100% of what you see in the media is not only so much bullshit (like whether global warming is causing the cold weather this year) but it is also irrelevant.  Entirely tangential to the core question.  Its all so much magician handwaving trying to hide what is going on, or in this case not going on, with the other hand.

To this end, Dr. Roy Spencer has a nice update.  Parts are a bit dense, but the first half explains this feedback question in layman's terms.  The second half shows some attempts to quantify feedback.  His message is basically that no one knows even the sign and much less the magnitude of feedback, but the empirical data we are starting to see (which has admitted flaws) points to negative rather than positive feedback, at least in the short term.  His analysis looks at the change in radiative heat transfer in and out of the earth as measured by satellites around transient peaks in ocean temperatures (oceans are the world's temperature flywheel -- most of the Earth's surface heat content is in the oceans).

Read it all, but this is an interesting note:

In fact, NO ONE HAS YET FOUND A WAY WITH OBSERVATIONAL DATA TO TEST CLIMATE MODEL SENSITIVITY. This means we have no idea which of the climate models projections are more likely to come true.

This dirty little secret of the climate modeling community is seldom mentioned outside the community. Don’t tell anyone I told you.

This is why climate researchers talk about probable ranges of climate sensitivity. Whatever that means!…there is no statistical probability involved with one-of-a-kind events like global warming!

There is HUGE uncertainty on this issue. And I will continue to contend that this uncertainty is a DIRECT RESULT of researchers not distinguishing between cause and effect when analyzing data.

If you find this topic interesting, I recommend my video and/or powerpoint presentation to you.

A New Scientific Low

I am really just amazed by these remarks by NCAR's Dr. Ken Trenberth to be given, apparently planned for the American Meteorological Society gathering this month.   The pdf is here and Anthony Watt has reprinted it on his blog.

It is hard to know where to start, but the following excerpt is an outstanding example of climate science process where 1.  Conclusions are assumed; 2.  Conclusions are deemed unequivocal by reference to authority; 3. Debate rules are proposed wherin it is impossible to refute the conclusion; 4.  All weather events that make the news are assumed to be caused or made worse by man-made warming, and thereby, in circular fashion, further prove the theory.

Normally, when I cite the above as the process, I get grief from folks who say I am mis-interpreting things, as usually I am boiling a complex argument down to this summary.   The great thing about alarmist Trenberth's piece is that no interpretation is necessary.   He outlines this process right in a single paragraph.  I will label the four steps above

Given that global warming is “unequivocal” [1], to quote the 2007 IPCC report [2], the null hypothesis should now be reversed, thereby placing the burden of proof on showing that there is no human influence [3]. Such a null hypothesis is trickier because one has to hypothesize something specific, such as “precipitation has increased by 5%” and then prove that it hasn’t. Because of large natural variability, the first approach results in an outcome suggesting that it is appropriate to conclude that there is no increase in precipitation by human influences, although the correct interpretation is that there is simply not enough evidence (not a long enough time series). However, the second approach also concludes that one cannot say there is not a 5% increase in precipitation. Given that global warming is happening and is pervasive, the first approach should no longer be used. As a whole the community is making too many type II errors [4].

Are you kidding me -- if already every damn event in the tails of the normal distribution is taken by the core climate community as a proof of their hypothesis, how is there even room for type II errors?  Next up -- "Our beautiful, seasonal weather -- proof of global warming?"

Remember that the IPCC's conclusion of human-caused warming was based mainly on computer modelling.  The IPCC defenders will not admit this immediately, but press them hard enough on side arguments and it comes down to the models.

The summary of their argument is this:  for the period after 1950, they claim their computer models cannot explain warming patterns without including a large effect from anthropogenic CO2.  Since almost all the warming in the latter half of the century really occurred between 1978 and 1998, the IPCC core argument boils down to "we are unable to attribute the global temperature increase in these 20 years to natural factors, so it must have been caused by man-made CO2."  See my video here for a deeper discussion.

This seems to be a fairly thin reed.  After all, it may just be that after only a decade or two of serious study, we still do not understand climate variability very well, natural or not.  It is a particularly odd conclusion when one discovers that the models ignore a number of factors (like the PDO, ENSO, etc) that affect temperatures on a decadal scale.

We therefore have a hypothesis that is not based on observational data, and where those who hold the hypothesis claim that observational data should no longer be used to test their hypothesis.    He is hilarious when he says that reversing the null hypothesis would make it trickier for his critics.  It would make it freaking impossible, as he very well knows.  This is an unbelievingly disingenuous suggestion.  There are invisible aliens in my closet Dr. Trenberth -- prove me wrong.  It is always hard to prove a negative, and impossible in the complex climate system.  There are simply too many variables in flux to nail down cause and effect in any kind of definitive way, at least at our level of understanding  (we have studied economics much longer and we still have wild disagreements about cause and effect in macroeconomics).

He continues:

So we frequently hear that “while this event is consistent with what we expect from climate change, no single event can be attributed to human induced global warming”. Such murky statements should be abolished. On the contrary, the odds have changed to make certain kinds of events more likely. For precipitation, the pervasive increase in water vapor changes precipitation events with no doubt whatsoever. Yes, all events! Even if temperatures or sea surface temperatures are below normal, they are still higher than they would have been, and so too is the atmospheric water vapor amount and thus the moisture available for storms. Granted, the climate deals with averages. However, those averages are made up of specific events of all shapes and sizes now operating in a different environment. It is not a well posed question to ask “Is it caused by global warming?” Or “Is it caused by natural variability?” Because it is always both.

