Archive for the ‘Climate’ Category.

Wherein I Come Clean to Representative Grijalva

Here is the letter I wrote today (pdf) to Representative Grijalva confessing my climate funding biases.  The image is below.  I feel so much better.


I wrote this in support particularly of Roger Pielke, who has educated a lot of people about climate and is not even really a climate skeptic and who has been pretty upset by this scrutiny.  Call it the "I am Spartacus" strategy.

My earlier post on funding and bias is here.

On Funding and Bias in Climate

I really, really did not want to have to write yet another post on this.  99+% of all climate funding goes to alarmists rather than skeptics.   Greenpeace laments donations of funds to skeptics by Exxon of a million dollars or so and wants to drive out all such funding when Greenpeace and Tides and the US Government are giving literally billions to alarmists.  Despite this staggering imbalance, the only stories you ever see are about the dangers and bias introduced by that measly 1% skeptics get.  I guess that 1% is spent pretty well because it sure seems to have people running in circles declaring the sky is falling.

One would think that at some point the world would wake up and realize that criticizing the funding sources behind an individual does not actually rebut that individual's arguments.

Potential bias introduced by funding sources (or some other influence) are a pointer -- they are an indication there might be a problem warranting deeper examination of the evidence introduced and the methodology of collecting that evidence.  Such potential biases are not themselves evidence, and do nothing to rebut an argument.  A reasonable way to use such biases in an argument would be something like:

I want to begin by noting that Joe may have had a predisposition to his stated conclusion even before he started because of [funding source, political view, whatever].  This means we need to very carefully look at how he got to his conclusion.  And I intend to show you that he made several important errors that should undermine our acceptance of his conclusions.  They are....

Unfortunately, nowadays people like the New York Times and our own Arizona Representative Raul Grijalva seem to feel like the job is done after the first sentence.  They have decided that the best way to refute recent scientific work by a number of climate scientists is to try to show that some of their funding comes from fossil fuel companies.

Beyond the strange implicit assumption that fossil fuel funding would automatically "disprove" a research paper, there is also an assumption that oil company funding is "unclean" while government or non-profit environmental group funding is "clean".  Remember the last time you saw a news story about a climate alarmist's funding?  Yeah, neither do I.

There is no justifiable reason for this asymmetry.  Funding does not potentially introduce bias because it is sourced from for-profit or non-profit entities.  In fact, the motivation of the funding source is virtually irrelevant.  The only relevant questions related to bias are:

  1. Did the funding source demand a certain conclusion at the outset of the study as the price of the funding -- or --
  2. Is there a reasonable expectation that the source would deny future funding if the conclusions of the study don't go their way

My sense is that #1 is rare and that the real issue is #2.

But #2 is ubiquitous.  Sure, if a group of skeptical scientists suddenly started writing papers about 8 degree warming predictions, Chevron is going to be less likely to fund their future research.  But on the flip side if Michael Mann suddenly started saying that future warming will only be a modest 1-2 degrees, do you think that he would continue to get funding from Greenpeace, the Tides Foundation, the WWF, or even from an Obama-run Federal agency?  No way.   There is absolutely no less bias introduced by Chevron funding than from Greenpeace funding, because in each case there can be a reasonable fear by the researcher that future funding would be denied by that source if the "right" answer was not reached.

Postscript & Disclosure of Biases:  I have never received any outside funding for this blog or my climate work.  However, if Chevron were to send me a check for a million dollars, I would probably cash it.  I do own individual shares of ExxonMobil stock as well as shares of the Vanguard S&P500 index fund, which includes equities of a number of energy companies.  I also am a frequent purchaser of gasoline and electricity, as well as a number of other products and services whose prices are tied to energy prices (e.g. air transportation).  As a consumer, I would rather not see the prices of these products rise.  I buy a lot of food, whose price might be improved by longer growing seasons.  My camping company tends to benefit from rising gasoline prices, because rising prices causes people to stay closer to home and camp at the type of places we operate.  It is hard to predict how regional climates will change if overall global temperatures rise, but since many of my campgrounds are summer escapes at high altitude, they would probably benefit somewhat from rising temperatures.  I own a home in Arizona whose value would probably be lessened if the world warmed 2-3 degrees, because it would make winters in the northeast and midwest more bearable and thus hurt Arizona as a location for a winter second home.  Global warming may reduce the life of my dog as we are less likely to walk her when it is over 100 degrees out which makes her less healthy.  I own land in Hawaii that might be more valuable if sea level rises puts it 6-8 inches close to the ocean.  I am planning a vacation to see the tulips bloom in Holland and changes in climate could shift the blooming date and thus cause me to miss the best colors.  Fifteen years from now my daughter would like a June wedding and changes to climate might cause it to rain that day.  My daughter also owns 5 shares of Walt Disney and their earnings might be helped by global warming as nostalgia for cooler weather could greatly increase DVD sales of "Frozen".

Skeptics: Please Relax on the Whole "Greatest Scientific Fraud of All Time" Thing

Climate skeptics are at risk of falling into the same exaggeration-trap as do alarmists.

I have written about the exaggeration of past warming by questionable manual adjustments to temperature records for almost a decade.  So I don't need to be convinced that these adjustments 1) need to be cleaned up and 2) likely exaggerate past warming.

However, this talk of the "Greatest Scientific Fraud of All Time" is just crazy.  If you are interested, I urge you read my piece from the other day for a more balanced view.  Don't stop reading without checking out #4.

These recent articles are making it sound like alarmist scientists are simply adding adjustments to past temperatures for no reason.  But there are many perfectly valid reasons surface temperature measurements have to be manually adjusted.  It is a required part of the process.  Just as the satellite data must be adjusted as well, though for different things.

So we should not be suspicious of adjustments per se.  We should be concerned about them, though, for a number of reasons:

  • In many parts of the world, like in the US, the manual adjustments equal or exceed the measured warming trend.  That means the"signal" we are measuring comes entirely from the adjustments.  That is, to put it lightly, not ideal.
  • The adjustments are extremely poorly documented and impossible for any third party to replicate (one reason the satellite record may be more trustworthy is all the adjustment code for the satellites is open source).
  • The adjustments may have a bias.  After all, most of the people doing the adjustments expect to see a warming trend historically, and so consider lack of such a trend to be an indicator the data is wrong and in need of adjustment.  This is not a conspiracy, but a normal human failing and the reason why the ability to replicate such work is important.
  • The adjustments do seem to be very aggressive in identifying any effects that might have artificially created a cooling trend but lax in finding and correcting effects that might have artificially created a warming trend.  First and foremost, the changing urban heat island effect in growing cities seems to be under-corrected  (Again there is debate on this -- the proprietors of the model believe they have fixed this with a geographic normalizing, correcting biases from nearby thermometers.  I and others believe all they are doing is mathematically smearing the error over a larger geography).

