The flying car revolution will never happen

One of science fiction’s greatest mistakes is the flying car. And that icon of the future is under further threat from a real technological revolution, the driverless car.

My mental image of a flying car is shaped heavily by their depiction in the Fifth Element, in which Bruce Willis drives a yellow taxi that is, cosmetically, an ordinary car that happens to drive on thin air. He navigates traffic lanes that form a 3D lattice amongst buildings so tall that we rarely see the ground. A close second in my mental imagery is the “hover converted” DeLorean1 from Back to the Future part II, which we see navigating a “skyway” in the far-off year of 2015.

It didn’t happen, of course. There are certainly people trying to make it happen, but clearly they haven’t made much of a dent in the way our transport systems actually operate. Articles on the subject of flying cars (e.g. this one, and this one) often start by pointing out the obvious, and end by wistfully suggesting “maybe some day”.

No. Here’s my prediction: the flying car revolution will never happen. Not in a decade, nor a century, nor a millennium. The flying car — as portrayed in science fiction, and distinct from today’s commercial passenger aircraft — is a fatally flawed concept. That’s not to say you can’t make one; you just can’t make society adopt them. They will never be a significant component of our transport network.


There are several reasons. The first to spring to mind first is safety. Surface driving is already a significant cause of death; drivers already fail at the delicate art of steering in two dimensions, let alone three. When we do travel by air, we appreciate that our pilots are somewhat more qualified than your average tailgating, drink-driving arseclown who has no understanding of risk. And even when you’re not a tailgating, drink-driving arseclown, driving is still inherently risky.

Would you like to see what a flying car collision looks like? Observe from afar, because there’s no such thing as a “fender bender” in the air. There’s no “five star” safety rating. Seat belts and airbags won’t save you. If you lose control, you’re simply going to die. And in a populated area, people around you are going to die too, not to mention the property damage.

Some quick risk analysis is sobering. The probability (0-1) of something going wrong is bound to be higher. The consequences (measured in dollars or lives) are certainly much worse. We can multiply these to get a quantity called “risk” (also in dollars or lives), which you can think of as the expected cost per flying car, on average, if many people owned them. Since both factors are much higher with flying cars, the risk is catastrophic.


And calculating the probability of an “accident” avoids another very serious problem: what about deliberate crashes? What about criminality, or terrorism? How can you even begin to police a “skyway”? The term “flying car” belies the fact that this thing isn’t just a car but a missile. Should we install automated air-defence turrets on parliament, banks, hospitals, schools, apartment blocks, etc.? We must. If we are not prepared to shoot down flying cars, then inevitably criminals and extremists will use them, whether in a kamikaze attack, or as a remote-piloted weapon. And their targets will always be high-value ones.

Perhaps manufacturers can design safeguards to prevent collisions, and/or prevent entry into unauthorised airspace. But that won’t stop anyone with an aptitude for taking things apart.

And if we are prepared to shoot down flying cars, would you get in one? Moreover, the air defences themselves might prove a tempting weapon for criminals and terrorists. Feeling safe yet?

Physics and fuel efficiency

Flying cars from science fiction generally rely on as-yet undiscovered physical phenomena to keep them airborne. Sometimes “anti-gravity” is mentioned, a force that simply doesn’t exist as far as the current pool of scientific evidence indicates.

Even if anti-gravity were to exist, it would not necessarily be of any practical use. Hypothesised “exotic matter” could have negative mass, ergo negative, repulsive gravity. But it’s Earth’s gravity that matters, not the car’s. The “acceleration due to gravity” near the Earth’s surface is the same for any falling object, irrespective of mass (if we ignore friction). An exotic object with negative mass, even if it were possible, would still just fall downwards like everything else.

Magnets? Well, no. Although magnetic levitation exists (see diamagnetism, as used in maglev trains) there’s a significant difference between levitating a few millimetres above a superconductor and actually flying. You would need an implausibly powerful magnet to hold a car-sized object tens of metres off the ground, and if you had such a magnet, it would probably destroy everything around it. You can’t just tailor a magnetic field to only apply to one specific object. And the ultimate reason for the total futility of this idea: you still need a surface-bound vehicle to hold the magnet (or superconductor) underneath your flying car. What would be the point?2

Obviously, we do have a few real ways to keep something airborne. Balloons use buoyancy, but they are large, slow, and difficult to manoeuvre. Rockets use a controlled explosion, but this lasts for a matter of seconds. The most plausible way to create an actual flying car is as a scaled-down plane or helicopter, with spinning blades and aerofoils to push down on the air.

But “anti-gravity” is used in science fiction to get around a huge problem with aircraft — their fuel consumption. In the real world, fighting gravity consumes energy. Continuously. A surface car needs energy only to overcome friction and inertia. A flying car needs large amounts of energy simply to stay up, on top of the energy needed to actually move it from point A to point B. And in the end, the point A and point B that you’re travelling between are both on the ground, or at least connected to it.

(A side note: there is the interesting phenomenon of electrohydrodynamics, which can create lift by making charged particles push air molecules, with no explosions or moving parts needed. But even this doesn’t get around the problem; it still requires very large energy input.)

So why are you burning up all that jet fuel3 just to keep above the surface, when you could be cruising along the surface at a fraction of the price?

Traffic congestion is perhaps the one genuine reason people might have for taking to the air. It’s certainly tempting to imagine going over the top of all those suckers stuck in gridlock on the bitumen.