At some level, this is useless.   The climate system is horrendously complex.  I am sure everything affects everything.  So to say that it affects the probability is a true but unhelpful statement.   The concern is that warming will affect the rate of these events, or the severity of these events, in a substantial and noticeable way.

It is worth considering whether the odds of the particular event have changed sufficiently that one can make the alternative statement “It is unlikely that this event would have occurred without global warming.” For instance, this probably applies to the extremes that occurred in the summer of 2010: the floods in Pakistan, India, and China and the drought, heat waves and wild fires in Russia.

Now he has gone totally off the scientific reservation into astrology or the occult or something.   He is saying that there is a high probability that if CO2 levels were 120ppm lower that, for example, the floods in Pakistan would not have occurred.  This is pure conjecture, absolutely without facts, and probably bad conjecture at that.  After all, similar events of similar magnitude have occurred through all of recorded history in exactly these locations.

Some Notes

1.  For those unfamiliar with the issues, few skeptics deny that man's CO2 has no effect on warming, but believe the effect is being enormously exaggerated.  There is a bait and switch here, where the alarmist claims that "man is causing some warming" is the key conclusion, and once accepted, they can head off and start controlling the world's economy (and population, as seems to be desired by Trenberth).   But the fact that CO2 causes some greenhouse warming is a trivial conclusion.  The hard part is, in the complex climate system, how much does it cause.  There is a an argument to be made, as I have, that this warming is less than 1C over the next century.  This number actually has observational data on its side, as actual warming over the last century, given past CO2 increases, is much more consistent with my lower number than various alarmist forecasts of doom.  Again, this is discussed in much more depth here.

2.  One interesting fact is that alarmists have to deal with the lack of warming or increase in ocean heat content over the last 12 years or so.  They will argue that this is just a temporary aberration, and a much shorter time frame than they are working on.  But in effect, the core IPCC conclusions were really based on the warming over the 20 years from 1978-1998.  So while 12 years is admittedly short compared to many natural cycles in climate, and might be considered a dangerously short period to draw conclusions from, it is fairly large compared to the 20 year period that drove the IPCC conclusions.

Update: More thoughts from the Reference Frame.

Science That Is Run Like a Soviet Election

News from the United Nations:

Robert Orr, UN under secretary general for planning, said the next Intergovernmental Panel on Climate Change report on global warming will be much worse than the last one.

Hmm, that kind of confirms what critics have been saying for years, that the IPCC has nothing to do with science.  Because, you see, to my knowledge the scientists of the next IPCC have not even started their work, but the UN leadership has already determined what the report will say.  Which is consistent with their process in the last go around, where the UN political guys crafted the management summary first, and then circulated it to the scientific teams with instructions to adjust their sections of the report to fit the pre-existing conclusion.

In the same article, we get more of the "accelerating" nonsense:

He said UN Secretary General Ban Ki-moon would make it clear to world leaders in Cancun "that we should not take any comfort in the climate deniers' siren call."

"The evidence shows us quite the opposite-- that we can't rest easy at all" as scientists agree that climate change "is happening in an accelerated way."

Its not even clear what the value of the first derivative is for climate change, or even if such a metric has any meaning in the complex climate system where regional trends can easily be going in opposite directions.  But anyone who can tell you that we know the second derivative, or even its sign, is totally full of crap.

Never (except perhaps with shark attack scares which come and go) have I seen such a classic case of observer bias.   Certain events occur in the tail ends of the normal distribution.  Suddenly everyone claims that these events are happening with more frequency, mainly because they get reported with more frequency. I reported on a great example of this from a supposedly scientific government report here, where researchers mistook improved measurement of certain events as a real underlying increase in the number of such events.  Another example here.

Of course, 95 percentile events can't be, by definition, happening more frequently.  The only thing that can happen is the normal distribution can have its standard deviation increase.  Similar to the second derivitive argument above, I am not a statistician, but my sense is that the odds that we could detect a standard deviation shift in the distribution of weather events using just a few years of highly imperfect data, even if such an underlying shift existed, is really  really low.

The Crux of the Climate Debate

Cross-posted from Climate Skeptic

I wanted to link to Richard Lindzen's Congressional testimony.  For slides, they are pretty easy to follow as they are mostly text.  I want to particularly point out slide 4, which I think on one page outlines the single most important point to understand about anthropogenic global warming theory.  When given just one minute to discuss climate, this slide embodies the message I give.

Here are two statements that are completely agreed on by the IPCC. It is crucial to be aware of their implications.

1. A doubling of CO2, by itself, contributes only about 1C to greenhouse warming. All models project more warming, because, within models, there are positive feedbacks from water vapor and clouds, and these feedbacks are considered by the IPCC to be uncertain.

2. If one assumes all warming over the past century is due to anthropogenic greenhouse forcing, then the derived sensitivity of the climate to a doubling of CO2is less than 1C. The higher sensitivity of existing models is made consistent with observed warming by invoking unknown additional negative forcings from aerosols and solar variability as arbitrary adjustments.

Given the above, the notion that alarming warming is "˜settled science' should be offensive to any sentient individual, though to be sure, the above is hardly emphasized by the IPCC. 4

My most recent climate video, which discusses this issue and more, is here.  I also have an older, shorter video focusing on just the issues in Lindzen's fourth slide here.