Again, I discussed all the pros and cons here.  If pushed to the wall, I would say perhaps half of the past warming in the surface temperature record is due to undercorrection of warming biases or overcorrection of cooling biases.

Bill Maher, Living in an Echo Chamber

I refuse to assume (contrary to the modern practice) that someone who disagrees with me is either stupid or ill-intentioned or both [OK, I did call people idiots here -- sorry, I was ranting].  Intelligent people of goodwill can disagree with each other, and the world would be a better place if more people embraced that simple notion.

Anyway, I won't blame lack of intelligence or bad motivations for the following statement from Bill Maher.  He seems to be a smart guy who is honestly motivated by what he says motivates him.  But this statement is just so ignorant and provably false that it must be the result of living in a very powerful echo chamber where no voices other than ones that agree with him are allowed.

HBO’s Bill Maher complained that comparing climate change skepticism to vaccine skepticism was unfair to vaccine skeptics before attacking GMOs on Friday’s “Real Time.”

“The analogy that I see all the time is that if you ask any questions [about vaccines], you are the same thing as a global warming denier. I think this is a very bad analogy, because I don’t think all science is alike. I think climate science is rather straightforward because you’re dealing with the earth, it’s a rock…climate scientists, from the very beginning, have pretty much said the same thing, and their predictions have pretty much come true. It’s atmospherics, and it’s geology, and chemistry. That’s not true of the medical industry. I mean, they’ve had to retract a million things because the human body is infinitely more mysterious” he stated.

Climate science is astoundingly complex with thousands or millions of variables interacting chaotically.  Separating cause and effect is a nightmare, because controlled experiments are impossible.  It is stupendously laughable that he could think this task somehow straightforward, or easier than running a double-blind medical study  (By the way, this is one reason for the retractions in medicine vs. climate -- medical studies are straightforward enough they can be easily replicated... or not, and thus retracted.  Proving cause and effect in climate is so hard that studies may be of low quality, but they are also hard to absolutely disprove).

It is funny of course that he would also say that all of climate scientists predictions have come true.  Pretty much none have come true.  They expected  rapidly rising temperatures and they have in fact risen only modestly, if at all, over the last 20 years or so.  They expected more hurricanes and there have been fewer.  They called for more tornadoes and there have been fewer.  The only reason any have been right at all is that climate scientists have separately forecasts opposite occurrences (e.g. more snow / less snow) so someone has to be right, though this state of affairs hardly argues for the certainty of climate predictions.

By the way, the assumption that Bill Maher is an intelligent person of goodwill who simply disagrees with me on things like climate and vaccines and GMO's is apparently not one he is willing to make himself about his critics.  e.g.:

Weekly Standard Senior Writer John McCormack then pointed out that there are legitimate scientists, such as Dr. Richard Lindzen, who are skeptical of man-made climate change theories, but that there were no serious vaccine-skeptic professors, to which Maher rebutted “the ones who are skeptics [on climate change], usually are paid off by the oil industry.”

I will point out to you that the Left's positions on climate, vaccines, and GMO's have many things in common, as I wrote in a long article on evaluating risks here.

Adjusting the Temperature Records

I have been getting inquiries from folks asking me what I think about stories like this one, where Paul Homewood has been looking at the manual adjustments to raw temperature data and finding that the adjustments actually reverse the trends from cooling to warming.  Here is an example of the comparisons he did:

Raw, before adjustments;



After manual adjustments



I actually wrote about this topic a few months back, and rather than rewrite the post I will excerpt it below:

I believe that there is both wheat and chaff in this claim [that manual temperature adjustments are exaggerating past warming], and I would like to try to separate the two as best I can.  I don't have time to write a well-organized article, so here is just a list of thoughts

  1. At some level it is surprising that this is suddenly news.  Skeptics have criticized the adjustments in the surface temperature database for years.
  2. There is certainly a signal to noise ratio issue here that mainstream climate scientists have always seemed insufficiently concerned about.  For example, the raw data for US temperatures is mostly flat, such that the manual adjustments to the temperature data set are about equal in magnitude to the total warming signal.  When the entire signal one is trying to measure is equal to the manual adjustments one is making to measurements, it probably makes sense to put a LOT of scrutiny on the adjustments.  (This is a post from 7 years ago discussing these adjustments.  Note that these adjustments are less than current ones in the data base as they have been increased, though I cannot find a similar chart any more from the NOAA discussing the adjustments)
  3. The NOAA HAS made adjustments to US temperature data over the last few years that has increased the apparent warming trend.  These changes in adjustments have not been well-explained.  In fact, they have not really be explained at all, and have only been detected by skeptics who happened to archive old NOAA charts and created comparisons like the one below.  Here is the before and after animation (pre-2000 NOAA US temperature history vs. post-2000).  History has been cooled and modern temperatures have been warmed from where they were being shown previously by the NOAA.  This does not mean the current version  is wrong, but since the entire US warming signal was effectively created by these changes, it is not unreasonable to act for a detailed reconciliation (particularly when those folks preparing the chart all believe that temperatures are going up, so would be predisposed to treating a flat temperature chart like the earlier version as wrong and in need of correction. 1998changesannotated
  4. However, manual adjustments are not, as some skeptics seem to argue, wrong or biased in all cases.  There are real reasons for manual adjustments to data -- for example, if GPS signal data was not adjusted for relativistic effects, the position data would quickly get out of whack.  In the case of temperature data:
    • Data is adjusted for shifts in the start/end time for a day of measurement away from local midnight (ie if you average 24 hours starting and stopping at noon).  This is called Time of Observation or TOBS.  When I first encountered this, I was just sure it had to be BS.  For a month of data, you are only shifting the data set by 12 hours or about 1/60 of the month.  Fortunately for my self-respect, before I embarrassed myself I created a spreadsheet to monte carlo some temperature data and play around with this issue.  I convinced myself the Time of Observation adjustment is valid in theory, though I have no way to validate its magnitude  (one of the problems with all of these adjustments is that NOAA and other data authorities do not release the source code or raw data to show how they come up with these adjustments).   I do think it is valid in science to question a finding, even without proof that it is wrong, when the authors of the finding refuse to share replication data.  Steven Goddard, by the way, believes time of observation adjustments are exaggerated and do not follow NOAA's own specification.
    • Stations move over time.  A simple example is if it is on the roof of a building and that building is demolished, it has to move somewhere else.  In an extreme example the station might move to a new altitude or a slightly different micro-climate.  There are adjustments in the data base for these sort of changes.  Skeptics have occasionally challenged these, but I have no reason to believe that the authors are not using best efforts to correct for these effects (though again the authors of these adjustments bring criticism on themselves for not sharing replication data).
    • The technology the station uses for measurement changes (e.g. thermometers to electronic devices, one type of electronic device to another, etc.)   These measurement technologies sometimes have known biases.  Correcting for such biases is perfectly reasonable  (though a frustrated skeptic could argue that the government is diligent in correcting for new cooling biases but seldom corrects for warming biases, such as in the switch from bucket to water intake measurement of sea surface temperatures).
    • Even if the temperature station does not move, the location can degrade.  The clearest example is a measurement point that once was in the country but has been engulfed by development  (here is one example -- this at one time was the USHCN measurement point with the most warming since 1900, but it was located in an open field in 1900 and ended up in an asphalt parking lot in the middle of Tucson.)   Since urban heat islands can add as much as 10 degrees F to nighttime temperatures, this can create a warming signal over time that is related to a particular location, and not the climate as a whole.  The effect is undeniable -- my son easily measured it in a science fair project.  The effect it has on temperature measurement is hotly debated between warmists and skeptics.  Al Gore originally argued that there was no bias because all measurement points were in parks, which led Anthony Watts to pursue the surface station project where every USHCN station was photographed and documented.  The net result was that most of the sites were pretty poor.  Whatever the case, there is almost no correction in the official measurement numbers for urban heat island effects, and in fact last time I looked at it the adjustment went the other way, implying urban heat islands have become less of an issue since 1930.  The folks who put together the indexes argue that they have smoothing algorithms that find and remove these biases.  Skeptics argue that they just smear the bias around over multiple stations.  The debate continues.
  5. Overall, many mainstream skeptics believe that actual surface warming in the US and the world has been about half what is shown in traditional indices, an amount that is then exaggerated by poorly crafted adjustments and uncorrected heat island effects.  But note that almost no skeptic I know believes that the Earth has not actually warmed over the last 100 years.  Further, warming since about 1980 is hard to deny because we have a second, independent way to measure global temperatures in satellites.  These devices may have their own issues, but they are not subject to urban heat biases or location biases and further actually measure most of the Earth's surface, rather than just individual points that are sometimes scores or hundreds of miles apart.  This independent method of measurement has shown undoubted warming since 1979, though not since the late 1990's.
  6. As is usual in such debates, I find words like "fabrication", "lies",  and "myth" to be less than helpful.  People can be totally wrong, and refuse to confront their biases, without being evil or nefarious.