But there’s a problem with this picture too. While you’re flying over all the suckers stuck in gridlock on the bitumen, it may occur to you to ask why they aren’t flying too. Consider this paradox: if everyone is flying, by definition there is no surface traffic, ergo no surface gridlock, so then why is anyone flying?

Flying cars are going to be inherently more expensive than their surface counterparts. If we do overcome all the safety and security issues, it’s going to be thanks to some pretty fantastic engineering. That costs an awful lot of money up front, which needs to be recovered in sales. Also, as mentioned, there’s the fuel. And then there’s the servicing, similarly expensive due to the extreme life-and-death importance of keeping the vehicle running. And speaking of extreme life-and-death matters, there are the insurance premiums, if someone is crazy enough to sell you insurance at all.

It all adds up to a fanciful luxury for the vast majority of people. It would be fantastic, we’d all say, right up until we see the number of zeros in the price tag. It would be fantastic, but it’s just not worth it.

Furthermore, getting back to the paradox above, the uptake of flying cars in itself discourages further uptake (the opposite of many other technologies). Every time a person chooses to fly, that’s one less surface vehicle, meaning less congestion. Every person who uses a flying car reduces the incentive for everyone else to do so.

Nonetheless, you might imagine a situation where (a) the population continues to increase more or less boundlessly, and (b) the government makes fewer and fewer investments in surface infrastructure in recognition of increasing numbers of people with flying cars. Perhaps everyone would use a flying car eventually.

But even given that we’ve somehow solved the safety and security issues, I still think this scenario is highly unlikely in any reasonably democratic society. Governments will spend money on infrastructure (whether roads or public transport) because these are tangible things that voters will easily understand and use. Infrastructure makes for compelling election promises, and although it’s a short-term hit to the budget, it’s often easy to justify in real economic terms. To abandon infrastructure spending would be to abandon large numbers of voters who can’t afford the costs of flying.

Indeed, in a hypothetical city that already relies on flying cars, there would be economic pressure to go the other way — to develop efficient public infrastructure in order to minimise costs. Large/dense metropolises tend to have extensive public transport networks, because as the population density goes up, the cost of public transport per person goes down. The cost of flying cars does not.


But even congestion and commute times may not be so much of an issue in the future. Driverless cars represent a rather different and much more realistic kind of revolution.

This innovation could dramatically improve the efficiency of our road networks. On the roads we have constraints: the speed limit, the distance from the car in front, the lane widths, etc. We need these because of our general human imprecision, our slow reaction times, our reliance on mostly a single sense for driving (our eyesight), our blind spots while driving, and our inability to make decisions based on large amounts of sensory information at once. It’s also essentially impossible for a human driver to see what’s happening along alternate routes.

Driverless cars, in principle, have none of these problems. They can be faster and safer and more efficient. They can, in principle, perform safely in situations that would be dangerous for a human driver. (I only say “in principle” because it’s a matter of engineering quality. It may take a while to develop driverless cars to this point, but there’s nothing fundamentally standing in the way.)

To do this, they can take advantage of sensory data that humans simply don’t have — sonar, radar and lidar — to model their surroundings in a level of detail many times beyond our own mental capabilities (which are really very limited in rapidly-changing situations).

Software and hardware can react in a tiny fraction of a second, so driverless cars can safely leave much less buffer space. They can also make the best decision on which route to take based on real-time measurements of traffic density (provided by some external source). As a result, we could squeeze a lot more of them onto existing roads, increasing the total number of trips possible with the same amount of infrastructure.

Many people are doubtless nervous about giving up control of their vehicles, but as discussed, human driving is hardly safe as it is. In making a driverless car safer than a human driver (safer even than you), the bar isn’t really that high. Safety will become one of the principal arguments in favour of driverless cars, not against them. It’s just a matter of design, testing and time. (I don’t doubt there will be accidents, but it’s the accident rate that we must focus on.)

Driverless cars also facilitate cheap, automated taxi fleets, which may allow a lot of people to get by without their own cars at all. No more parking, refuelling, servicing, insurance or licensing (all of which are taken care of for you). No more fines and tickets. No more traffic police, except perhaps for the few DIY holdouts. Unlike flying cars, automated taxis would be a self-reinforcing technology. There’s no huge up-front to commuters, and the more there are, the shorter your waiting times will be, so the more likely you will be to use them.

And when you’re commuting in a driverless car, that need not be wasted time. You could be working on a laptop/tablet, reading, teleconferencing, eating a meal or even just sleeping. Given that you can fill in the commute with useful activities, the actual time it takes may not be so much of an issue any more.

It’s not just that driverless cars are more useful and realistic than flying cars. Once we have driverless cars, the arguments for flying cars will practically vanish altogether.

So, science fiction, let’s put one of those ideas out of its misery.

  1. It’s also a time machine, but that’s strangely unimportant in this context. []
  2. Okay, perhaps you could convince the government to build a grid of super-powerful magnets to keep your flying car aloft, but I suspect some political advisers might prefer to aim for more efficient and less catastrophic infrastructure projects. []
  3. It could be bio-fuel or batteries, of course, so supply is not an unsurmountable long-term problem, but it will be expensive nonetheless. []

Fred Singer’s climate consensus denial

So I read with some bewilderment1 a recent article by Professor S. Fred Singer on climate change. It jumps around a bit but mostly tries to attack the idea of scientific consensus. Singer’s logic leads from platitudes like this:

Scientific veracity does not depend on fashionable thinking.

to risible conclusions like this:

In other words, the very notion of a scientific consensus is unscientific.