To these I will add a #7:  The notion that satellite results are somehow pure and unadjusted is just plain wrong.  The satellite data set takes a lot of mathematical effort to get right, something that Roy Spencer who does this work (and is considered in the skeptic camp) will be the first to tell you.  Satellites have to be adjusted for different things.  They have advantages over ground measurement because they cover most all the Earth, they are not subject to urban heat biases, and bring some technological consistency to the measurement.  However, the satellites used are constantly dieing off and being replaced, orbits decay and change, and thus times of observation of different parts of the globe change [to their credit, the satellite folks release all their source code for correcting these things].   I have become convinced the satellites, net of all the issues with both technologies, provide a better estimate but neither are perfect.

The 2014 Temperature Record No One Is Talking About

Depending on what temperature data set you look at **, or on your trust in various manual adjustments in these data sets ***, 2014 may have beaten the previous world temperature record by 0.02C.  Interestingly, the 0.02C rise over the prior record set four years ago would imply (using only these two data points which warmists seem to want to focus on) a temperature increase of 0.5C per century, a few tenths below my prediction but an order of magnitude below the alarmists' predictions for future trends.

Anyway, whether there was an absolute record or not, there was almost certainly a different temperature record set -- the highest divergence to date in the modern measured temperatures from what the computer models predicted.  The temperature increase for the past 5 years was a full 0.17C less than predicted, the largest gap yet for the models in forward-prediction mode (as opposed to when they are used to backcast history).


** There are four or five or more data sets, depending on how you count them.   There are 2 major satellite data sets and 2-3 ground based data sets.  The GISS ground data set generally gives the largest warming trends, while the satellite data sets give the least, but all show some warming over the last 30 or so years (though most of this warming was before 1999).

*** The data sets are all full of manual adjustments of various sorts.  All of these are necessary.  For surface stations, the measurement points move and change technology.  For the satellites, orbits and instruments shift over time.  The worrisome feature of all these adjustments is that they are large as compared to the underlying warming signal being measured, so small changes in the adjustments can lead to large changes in the apparent trend.  Skeptics often charge that the proprietors of land data sets are aggressive about including adjustments that increase the apparent trend but reluctant to add similar adjustments (eg for urban heat islands) that might reduce the trend.  As a result, most of the manual adjustments increase the trend.  There is actually little warming trend in the raw data, and it only shows up after the adjustments.  It may be total coincidence, but the database run by the most ardent warmist is the GISS and it has the highest trend.   The database run by the most skeptical is the UAH satellite database and it shows the smallest trend.  Hmm.

California Drought Update -- Not Even Close to Worst Drought Ever

There is little trend evidence anywhere that climate is getting -- pick the world -- weirder, more extreme, out of whack, whatever.  In particular, name any severe weather category you can imagine, and actual data in trend charts likely will not show any recent trend.

The reasons the average person on the street will swear you are a crazy denier for pointing such a thing out to them is that the media bombards them with news of nearly every 2+ sigma weather event, calling most of these relatively normal episodes as "the worst ever".

A great example is the California drought.  Here is the rolling average 5-year precipitation chart for California.  Find the worst drought "ever".


I know no one trusts anyone else's data in public debates, but you can make these charts yourself at the NOAA site, just go here:  The one record set was that 2013 had the lowest measured CA precipitation in the last century plus, so that was indeed a record bad year, but droughts are typically made up of multiple years of below average precipitation and by that measure the recent CA drought is the fourth or fifth worst.

By the way, Paul Homewood points out something that even surprised me and I try not to be susceptible to the mindless media bad news stampeded:  California rainfall this year was close to normal.  And, as you can see, there is pretty much no trend over the last century plus in California rainfall:



As discussed previously, let's add the proviso that rainfall is not necessarily the best metric of drought.  The Palmer drought index looks at moisture in soil and takes into account other factors like temperature and evaporation, and by that metric this CA drought is closer to the worst of the century, though certainly not what one would call unprecedented.  Also, there is a worsening trend in the Palmer data.



Update:  By the way, the fact that two measures of drought give us two different answers on the relative severity of the drought and on the trend in droughts is typical.   It makes a mockery of the pretense to certainty on these topics in the media.  Fortunately, I am not so invested in the whole thing that I can't include data that doesn't support my thesis.

What is Normal?

I titled my very first climate video "What is Normal," alluding to the fact that climate doomsayers argue that we have shifted aspects of the climate (temperature, hurricanes, etc.) from "normal" without us even having enough historical perspective to say what "normal" is.

A more sophisticated way to restate this same point would be to say that natural phenomenon tend to show various periodicities, and without observing nature through the whole of these cycles, it is easy to mistake short term cyclical variations for long-term trends.

A paper in the journal Water Resources Research makes just this point using over 200 years of precipitation data:

We analyze long-term fluctuations of rainfall extremes in 268 years of daily observations (Padova, Italy, 1725-2006), to our knowledge the longest existing instrumental time series of its kind. We identify multidecadal oscillations in extremes estimated by fitting the GEV distribution, with approximate periodicities of about 17-21 years, 30-38 years, 49-68 years, 85-94 years, and 145-172 years. The amplitudes of these oscillations far exceed the changes associated with the observed trend in intensity. This finding implies that, even if climatic trends are absent or negligible, rainfall and its extremes exhibit an apparent non-stationarity if analyzed over time intervals shorter than the longest periodicity in the data (about 170 years for the case analyzed here). These results suggest that, because long-term periodicities may likely be present elsewhere, in the absence of observational time series with length comparable to such periodicities (possibly exceeding one century), past observations cannot be considered to be representative of future extremes. We also find that observed fluctuations in extreme events in Padova are linked to the North Atlantic Oscillation: increases in the NAO Index are on average associated with an intensification of daily extreme rainfall events. This link with the NAO global pattern is highly suggestive of implications of general relevance: long-term fluctuations in rainfall extremes connected with large-scale oscillating atmospheric patterns are likely to be widely present, and undermine the very basic idea of using a single stationary distribution to infer future extremes from past observations.

Trying to work with data series that are too short is simply a fact of life -- everyone in climate would love a 1000-year detailed data set, but we don't have it.  We use what we have, but it is important to understand the limitations.  There is less excuse for the media that likes to use single data points, e.g. one storm, to "prove" long term climate trends.

A good example of why this is relevant is the global temperature trend.  This chart is a year or so old and has not been updated in that time, but it shows the global temperature trend using the most popular surface temperature data set.  The global warming movement really got fired up around 1998, at the end of the twenty year temperature trend circled in red.

click to enlarge


They then took the trends from these 20 years and extrapolated them into the future:

click to enlarge

But what if that 20 years was merely the upward leg of a 40-60 year cyclic variation?  Ignoring the cyclic functions would cause one to overestimate the long term trend.  This is exactly what climate models do, ignoring important cyclic functions like the AMO and PDO.

In fact, you can get a very good fit with actual temperature by modeling them as three functions:  A 63-year sine wave, a 0.4C per century long-term linear trend  (e.g. recovery from the little ice age) and a new trend starting in 1945 of an additional 0.35C, possibly from manmade CO2.Slide52

In this case, a long-term trend still appears to exist but it is exaggerated by only trying to measure it in the upward part of the cycle (e.g. from 1978-1998).


Why Do Climate Change Claims Consistently Get a Fact-Checker Pass?

It is almost impossible to read a media story any more about severe weather events without seeing some blurb about such and such event being the result of manmade climate change.  I hear writers all the time saying that it is exhausting to run the gauntlet of major media fact checkers, so why do they all get a pass on these weather statements?  Even the IPCC, which we skeptics think is exaggerating manmade climate change effects, refused to link current severe weather events with manmade CO2.

The California drought brings yet another tired example of this.  I think pretty much everyone in the media has operated from the assumption that the current CA drought is 1. unprecedented and 2. man-made. The problem is that neither are true.  Skeptics have been saying this for months, pointing to 100-year California drought data and pointing to at 2-3 other events in the pre-manmade-CO2 era that were at least as severed.  But now the NOAA has come forward and said roughly the same thing:

Natural weather patterns, not man-made global warming, are causing the historic drought parching California, says a study out Monday from federal scientists.

"It's important to note that California's drought, while extreme, is not an uncommon occurrence for the state," said Richard Seager, the report's lead author and professor with Columbia University's Lamont Doherty Earth Observatory. The report was sponsored by the National Oceanic and Atmospheric Administration. The report did not appear in a peer-reviewed journal but was reviewed by other NOAA scientists.

"In fact, multiyear droughts appear regularly in the state's climate record, and it's a safe bet that a similar event will happen again," he said.

The persistent weather pattern over the past several years has featured a warm, dry ridge of high pressure over the eastern north Pacific Ocean and western North America. Such high-pressure ridges prevent clouds from forming and precipitation from falling.

The study notes that this ridge — which has resulted in decreased rain and snowfall since 2011 — is almost opposite to what computer models predict would result from human-caused climate change.

There is an argument to be made that this drought was made worse by the fact that the low precipitation was mated with higher-than average temperatures that might be partially attributable to man-made climate change.  One can see this in the Palmer drought severity index, which looks at more factors than just precipitation.  While the last 3 years was not the lowest for rainfall in CA over the last 100, I believe the Palmer index was the lowest for the last 3 years of any period in the last 100+ years.  The report did not address this warming or attempt to attribute some portion of it to man, but it is worth noting that temperatures this year in CA were, like the drought, not unprecedented, particularly in rural areas (urban areas are going to be warmer than 50 years ago due to increasing urban heat island effect, which is certainly manmade but has nothing to do with CO2.)

Update:  By the way, note the article is careful to give several paragraphs after this bit to opponents who disagree with the findings.  Perfectly fine.  But note that this is the courtesy that is increasingly denied to skeptics when the roles are reversed.  Maybe I should emulate climate alarmists and be shouting "false balance!  the science is settled!"

Trend That is Not A Trend: Increase in Typhoons and Hurricanes

The science that CO2 is a greenhouse gas and causes some warming is hard to dispute.  The science that Earth is dominated by net positive feedbacks that increase modest greenhouse gas warming to catastrophic levels is very debatable.  The science that man's CO2 is already causing an increase in violent and severe weather is virtually non-existent.

Seriously, of all the different pieces of the climate debate, the one that is almost always based on pure crap are the frequent media statements linking manmade CO2 to some severe weather event.

For example, Coral Davenport in the New York Times wrote the other day:

As the torrential rains of Typhoon Hagupit flood thePhilippines, driving millions of people from their homes, the Philippine government arrived at a United Nationsclimate change summit meeting on Monday to push hard for a new international deal requiring all nations, including developing countries, to cut their use of fossil fuels.

It is a conscious pivot for the Philippines, one of Asia’s fastest-growing economies. But scientists say the nation is also among the most vulnerable to the impacts of climate change, and the Philippine government says it is suffering too many human and economic losses from the burning of fossil fuels....

A series of scientific reports have linked the burning of fossil fuels with rising sea levels and more powerful typhoons, like those that have battered the island nation.

It is telling that Ms. Davenport did not bother to link or name any of these scientific reports.  Even the IPCC, which many skeptics believe to be exaggerating manmade climate change dangers, refused in its last report to link any current severe weather events with manmade CO2.