This makes less sense than the reader comments beneath climate-related news articles. Take any established theory from any other scientific discipline — General Relativity, the Standard Model of particle physics, Evolution, Germ Theory, Genetics, etc. ad infinitum. If you follow Singer’s logic, these are all “unscientific”, not just in spite of overwhelming scientific support, but actually because of it. Presumably something can only be “scientific” if a large number of scientists disagree with it. This takes denialism to a whole new level.

The fallacy underlying Singer’s thinking (assuming, for the hell of it, that he’s actually being honest) is that “consensus” is equivalent to groupthink. Singer hasn’t apparently grasped the idea of a conclusion being arrived at independently by many people. But that’s what you should generally expect to happen if (a) we live in a universe that obeys rules, and (b) those people apply sufficient rigour in their observations and analysis, as scientists are expected to do.

But why is consensus important? Because we rely on experts all the time. An “appeal to authority” is perfectly rational when there is a disparity in expertise, as between climate scientists and laypeople. It’s not the scientists who rely on scientific consensus. They rely on rigorous observation and analysis. But laypeople lack the time and expertise to do the same, and for them (us), the notion of a scientific consensus is immensely important as a way of assigning credibility to particular scientific ideas.

Singer’s article actually begins by denying that any consensus exists at all, which is contrary to a number of surveys, and (if you pay attention to those who write about this sort of thing) the absence of any significant pool of climate expertise on the sceptic side of the debate. Singer is aware of the 97% figure — the proportion of climate scientists who agree that climate change is real and human-cased. His response? First of all:

The degree of consensus also depends on the way the questions are phrased.  For example, we can get 100% consensus if the question is “Do you believe in climate change?”  We can get a near-100% consensus if the question is “Do you believe that humans have some effect on the climate?”  This latter question also would include also local effects, like urbanization, clearing of forests, agriculture, etc.

The word “some” (underlined by Singer) is the key to his whole argument — an issue of wording on the survey questionnaires. Here are three surveys (of actual real-world climate scientists or climate science papers) that have each independently reported a 97% consensus:

  • One by Doran and Zimmerman (2009) that I discussed three years ago, which asked scientists the question: “Do you think human activity is a significant contributing factor in changing mean global temperatures?” (my underlining).
  • One by Anderegg et al. (2010), which classified 1,372 climate researchers as either convinced or unconvinced of the IPCC’s position, which is of course that humans are making a significant contribution to global temperature increases.
  • Another by John Cook et al. (2013), who examined and categorised 11,944 climate-related abstracts. Abstracts that minimised the impact of humans, or claimed that humans contribute less than half of the total effect, were counted as a rejection of anthropogenic global warming (AGW). This is another term for human-cased climate change, of course, but one that makes explicit its global nature.

In order words, the bar is set a lot higher, and so the consensus a lot more meaningful, than Singer makes out. Those who believe that humans are having “some” effect on the climate, but only a local or minimal one, have not been counted in the consensus.

Singer himself brings up a fourth survey by Oreskes (2004), which also found a consensus view among published papers. Singer only mentions this in order to dishonestly imply that something scandalous happened:

…after being challenged, Oreskes discovered having overlooked some 11,000 abstracts — and published a discreet Correction in a later issue of Science.

The “discreet” correction is advertised in large capital letters across the top of the downloadable PDF. The correction says:

The keywords used [in searching for papers] were “global climate change,” not “climate change.”

Not quite the same thing as “overlooking 11,000 abstracts”, which is Singer’s preposterous interpretation2. And notice that even the correction itself, raised by Singer just to spread doubt, again undermines his own point — we’re talking about global climate change here, not local effects.

In the midst of this, Singer has the audacity to cite his own survey without furnishing us with the wording of his questions3, finding of course that support for human-caused climate change is much lower. He does, however, tell us that it was done in 1990 with less than 100 respondents. It was also apparently targeted at the American Meteorological Society, because:

I figured those must be the experts.

Just smell the rigour. Meteorologists are not the experts — climate scientists are. But even if we assume the survey was done rigorously, it’s still much smaller than all of the above-mentioned surveys, and 24 years out of date.

But Singer also confuses surveys of climate scientists with public opinion polls:

On the other hand, independent polls by newspapers, by Pew, Gallup, and other respected organizations, using much larger samples, have mirrored the results of my earlier AMS poll.  But what has been most interesting is the gradual decline over the years in public support for DAGW, as shown by these independent polls.

The public does hold a much more cynical view of human-caused climate change than climate scientists, but Singer’s comparison here is utterly absurd. “Respected organisations” these pollsters may be, but what they do has no bearing on the existence (or otherwise) of a scientific consensus. They’re surveying laypeople, whose understanding of scientific issues is more a function of media coverage and ideology than of observation and analysis. Does Singer not understand the difference?

His other notable example is the “Oregon Petition”, said to have been signed by 31,000 “scientists and engineers”, 9,000 with PhDs. It’s clear that the list of signatories to the petition includes a very broad swathe of qualifications, most of which have nothing to do with climate science, and the majority of which probably have no connection to the active pursuit of scientific research at all (since a PhD is a basic qualification for a researcher in academia, and since less than a third of signatories claimed to have PhDs). The petition’s website itself states that only 31 signatories have a “climatology” qualification, a mere 0.1% of the total. It doesn’t say these are even PhDs, so they almost certainly include non-scientists. After all, the petition failed to ask signatories what they actually do, or in fact anything about them at all other than their name and self-reported qualifications (making the list impossible to verify). Singer also doesn’t concern himself with the difference between a petition and a survey. The former gives us a big, but ultimately meaningless number. The latter, more usefully, gives us the proportion of respondents (experts, in our case) who hold a certain view.