Roger Pielke responded today with charts from two different recent studies on typhoon activity in the Phillipines.  Spot the supposed upward manmade trend.  Or not:




I am not a huge fan of landfalling cyclonic storm counts because whether they make landfall or not can be totally random and potentially disguise trends.  A better metric is the total energy of cyclonic storms, land-falling or not, where again there is no trend.

Via the Weather Underground, here is Accumulated Cyclonic Energy for the Western Pacific (lower numbers represent fewer cyclonic storms with less total strength):



And here, by the way, is the ACE for the whole globe:



Remember this when you see the next storm inevitably blamed on manmade global warming.  If anything, we are actually in a fairly unprecedented (in the last century and a half) hurricane drought.

The Science of Complex Systems -- Economics and Climate

I saw two statements written about economics over the weekend that could easily have been written about climate as well.  These are both complex systems where researchers try to link one output variable (e.g. global average surface temperatures or economic growth) to one input variable (e.g. CO2 or government spending).

Via Cafe Hayek, here is Bob Gelfond discussing Keynesian multiples

When it comes to the “evidence” demonstrating the magic of the Keynesian Multiplier, what we see, in fact, is merely careful curation of statistical flukes on a grand scale over decades. Economist Ryan Murphy, who runs a project called that attempts to catalog scholarly measurements of the Keynesian Multiplier, has categorized and analyzed 128 papers on the subject. Only four papers even attempt to include this kind of statistical test, and none of these validate the original results, meaning simply that none of them prove the Keynesian Multiplier actually leads to more dollar-for-dollar economic growth. And this is after these models are ginned up to make their theory look as good as possible. If attempts to employ macroeconomics purport to be science, they must boldly make predictions about the future, not rummage around for convenient data from the past. But no peddler of the Keynesian Multiplier has been able to make demonstrable predictions borne out by the test of time.

Morgan Housel on economic data, but applies to climate without changing a word.

Ideally we’d have 500 years of unimpeachably perfect data. In reality we have about 50 years of so-so data. If we had the former, we’d learn that so much of what we’ve learned from the latter is wrong and incomplete.

Update:  Here is a third bit from Arnold Kling in the same vein:

Sometimes, I think that there are macroeconomists (Krugman is not the only one) for whom there is no path of economic variables that could ever contradict their point of view. They remind me of the climate scientists who tell us that Buffalo’s Snowvember came from global warming.

Macroeconomics is infinitely confirmable because of its high causal density and lack of controlled experiments. The macroeconomist has enough interpretative degrees of freedom to twist any pattern of economic activity to fit his or her priors.


Illustrating Pollution Stories with Steam Plumes

Readers will know of my pet peeve on this issue.  It turns out this has come up as a viewer complaint at the BBC several times and they actually have a policy on it, though like many media organizations they don't consistently follow their own guide.

You can see many examples simply by searching google images for "air pollution".  The people riding bikes with masks are in actual pollution.  The rest of the photos on the first page are mainly steam plumes.  Note how the photographers like to catch the steam at dusk or backlit so they look dark and sortof smokey.

click to enlarge

Painting Your Intellectual Opponents as Psychologically Defective

Perhaps some of you have seen studies knocking about from time to time that attempt to correlate one or another political position with various psychological or mental deficiencies.  Probably the most common is "________ (fill in the blank, I have seen this study for both Conservatives and Liberals) have lower IQ or are less educated or more gullible or whatever than their intellectual opponents.  Most folks in the mainstream, fortunately, treat this as the unserious biased ad hominem attack that it is -- it should hardly be a surprise that the folks who look the best in all these studies miraculously match the political views of those doing the study.

However, for those of you who don't follow the climate debate, you may not know that there is a cottage industry among the alarmist / warmist community that cranks out studies that say that skeptics are mentally defective in some way.  I kid you not.  I won't get into it, because those not in the climate debate won't care much and those in the debate have seen this stuff debated to death.  But I thought those of you out of the loop might like to see an example.

A guy named Stephan Lewandowsky has released a series of really egregiously-structured studies around the general theme of climate skeptics being susceptible to conspiracy theories, or conspiracy "ideation" as he puts it.  He has "proved" this in the past by offering a mix of people on the Left and Right a list of conspiracy theories mainly held by people on the Right (e.g. Obama birth certificate) while leaving out almost any of the common conspiracy theories held by the Left.  Then he asks these people which theories they believe, and Surprise!  People on the Right, who overlap a lot with skeptics, believe Rightish conspiracy theories more than do people on the Left. So thus climate skeptics are what they are because they are people who are more susceptible than average to conspiracy ideation.  Yes, this study is as stupid as it sounds -- actually it is more stupid because he did it via Internet poll advertised mainly on alarmist blogs with no controls for people submitting false flag answers.  And like most climate studies, he got some basic statistical calculations wrong.

Anyway, his new study is out and it is just as awesome in its dedication to fail as his prior work

One known element of conspiratorial thinking is its ‘self-sealing’ quality (Keeley 1999, Bale 2007, Sunstein and Vermeule 2009), whereby evidence against a conspiratorial belief is re-interpreted as evidencefor that belief. In the case of ‘climategate’, this self-sealing nature ofconspiratorial belief became evident after the scientists in question wereexonerated by nine investigations in two countries (including various parliamentary and government committees in the U.S. and U.K.; see table1), when those exonerations were re-branded as a ‘whitewash.’ This ‘whitewash’ response can be illustrated by U.S. Representative Sensenbrennerʼs published response to the EPAʼs endangerment finding.

This so grossly oversimplifies the issues involved as to be breathtaking.  Only the most tightly sealed of echo chambers could possible pass this work on to publication.

HydroInfra: Scam! Investment Honeypot for Those Who Also Wanted To Ban DiHydrogen Monoxide

I got an email today from some random Gmail account asking me to write about HyrdoInfra.  OK.  The email begins: "HydroInfra Technologies (HIT) is a Stockholm based clean tech company that has developed an innovative approach to neutralizing carbon fuel emissions from power plants and other polluting industries that burn fossil fuels."

Does it eliminate CO2?  NOx?  Particulates?  SOx?  I actually was at the bottom of my inbox for once so I went to the site.  I went to this applications page.  Apparently, it eliminates the "toxic cocktail" of pollutants that include all the ones I mentioned plus mercury and heavy metals.  Wow!  That is some stuff.

Their key product is a process for making something they call "HyrdroAtomic Nano Gas" or HNG.  It sounds like their PR guys got Michael Crichton and JJ Abrams drunk in a brainstorming session for pseudo-scientific names.

But hold on, this is the best part.  Check out the description of HNG and how it is made:

Splitting water (H20) is a known science. But the energy costs to perform splitting outweigh the energy created from hydrogen when the Hydrogen is split from the water molecule H2O.

This is where mainstream science usually closes the book on the subject.

We took a different approach by postulating that we could split water in an energy efficient way to extract a high yield of Hydrogen at very low cost.

A specific low energy pulse is put into water. The water molecules line up in a certain structure and are split from the Hydrogen molecules.

The result is HNG.

HNG is packed with ‘Exotic Hydrogen’

Exotic Hydrogen is a recent scientific discovery.

HNG carries an abundance of Exotic Hydrogen and Oxygen.

On a Molecular level, HNG is a specific ratio mix of Hydrogen and Oxygen.

The unique qualities of HNG show that the placement of its’ charged electrons turns HNG into an abundant source of exotic Hydrogen.

HNG displays some very different properties from normal hydrogen.

Some basic facts:

  • HNG instantly neutralizes carbon fuel pollution emissions
  • HNG can be pressurized up to 2 bars.
  • HNG combusts at a rate of 9000 meters per second while normal Hydrogen combusts at a rate 600 meters per second.
  • Oxygen values actually increase when HNG is inserted into a diesel flame.
  • HNG acts like a vortex on fossil fuel emissions causing the flame to be pulled into the center thus concentrating the heat and combustion properties.
  • HNG is stored in canisters, arrayed around the emission outlet channels. HNG is injected into the outlets to safely & effectively clean up the burning of fossil fuels.
  • The pollution emissions are neutralized instantly & safely with no residual toxic cocktail or chemicals to manage after the HNG burning process is initiated.

Exotic Hyrdrogen!  I love it.  This is probably a component of the "red matter" in the Abrams Star Trek reboot.  Honestly, someone please tell me this a joke, a honeypot for mindless environmental activist drones.    What are the chemical reactions going on here?  If CO2 is captured, what form does it take?  How does a mixture of Hydrogen and Oxygen molecules in whatever state they are in do anything with heavy metals?  None of this is on the website.   On their "validation" page, they have big labels like "Horiba" that look like organizations thave somehow put their impremature on the study.  In fact, they are just names of analytical equipment makers.  It's like putting "IBM" in big print on your climate study because you ran your model on an IBM computer.

SCAM!  Honestly, when you see an article written to attract investment that sounds sort of impressive to laymen but makes absolutely no sense to anyone who knows the smallest about of Chemistry or Physics, it is an investment scam.

But they seem to get a lot of positive press.  In my search of Google, everything in the first ten pages or so are just uncritical republication of their press releases in environmental and business blogs.   You actually have to go into the comments sections of these articles to find anyone willing to observe this is all total BS.   If you want to totally understand why the global warming debate gets nowhere, watch commenter Michael at this link desperately try to hold onto his faith in HydroInfra while people who actually know things try to explain why this makes no sense.

Update:  If you want an actual nano-material that absorbs various pollutants, this may be one.

Listening to California Parks People Discuss Climate Change

Some random highlights:

  • I watched a 20 minute presentation in which a woman from LA parks talked repeatedly about the urban heat island being a result of global warming
  • I just saw that California State Parks, which is constantly short of money and has perhaps a billion dollars in unfunded maintenance needs, just spent millions of dollars to remove a road from a beachfront park based solely (they claimed) based on projections that 55 inches of sea level rise would cause the road to be a problem.  Sea level has been rising 3-4mm a year for over 150 years and even the IPCC, based on old much higher temperature increase forecasts, predicted about a foot of rise.
  • One presenter said that a 3-5C temperature rise over the next century represent the low end of reasonable forecasts.  Most studies of later are showing a climate sensitivity of 1.5-2.0 C (I still predict 1C) with warming over the rest of the century of about 1C, or about what we saw last century
  • I watched them brag for half an hour about spending tons of extra money on make LEED certified buildings.  As written here any number of times, most LEED savings come through BS gaming of the rules, like putting in dedicated electric vehicle parking sites (that do not even need a charger to get credit).  In a brief moment of honesty, the architect presenting admitted that most of the LEED score for one building came from using used rather than new furniture in the building.
  • They said that LEED buildings were not any more efficient than most other commercial buildings getting built, just a matter of whether you wanted to pay for LEED certification -- it was stated that the certification was mostly for the plaque.  Which I suppose is fine for private businesses looking for PR, but why are cash-strapped public agencies doing it?

And I'm Anti-Science?

Would all those folks who so revel in calling folks like me "anti-science" (Dr. Michael Mann being foremost among them) please stop using cooling tower steam plumes as an illustration of CO2 production?  Not only is steam not pollution (though it sortof kindof can be made to look like it if you photoshop it right), but the cooling towers so often featured in these shots are not even emitting combustion products at all.

I Think Matt Ridley Just Quoted Me

Matt Ridley gave the keynote today and said something like, "as someone once said, Greenpeace offices should have John D Rockefeller's picture on the wall because he did more than anyone else to save the whales."    Hmmmm.  Wonder who has been saying that?

Here as early as almost a decade ago

Here I am in Forbes

Where's Coyote?

Well it has been a busy 10 days for travel.  Last weekend my wife and I were at Harvard for our 25th anniversary of graduating from the business school there.   The way the b-school taught at the time, they basically locked 90 people together (a "section") in the same room for a year and threw teachers and course material at them.  I may have spent more time in a room with those 90 people than I spent in the same room with my dad growing up.  So you get to know them pretty well.  It was fun seeing everybody, though intimidating given all the folks my age running Fortune 50 companies or cashing out billion dollar startups.

After that, I went to Bozeman early this week and discussed free-market options for reforming the National Park Service at an event hosted by PERC, the Property and Environment Research Center.  On Tuesday we went into Yellowstone and met with the Superintendent there, who had also run the whole agency for about a year.  A lot of the discussion was about sustainability - financially.  The NPS raises less than 10% of its revenue from visitors, and so must constantly fight with Congress for cash.   One problem is that Yellowstone (perhaps their premier park) charges just $25 per vehicle for a one week admission.  This is insane.  We have tiny state parks in Arizona with one millionth of the appeal that fill the park despite a $20 a day entrance fee.  And the NPS (or really Congress) takes every opportunity to discount this already absurdly low rate even further.  You can get into all the parks for the rest of your life for a single $10 payment with the Senior pass.  This essentially gives free entry to their largest visitor demographic.

Today I am in Houston for a sort of climate skeptics' conference.  If you are in the area and the agenda looks interesting, they are still selling admissions (I think) for $75 for the two day event at the Hyatt downtown.   Rick Perry is speaking tonight, and that is supposed to be a draw I guess but I am actually skipping that and focusing on the scientists they have through the day.  Hopefully it is interesting, but I am also a conference skeptic so we will see.

Testing Blog Cross-Post 2


Testing Blog Cross-Post

I couldn't get to automatically cross-post (it can only recognize one WordPress account at a time) so now I am trying  I need to use it for a while but despite being a long-time IFTTT fan, Zapier seems to have a going for it.