Singer’s other argument against the existence of the consensus is that there’s a global peer-review conspiracy. He complains about the corruption of the process — as evidenced by a few anecdotal examples gleaned from the “climategate” collection of stolen emails, in which scientists and journal editors are seen to be exercising their professional judgement. The whole point of peer review, of course, is to act as a front-line filter against the least meritorious scientific papers. Of course someone, somewhere, is going to have been making recommendations and sending communications about the worth or worthlessness of certain papers. The fact that so few climate sceptics ever get past this first hurdle annoys them terribly, but it doesn’t mean that the peer-review process across the world’s entire climate science community has become mired in systemic corruption. It could simply mean that said climate sceptics are full of shit (and doubly so for then claiming persecution). Given the quality of Singer’s other arguments, it’s hard to give him the benefit of the doubt.

Singer also briefly wheels out the “no warming for 15 years” myth, and complains that the fact of it having been the warmest decade on record is irrelevant. He comes armed with this self-defeating analogy:

It may help here to think of prices on the stock market.  The Dow-Jones index has more or less been level for the last several weeks, fluctuating between 15,000 and 16,000, showing essentially a zero trend; but it is at its highest level since the D-J index was started in 1896.

Singer argues that the current level does not indicate the trend, which is technically, pedantically true, but we’re never just talking about the current level. By saying that the Dow-Jones — or the current temperature — is the highest it’s ever been, we’re relating it to past levels, which is what a trend is all about. Singer just doesn’t want to admit that there’s such a thing as a long term trend that overwhelms whatever short-term trend he might find interesting. In the course of arguing that the Dow-Jones hasn’t changed much in weeks, Singer is actually conceding that it has changed considerably over the longer term. So, of course, has the global temperature. And it’s the long term trend that matters.

That’s certainly the case for climate models, which Singer laughs off for their apparent inability to explain short-term natural variability. But short-term variability is basically irrelevant in determining the broad magnitude and impact of climate change. A model doesn’t get “falsified” for failing to produce a level of precision that it doesn’t need and was never designed to produce. Run the models against the past temperature record and they quite successfully predict the large-scale shape and magnitude of the rise that we’ve observed.

Singer ends with a plug for one of his own creations:

The wild claims of the IPCC are being offset by the more sober, fact-based publications of the NIPCC (Non-governmental International Panel on Climate Change).

This is sheer delusion from the man who set up the NIPCC, which appears to be a group of cranks angry at not being taken seriously. The IPCC already considers and incorporates into its reports the full range of scientific opinion on climate change. Far from being “wild”, its claims are often considered quite conservative. Singer’s claims are nothing but denialism.

  1. In the naïve sense of one who expects intellectual honesty. []
  2. Presumably someone did a search for “climate change” and noticed that the tally of results was 11,000 higher than that reported by Oreskes. You might think that the simple, accidental omission of one of the search terms would explain the disparity in results. But the climate sceptics, bastions of reason that they are, know that really Oreskes must have had all those extra papers at hand and dishonestly or incompetently misplaced them. Because that sounds better. []
  3. For instance, did Singer ask survey respondents whether they believe that humans will cause the world to end, and did he count each “no” response as a rejection of human-caused climate change? He doesn’t see fit to tell us, even after raising the issue of wording. []

Straw alarmism

So much is said in the political catastrophe surrounding climate change that I can’t quite imagine anyone keeping up with it. However, rbutr has informed me that one particular pseudo-anonymous article at something called the “Independent Journal Review” (or “IJReview”) could do with a closer look, and so I shall oblige.

The IJReview discusses James Lovelock’s recent about-face in which he describes his previous position on climate change as “alarmist” (a word that tends to be thrown around rather loosely — I’ll come back that later). The IJReview doesn’t cite the original source — an MSNBC phone interview with Lovelock — but rather several secondary authors. This indirection doesn’t alleviate the irony of the IJReview’s own political cartoon poking fun at MSNBC for selective editing and taking things out of context (which appeared alongside the article at the time of writing). Presumably, unreliable sources become reliable when you don’t cite them directly.

The level of snark in this article is on the silly side of normal, with “hardcore environmentalists” described as “money-grubbing” and “power-grabbing”, a connection based on some undiscovered logic by which, I suspect, I could also prove that 1 = 2. There’s also the condescending use of “confesses” and “admits” to describe anything said by a stereotyped individual that doesn’t conform to the stereotype.

First, a word about Lovelock’s Gaia Theory/Hypothesis, which (as I understand it) supposes that the Earth/biosphere behaves as a single composite organism. There is no supernatural or spiritual element to this. Gaia, though named after a Goddess, is not supposed to actually be one; it is merely a statement about large-scale self-organising phenomena. Nonetheless, a religious movement called Gaianism seems to have grown up around a silly misunderstanding1 of Gaia, and Lovelock himself seems to suffer casual ridicule for it. The title of this article describes him as the “Guru” of Gaia Theory, while James Delingpole has him pinned as the “High Priest” and “founder” of Gaianism itself.

Continuing in this vein, the IJReview article states:

James Lovelock, the veritable Pope of Gaia Theory, has taken global warmists to task for treating manmade climate change like a religion rather than valid science. Poignantly, [Lovelock] claims that for many the green religion is replacing the Christian religion.