Thank God For Scientists: "Unexpected Link Between Solar Activity and Climate Change"

Without scientists, we would never be apprised of the fact that the behavior of the sun affects how warm or cold it is on Earth (emphasis added)

For the first time, a research team has been able to reconstruct the solar activity at the end of the last ice age, around 20 000–10 000 years ago, by analysing trace elements in ice cores in Greenland and cave formations from China. During the last glacial maximum, Sweden was covered in a thick ice sheet that stretched all the way down to northern Germany and sea levels were more than 100 metres lower than they are today, because the water was frozen in the extensive ice caps. The new study shows that the sun’s variation influences the climate in a similar way regardless of whether the climate is extreme, as during the Ice Age, or as it is today.

“The study shows an unexpected link between solar activity and climate change. It shows both that changes in solar activity are nothing new and that solar activity influences the climate, especially on a regional level. Understanding these processes helps us to better forecast the climate in certain regions”, said Raimund Muscheler, Lecturer in Quaternary Geology at Lund University and co-author of the study.

My snarky tone is a bit unfair here.  While the sun seems an obvious candidate as a major climate driver, changes in its actual energy hitting the Earth have always appeared small compared to what would be needed to explain observed temperature changes.  This team hypothesizes that the changes in the sun's output have effects on atmospheric circulation that have a larger than expected impact on temperatures.  Henrik Svensmark explains it a different way, hypothesizing that cloud formation is heavily influenced by cosmic rays, and higher solar activity tends to shield the Earth from cosmic rays, thus reducing cloud formation and increasing temperatures.

Skeptics find this sudden realization that the sun affects climate to be kind of funny, since they have argued for years that higher temperatures in the late 20th century have coincided with a very active sun, probably more active than it has been in hundreds of years.   Climate alarmists have denied any influence to the sun.  Sun deniers!  This absolutist stance may seem odd, given that most skeptics (despite what is said of us) actually accept some amount of warming from CO2, but here are these folks who wrap themselves in the mantle of science that deny any effect from the sun?  The problem that warmists have is that higher climate sensitivities, on the order of 3 degrees C per doubling of CO2, greatly over-predict past warming (as I demonstrate in my videos, see around the 59 minute mark).  If anything else whatsoever other than CO2 caused one iota of the warming over the last 50 years, then this over-prediction just gets worse.  In fact, warmists have to assume crazy high levels of aerosol cooling -- that go beyond what most of the science supports -- to make their forecasts work looking backwards.

Scott Sumner Explains a Lot of Climate Alarmism, Without Discussing Climate

Scott Sumner is actually discussing discrimination, and how discrimination is often "proven" in social studies

The economy operates in very subtle ways, and often when I read academic studies of issues like discrimination, the techniques seem incredibly naive to me. They might put in all the attributes of male and female labor productivity they can think of, and then simply assume than any unexplained residual must be due to "discrimination." And they do this in cases where there is no obvious reason to assume discrimination. It would be like a scientist assuming that magicians created a white rabbit out of thin air, at the snap of their fingers, because they can't think of any other explanation of how it got into the black hat!

Most alarming climate forecasts are based on the period from 1978 to 1998.  During this 20 year period world temperatures rose about a half degree C.  People may say they are talking about temperature increases since 1950, but most if not all of those increases occurred from 1978-1998.  Temperatures were mostly flat or down before and since.

A key, if not the key, argument for CO2-driven catastrophic warming that is based on actual historic data (rather than on theory or models) is that temperatures rose in this 20 year period farther and faster than would be possible by any natural causes, and thus must have been driven by man-made CO2.  Essentially what scientists said was, "we have considered every possible natural cause of warming that we can think of, and these are not enough to cause this warming, so the warming must be unnatural."  I was struck just how similar this process was to what Mr. Sumner describes.  Most skeptics, by the way, agree that some of this warming may have been driven by manmade CO2 but at the same time argue that there were many potential natural effects (e.g. ocean cycles) that were not considered in this original analysis.

Trend That Is Not A Trend: Wildfires (At Least Not This Year)

From the White House:

click to enlarge

From the Federal Government's National Inter-agency Fire Center wildfire tracking page today

click to enlarge


The White House letter demonstrates the behavior that drives me crazy and caused me to start this feature in the first place.  They point to 14 fires in California and imply that this proves some kind of trend.  But how can an individual data point say anything about a trend?  In fact, as you can see above, there almost 50,000 wildfires by this point each year.  So what does the existence of 14 mean, one way or another, in establishing a trend?

Just to show that I don't underestimate the impact of fire, one of these two fires referenced in the White House letter is actually threatening my business near Burney, California and has caused us substantial losses due to lost revenue (for some odd reason people don't like to come out to a park when the air is filled with smoke and ash -- go figure).



PS -- There is an upward trend in the data vs. the 1950s and 1960s which is likely tied somewhat to climate but also somewhat to forest management practices.  Academics have had trouble separating the two.


Reconciling Seemingly Contradictory Climate Claims

At Real Science, Steven Goddard claims this is the coolest summer on record in the US.

The NOAA reports that both May and June were the hottest on record.

It used to be the the media would reconcile such claims and one might learn something interesting from that reconciliation, but now all we have are mostly-crappy fact checks with Pinocchio counts.  Both these claims have truth on their side, though the NOAA report is more comprehensively correct.  Still, we can learn something by putting these analyses in context and by reconciling them.

The NOAA temperature data for the globe does indeed show May and June as the hottest on record.  However, one should note a couple of things

  • The two monthly records do not change the trend over the last 10-15 years, which has basically been flat.  We are hitting records because we are sitting on a plateau that is higher than the rest of the last century (at least in the NOAA data).  It only takes small positive excursions to reach all-time highs
  • There are a number of different temperature data bases that measure the temperature in different ways (e.g. satellite vs. ground stations) and then adjust those raw readings using different methodologies.  While the NOAA data base is showing all time highs, other data bases, such as satellite-based ones, are not.
  • The NOAA database has been criticized for manual adjustments to temperatures in the past which increase the warming trend.  Without these adjustments, temperatures during certain parts of the 1930's (think: Dust Bowl) would be higher than today.  This was discussed here in more depth.  As is usual when looking at such things, some of these adjustments are absolutely appropriate and some can be questioned.  However, blaming the whole of the warming signal on such adjustments is just wrong -- satellite data bases which have no similar adjustment issues have shown warming, at least between 1979 and 1999.

The Time article linked above illustrated the story of these record months with a video partially on wildfires.  This is a great example of how temperatures are indeed rising but media stories about knock-on effects, such as hurricanes and fires, can be full of it.  2014 has actually been a low fire year so far in the US.

So the world is undeniably on the warm side of average (I won't way warmer than normal because what is "normal"?)  So how does Goddard get this as the coolest summer on record for the US?