The second sentence is accurate — Lovelock did say that — but he makes a similar claim about the religiosity of climate change deniers. It seems obvious, therefore, that Lovelock draws a distinction between people who broadly accept that climate change is real and people who approach it with religious fervour (those he terms “greens”, though obviously some will disagree with that).

That there is a “green religion” (or equally a denier religion) is not necessarily an unreasonable claim to make; all large political movements seem to have a quasi-religious element to them, and this probably tends to really annoy any independently-minded thinkers who come into contact with them. However, one cannot confuse the “green religion” with actual science or economic modelling conducted in actual research institutions, which convincingly (for the non-religious) points to the need to do something about carbon dioxide. It does not take an environmental activist to realise this, but like all religions2, the “green religion” incorporates some ideas that are actually sensible.

Now let’s look at Lovelock’s actual message, as quoted by MSNBC:

“The problem is we don’t know what the climate is doing. We thought we knew 20 years ago. That led to some alarmist books – mine included – because it looked clear-cut, but it hasn’t happened,” Lovelock said.

“The climate is doing its usual tricks. There’s nothing much really happening yet. We were supposed to be halfway toward a frying world now,” he said.

“The world has not warmed up very much since the millennium. Twelve years is a reasonable time… it (the temperature) has stayed almost constant, whereas it should have been rising — carbon dioxide is rising, no question about that,” he added.

I find this curiously dismissive3. The millennium has no particular significance for science, and what makes 12 years a “reasonable” time? We know for a fact that the temperature trend has been steeply upwards for decades. If you ignore enough data — say, by picking an arbitrarily-recent starting point — you can always prove that, well, you don’t have enough data. If there are inexplicable fluctuations, the take-home message for laypeople is not “everything we know is wrong”, but “fluctuations are noise, and we’ve already seen the signal”.

Moreover, Tamino reports on a paper by Grant Foster and Stefan Rahmstorf, published in December 2011 (months before Lovelock’s above remarks), which concludes that all five major global temperature datasets do show statistically significant warming since 2000, with no evidence that the rate of warming has slowed. The authors achieved this analysis by removing known sources of natural variation, which seems to put paid to the substance of Lovelock’s assertion that “we don’t know what the climate is doing”. I suspect the climate science community knows a lot more than Lovelock gives it credit for.

We also ought to ask this: what precisely is “half-way to a frying world” supposed to look like? What was it exactly that Lovelock expected to happen by 2012 that didn’t happen? Perhaps it was elucidated in his 2009 book The Vanishing Face of Gaia: A Final Warning — the volume he has now essentially disowned. It received a positive review by Tim Flannery at the time, who begins:

James Lovelock’s latest book, The Vanishing Face of Gaia: A Final Warning… has an important message. In a few years, or a few decades at most, abrupt changes in Earth’s climate will begin, which will end up killing almost all of us and cause the extinction of almost all life on Earth. The tropics and subtropics will be rendered uninhabitable by this shift, and the few survivors will cling to favoured regions such as Britain and New Zealand. Lovelock believes there is little we can do to avert our fate, for the causes of the climatic shift are now so entrenched that they are in all likelihood irreversible. In his view the best we can hope for is personal survival in a world of warring nations or, if we are particularly unfortunate, a world ruled by warlords.

It must be said that this is alarmist, and well out-of-step with the IPCC’s projections, as Flannery acknowledges. I certainly haven’t heard the IPCC make any such dramatic short-term predictions. The main concern was always for the long-term when a litany of positive feedbacks are predicted to accelerate the rate of temperature increase. Nothing spectacular was supposed to happen as early as 2012 (though there are certainly worrying signs in the form of, for instance, Arctic ice depletion, glacial melt, ice shelf collapse and extreme weather events that, put together, are highly improbable in a world without climate change).

I’ll put Lovelock himself aside for the moment, while the IJReview article does some value-adding to his remarks:

The major issue with climate change acolytes is that they rarely if ever quantify the effect of man’s activities on climate change. Well, let me help them: It is a little more than 0.28%, based on Department of Energy statistics and verifiable scientific data.

“Veritable scientific data” is rather too strong a turn of phrase. The linked webpage was written by one Monte Hieb, who performs a calculation based on a suspiciously low number for the human contribution to CO2 levels — 11.880 parts per million.

(A quick aside: the 11.880ppm figure is then used to calculate that the human CO2-only contribution is 3.207% of all greenhouse gases minus water vapour by volume. The actual purpose of that very specific percentage — quite aside from its utter fictitiousness — is unclear, but it seems to have formed a core factoid in the climate denialist arsenal.)

Hieb cites another webpage by one Tom V. Segalstad as his source for the 11.880 ppm figure. Segalstad doesn’t seem to give us that figure explicitly4, but does produce his own calculations. He argues that the observed ratio of carbon-13 to carbon-12 in the atmosphere puts an upper limit of about 4% on the proportion of CO2 in the atmosphere that resulted from burning fossil fuels.

But this is highly misleading, as explained here. CO2 molecules in the air are continually recycled. Those that originated from fossil fuels are mostly re-absorbed by the biosphere, but in doing so they displace naturally-produced CO2 molecules that are then left in the atmosphere (rather than being absorbed themselves), resulting in an overall increase in atmospheric CO2 concentration. Perhaps only 4% of atmospheric carbon dioxide originated from fossil fuels, but a much larger proportion is there indirectly as a result of fossil fuel burning. The ratio of carbon isotopes has no direct bearing on the human-caused change in overall CO2 concentration.

What we do know, according to the US EPA, is this:

Atmospheric CO2 concentrations have increased by almost 40% since pre-industrial times, from approximately 280 parts per million by volume (ppmv) in the 18th century to 390 ppmv in 2010. The current CO2 level is higher than it has been in at least 800,000 years.

If this improbable spike were due to natural processes, it’s a hell of a coincidence that it happened so quickly after the industrial revolution.

Now, in backing cautiously out of this particular rabbit hole, we also discover that Hieb is actually talking about the greenhouse effect, which isn’t the same thing as climate change at all.

The IJReview article follows this up with another link that tries to imply that CO2 cannot be a problem because it’s only a trace gas. That’s a straightforward non-sequitur; it simply doesn’t follow. (To assuage intuitive doubts, consider that cyanide is lethal at the concentrations we’re talking about for CO2.) The linked article also trumpets the logarithmic effect of CO2 on temperature, which is a great insight to throw at the climate modelling community who know that perfectly well and who must routinely deal with things a lot more complex than log functions (with apologies to the less mathematically-inclined).

We’ll return to CO2 concentration shortly. For now, we’ll instead confront this concoction of denialist memes:

Fellow enviroscientist Phil Jones, he of Climategate fame, admitted that there had been no global warming since 1995 in February 2010. Lovelock seems to refer to Phil Jones of the infamous “hockey stick” graph  when he declares that it is a “sin against science” to fudge data.

Climategate” has become a mythological scandal, along with the “infamous hockey stick”, that must be mentioned at all opportunities. Lovelock and others have rushed to judgement on the basis of selected stolen private emails — inherently flaky evidence. More than two years later, no allegation of “fudging data” has been sustained that I’m aware of. One wonders what Lovelock or the denialists actually want to happen over the matter, after the various investigations found no actual wrongdoing5. Do they simply want more investigations? Or should we just ignore the real findings and pretend that everyone was guilty of all the things we feverishly imagined about them?

That aside, Phil Jones emphatically did not “admit” there had been no warming since 1995, and he would have been lying if he had. Jones actually said:

I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level.

This was poorly summarised as “no statistically significant warming”, which of course morphed into “no warming”. Statistical significance is nothing but a arbitrarily-chosen threshold level of probability; its absence does not alter the fact that Jones did observe a 0.12 degree/decade temperature increase. The issue is rendered irrelevant by the findings of Foster and Rahmstorf (and probably others), as mentioned above.

The IJReview article also has a swing at the “hyperbole” of James Hansen’s warning over the mining of Canada’s tar sands, where Hansen says:

Canada’s tar sands, deposits of sand saturated with bitumen, contain twice the amount of carbon dioxide emitted by global oil use in our entire history. If we were to fully exploit this new oil source, and continue to burn our conventional oil, gas and coal supplies, concentrations of carbon dioxide in the atmosphere eventually would reach levels higher than in the Pliocene era, more than 2.5 million years ago, when sea level was at least 50 feet higher than it is now. That level of heat-trapping gases would assure that the disintegration of the ice sheets would accelerate out of control. Sea levels would rise and destroy coastal cities. Global temperatures would become intolerable. Twenty to 50 percent of the planet’s species would be driven to extinction. Civilization would be at risk.

It’s worth contrasting this against Lovelock’s retracted predictions of global doom. The trouble is that Hansen actually knows his climate science, so you can’t dismiss him quite as easily as Lovelock. His idea here seems relatively straightforward: there’s enough carbon in those tar sands to wreak havoc. The world has been operating for some time on the basis that 450ppm was the “safe limit” for CO2 concentration. Hansen generously allows 500ppm in his article, but others have suggested that 350ppm is closer to the mark (which is a problem, because we’re already at 396ppm and rising). Hansen is simply comparing the projected future CO2 concentration to the reconstructed past. In effect, he’s citing precedent. This isn’t alarmism — it’s a reality check.

The IJReview article then makes a final digression into fracking, at which point my interest in the matter is finally exhausted. Lovelock seems to like the idea of fracking as well, but at the moment I don’t know enough to comment.

Although it’s an interesting exercise to write these articles, it’s unfortunate that there’s so much material. The IJReview article is a good example of a game of Chinese whispers played between people who already know what they want to hear.

  1. I suspect there is some overlap with the people who also try to coerce Quantum Theory into some sort of new-age religion. []
  2. Scientology is probably excepted here. []
  3. Indeed, a lot of what Lovelock has been quoted on recently appears to boil down purely to flippant cynicism: collectively we’re idiots, everyone is also an idiot individually, and nothing will help. Cynicism of that magnitude irritates me because it’s intellectually lazy, fundamentally useless and diverts attention from attempts to solve (or even understand) the problems we face. []
  4. I can only speculate that 11.880ppm was a product of some unseen conversation or calculation. []
  5. The investigations did find that Freedom of Information requests had been mishandled, but this has nothing to do with science per se. []

Hopes for 2012

Here’s a bit of everything for the new year — some hopes for what we could and should be doing as a nation, in no particular order.