Well, the first answer, and it is an important one to remember, is that US temperatures do not have to follow global temperatures, at least not tightly.  While the world warmed 0.5-0.7 degrees C from 1979-1999, the US temperatures moved much less.  Other times, the US has warmed or cooled more than the world has.  The US is well under 5% of the world's surface area.  It is certainly possible to have isolated effects in such an area.  Remember the same holds true the other way -- heat waves in one part of the world don't necessarily mean the world is warming.

But we can also learn something that is seldom discussed in the media by looking at Goddard's chart:

click to enlarge

First, I will say that I am skeptical of any chart that uses "all USHCN" stations because the number of stations and their locations change so much.  At some level this is an apples to oranges comparison -- I would be much more comfortable to see a chart that looks at only USHCN stations with, say, at least 80 years of continuous data.  In other words, this chart may be an artifact of the mess that is the USHCN database.

However, it is possible that this is correct even with a better data set and against a backdrop of warming temperatures.  Why?  Because this is a metric of high temperatures.  It looks at the number of times a data station reads a high temperature over 90F.  At some level this is a clever chart, because it takes advantage of a misconception most people, including most people in the media have -- that global warming plays out in higher daytime high temperatures.

But in fact this does not appear to be the case.  Most of the warming we have seen over the last 50 years has manifested itself as higher nighttime lows and higher winter temperatures.  Both of these raise the average, but neither will change Goddard's metric of days above 90F.  So it is perfectly possible Goddard's chart is right even if the US is seeing a warming trend over the same period.  Which is why we have not seen any more local all-time daily high temperature records set recently than in past decades.  But we have seen a lot of new records for high low temperature, if that term makes sense.  Also, this explains why the ratio of daily high records to daily low records has risen -- not necessarily because there are a lot of new high records, but because we are setting fewer low records.  We can argue about daytime temperatures but nighttime temperatures are certainly warmer.

This chart shows an example with low and high temperatures over time at Amherst, MA  (chosen at random because I was speaking there).  Note that recently, most warming has been at night, rather than in daily highs.

Computer Modeling as "Evidence"

The BBC has decided not to every talk to climate skeptics again, in part based on the "evidence" of computer modelling

Climate change skeptics are being banned from BBC News, according to a new report, for fear of misinforming people and to create more of a "balance" when discussing man-made climate change.

The latest casualty is Nigel Lawson, former London chancellor and climate change skeptic, who has just recently been barred from appearing on BBC. Lord Lawson, who has written about climate change, said the corporation is silencing the debate on global warming since he discussed the topic on its Radio 4 Today program in February.

This skeptic accuses "Stalinist" BBC of succumbing to pressure from those with renewable energy interests, like the Green Party, in an editorial for the Daily Mail.

He appeared on February 13 debating with scientist Sir Brian Hoskins, chairman of the Grantham Institute for Climate Change at Imperial College, London, to discuss recent flooding that supposedly was linked to man-made climate change.

Despite the fact that the two intellectuals had a "thoroughly civilized discussion," BBC was "overwhelmed by a well-organized deluge of complaints" following the program. Naysayers harped on the fact that Lawson was not a scientist and said he had no business voicing his opinion on the subject.


Among the objections, including one from Green Party politician Chit Chong, were that Lawson's views were not supported by evidence from computer modeling.

I see this all the time.  A lot of things astound me in the climate debate, but perhaps the most astounding has been to be accused of being "anti-science" by people who have such a poor grasp of the scientific process.

Computer models and their output are not evidence of anything.  Computer models are extremely useful when we have hypotheses about complex, multi-variable systems.  It may not be immediately obvious how to test these hypotheses, so computer models can take these hypothesized formulas and generate predicted values of measurable variables that can then be used to compare to actual physical observations.

This is no different (except in speed and scale) from a person in the 18th century sitting down with Newton's gravitational equations and grinding out five years of predicted positions for Venus (in fact, the original meaning of the word "computer" was a human being who ground out numbers in just his way).  That person and his calculations are the exact equivalent of today's computer models.  We wouldn't say that those lists of predictions for Venus were "evidence" that Newton was correct.  We would use these predictions and compare them to actual measurements of Venus's position over the next five years.  If they matched, we would consider that match to be the real evidence that Newton may be correct.

So it is not the existence of the models or their output that are evidence that catastrophic man-made global warming theory is correct.  It would be evidence that the output of these predictive models actually match what plays out in reality.  Which is why skeptics think the fact that the divergence between climate model temperature forecasts and actual temperatures is important, but we will leave that topic for other days.

The other problem with models

The other problem with computer models, besides the fact that they are not and cannot constitute evidence in and of themselves, is that their results are often sensitive to small changes in tuning or setting of variables, and that these decisions about tuning are often totally opaque to outsiders.

I did computer modelling for years, though of markets and economics rather than climate.  But the techniques are substantially the same.  And the pitfalls.

Confession time.  In my very early days as a consultant, I did something I am not proud of.  I was responsible for a complex market model based on a lot of market research and customer service data.  Less than a day before the big presentation, and with all the charts and conclusions made, I found a mistake that skewed the results.  In later years I would have the moral courage and confidence to cry foul and halt the process, but at the time I ended up tweaking a few key variables to make the model continue to spit out results consistent with our conclusion.  It is embarrassing enough I have trouble writing this for public consumption 25 years later.

But it was so easy.  A few tweaks to assumptions and I could get the answer I wanted.  And no one would ever know.  Someone could stare at the model for an hour and not recognize the tuning.

Robert Caprara has similar thoughts in the WSJ (probably behind a paywall)  Hat tip to a reader

The computer model was huge—it analyzed every river, sewer treatment plant and drinking-water intake (the places in rivers where municipalities draw their water) in the country. I'll spare you the details, but the model showed huge gains from the program as water quality improved dramatically. By the late 1980s, however, any gains from upgrading sewer treatments would be offset by the additional pollution load coming from people who moved from on-site septic tanks to public sewers, which dump the waste into rivers. Basically the model said we had hit the point of diminishing returns.

When I presented the results to the EPA official in charge, he said that I should go back and "sharpen my pencil." I did. I reviewed assumptions, tweaked coefficients and recalibrated data. But when I reran everything the numbers didn't change much. At our next meeting he told me to run the numbers again.

After three iterations I finally blurted out, "What number are you looking for?" He didn't miss a beat: He told me that he needed to show $2 billion of benefits to get the program renewed. I finally turned enough knobs to get the answer he wanted, and everyone was happy...

I realized that my work for the EPA wasn't that of a scientist, at least in the popular imagination of what a scientist does. It was more like that of a lawyer. My job, as a modeler, was to build the best case for my client's position. The opposition will build its best case for the counter argument and ultimately the truth should prevail.

If opponents don't like what I did with the coefficients, then they should challenge them. And during my decade as an environmental consultant, I was often hired to do just that to someone else's model. But there is no denying that anyone who makes a living building computer models likely does so for the cause of advocacy, not the search for truth.