We must address the asylum seeker debate with decency, maturity and humility. We should accept many more refugees, and at the same time encourage other countries to do so too. There’s really very little downside to this, save for the political ramifications of xenophobia. The world collectively might not be interested in finding a safe home for all its refugees, and so if we let refugees come to us, they will certainly continue to do so. We might prefer that their lives were not further jeopardised by the journey, but, having arrived, it’s an utter perversion of human decency for us to turn them away, no matter how much we’d like to discourage further risky voyages. We must not create disincentives that rely on penalising innocent people; we have no right to play chess with human beings.

We must get some perspective on the economy; it is not a blanket reason for putting aside all other problems. Yes, it’s important. No, we are not teetering on the edge of starvation. Panic is precisely the thing that causes economic problems in the first place. Basically, let the disinterested economic experts make rational, progressive decisions based on careful, objective modelling, and ensure there is a safety net for the poor. Everyone else, suck it up.

We must continue to insist that our politicians get off their conservative arses and legalise same-sex marriage. This is truly a no-brainer. The arguments against it are utterly, unequivocally spurious, and will dissipate like so much hot air once the requisite legislation is passed. Nobody opposes same-sex marrige for any substantive reason, but basically just “because”. Once legalised, the whole “debate” will be relegated to the inane murmurings of ineffectual dinosaurs. (Do politicians fear a backlash from voters angry that their marriages are suddenly devoid of meaning following the gender requirements being dropped?)

For the love of humanity can we please redouble efforts to improve the health and living standards of those living in remote Aboriginal communities? Of course it won’t be done in a year. It’s not just about grand rhetorical gestures — though these have their place — and it’s certainly not about sending in the army. We have a lot of smart, dedicated people who have been on the case for some time, and surely by now we’ve learnt a thing or two about what can usefully be done, given sufficient government funding.

The climate change debate is not over, and won’t be for decades. We must not lose sight of the fact that the goal, in the end, is zero (or even negative) carbon emissions. The purpose of a carbon price is not simply to reduce emissions, but ultimately to price them out of existence. To make this work, alternatives must exist. Australia should, by all rights, be a world-leader in solar energy. We could be a world-leader in all kinds of renewable energy. Surely there is much more scope for public and private funding of renewable energy research. We might only contribute 1.5% of the world’s greenhouse gas emissions, but renewable energy research could help reduce everyone’s emissions, not just our own.

Recycled drinking water — get used to the idea, people. Water efficiency is vastly more important than your squeamishness; there’s really no rational objection. Even now, the water you drink has already passed through the digestive tracts of a trillion different organisms, without any technological assistance. Water recycling is the lowest-hanging fruit for securing our water supplies (especially in places like Perth that are drying out). Why would we ignore it in favour of energy-intensive desalination  or enormous engineering works to transport water from thousands of kilometres away? Yes, we can build wind farms, tidal generators, etc. to power desalination plants, but we could be using that power to replace coal, not just to replace water.

The location of the Square Kilometre Array (SKA) — the world’s largest telescope, and one of the world’s largest scientific projects — will be decided in 2012: either Australia or South Africa. Let’s step back from the parochial contest. Australia might not get it, but would this be such a terrible outcome, all things considered? Maybe Africa would benefit more from this project than Australia. Besides the raw economics, the presence of such visible, cutting edge science must have some inspirational effect. Scientists can travel, but for young Africans trying to discern their opportunities in life, a local SKA would surely leave an impression.1

Finally, in an Olympic year, let’s not lose sight of our non-sporting heroes. A nation defined by sport is a nation not defined by its doctors, lawyers, scientists, engineers and other professionals. Sport is exciting, and important in its own way, but not really on the same scale as curing illness, defending human rights, exploring the universe and creating things that have never existed before.

Now, you lot, get started on that while I take a holiday.

  1. The same would be true of young Australians, but we are relatively spoiled for choice. []

The Galileo gambit movement

I’ve had another sudden fit of pseudo-artistic buffoonery.

I stumbled across the Galileo Movement largely by way of Wendy Carlisle’s Background Briefing report:

In February this year a new group emerged: the Galileo movement. Its scientific advisers are the who’s who of the international climate sceptics movement. Its patron is the powerful Sydney radio personality Alan Jones. The Galileo movement is aiming to kill the carbon tax, and it’s aiming to do this through attacking the science of climate change.

This is a fabulously un-self-aware group of climate change denialists who liken their cause to that of Galileo, and who purport to offer the Real Truth of the Earth’s climate. They are the living epitome of the Galileo gambit, which itself is much older and is described by RationalWiki as follows:

They made fun of Galileo, and he was right.
They make fun of me, therefore I am right.

I feel the following diagram adequately summarises the situation:

Creative Commons License
Galileo Gambit Venn Diagram by David Cooper is licensed under a Creative Commons Attribution 4.0 International License.

This is all very Australia-centric, of course, and wholly political, though they claim otherwise. The stated purpose of the Galileo Movement is merely to stop Australia’s carbon tax – an entirely political goal – not to actually redress the horrific corruption of science they claim to be occurring. The “corruption of science” seems more like an excuse for their own political predicament than an actual problem that must be solved. If such systemic corruption of the scientific process was real, after all, it would be far worse a problem than any mere tax1. However, the movement’s scientific literacy is clearly razor-thin, with adorable statements like this:

We care about freedom, security, the environment, humanity and our future.

The Galileo Movement’s co-founders are retirees Case Smit and John Smeed. Their business backgrounds are in science and engineering – science’s real-world application. Their experience is in environmental protection and ensuring air quality.

At first they simply accepted politicians’ claims of global warming blamed on human production of carbon dioxide (CO2). When things didn’t add up, they each separately investigated. Stunned, they discovered what many people are now discovering: climate claims by some scientists and politicians contradict observed facts.

Here’s another theory: Case Smit and John Smeed have never been involved in actual climate-related research at all, but through some intrepid Googling discovered that People On The Internet were having arguments. A stunning revelation indeed. Not having any particular notion of what real science is actually supposed to look like, they simply believed those people who appeared to be more outraged. Just as in Galileo’s time.

  1. Denialists rarely realise the scale of the allegations they so casually make; if they did, they would have to confront their implausibility. []

Poor persecuted Monckton

His Great and Wondrous Beneficence the Lord Christopher Monckton did, after all, give a lecture at Notre Dame University. Attempts (initiated by Natalie Latter) to dissuade Notre Dame from lending Monckton its credibility did not come to fruition, though drawing attention to his Lordship’s rank lunacy is always a small victory in itself.

As the letter puts it:

We all support academic freedom and the freedom to express our ideas and beliefs. However, Notre Dame University has a responsibility to avoid promoting discredited views on an issue of public risk. Notre Dame’s invitation to Lord Monckton makes a mockery of academic standards and the pursuit of evidence-based knowledge.

This has been laughably characterised as an attempt to “gag” Monckton (who has a minor obsession with characterising people as fascists and war criminals, suggesting for instance that climate scientists ought to stand trial for genocide). Does anyone honestly think that Monckton actually could have been gagged?

This call to preserve academic standards morphed (perhaps predictably) into a spurious fight for free speech. Tell me, dear reader: when was the last time you exercised your apparently fundamental democratic right to give a public lecture at a university?1 Do you believe that you have that right; that a university has a duty to invite you to give a lecture if you see fit to give one? Why should Monckton be afforded this privilege, when clearly “ordinary” members of the public are not?

Some, such as Professor Chris Doepel at Notre Dame, argue that all points of view must be heard. This is the refrain we hear from creationists asking that “Intelligent Design” be taught in schools. It’s a convenient rhetorical tool for engineering doubt. The consensus of virtually all the relevant experts, arrived at by considering the entire gamut of objective data collection and analysis conducted over decades, is made to look like only one set of opinions, rivaled by another set of opinions formed simply by making things up. Doepel makes the following self-refuting remark:

The university does not take a view one way or the other on the positions advocated by Christopher Monckton.

But that is a position on Monckton. An individual person might legitimately claim not to know enough to form an opinion2, but it beggars belief that a university – a place wherein truth is uncovered and disseminated – would have formed no position on one of the most outspoken and controversial figures of our time. A refusal to condemn Monckton’s views, for an institution that cannot possibly claim ignorance of what he stands for, is effectively an endorsement of those views. We certainly know where Notre Dame stands on legitimate climate research and climate action, then.

Others (such as the Fremantle Mayor Brad Pettitt) believe we should just let Monckton speak, and take the time to refute his claims. But this is to accept the false dichotomy that either he be allowed to speak wherever he likes, at any institution, or we tie him up in the basement. Monckton was clearly never in any danger of actually being silenced, not even if Notre Dame had heeded the call to preserve its academic integrity. Universities have credibility in the first place precisely because they discriminate between views supported by evidence and views not so supported (the same as scientific journals, and the scientific process in general). One can delude oneself into thinking that this is somehow undemocratic, but then reality isn’t democratic. At some point, for the sake of advancing the human cause, we must stand up and pass judgement; not on each other, but on our ideas. Science, technology, economics, etc. are not served simply by sitting and listening politely and “fairly” to endless regurgitations of refuted arguments. We have the media and the Internet for that; universities should know better.

Some believe we should just ignore Monckton. However, the man is steering the public debate in ways that are fundamentally detrimental to the prospects for sensible policy making. We cannot just ignore him. Academic institutional credibility aside, he already has all the media coverage anyone could dream of. This isn’t the result of some PR folly by his critics, but rather his oratory skills and the cozy hardline ideological relationship he has with some very loud and obnoxious media personalities.

It is incumbent upon academics to preserve the integrity of their institutions, and to confront misinformation that threatens to derail rational decision making. Free speech is a right, no doubt, but credibility must be earned.

  1. It is entirely possible, I suppose, that you have indeed given a public lecture at a university, but I think you’ll agree that it’s not exactly a right. []
  2. I sometimes admire those willing to admit ignorance rather than pick whichever view “feels” better. []

Who is Dennis Ambler?

Continuing on (a bit) from my last post, I’m going to examine another of Dennis Ambler’s articles for the Science and Public Policy Institute (SPPI). This one is mostly a long rambling swipe at lots of different and very accomplished individuals, and not (as in the other case) an outright attempt to reinvent the laws of mathematics and statistics.

Here, Ambler focuses on a report written for the American National Academies, called Advancing the Science of Climate Change. He is apparently responding to an article in the Washington Post by Sherwood Boehlert, who quotes a key line from the report’s summary:

A strong, credible body of scientific evidence shows that climate change is occurring, is caused largely by human activities, and poses significant risks for a broad range of human and natural systems.

This is the official, considered position of the American National Academies, and closely resembles a Q&A document released by the Australian Academy of Science:

The Earth’s climate has changed. The global average surface temperature has increased over the last century and many other associated changes have been observed. The available evidence implies that greenhouse gas emissions from human activities are the main cause. It is expected that, if greenhouse gas emissions continue at business-as-usual rates, global temperatures will further increase significantly over the coming century and beyond.

Ambler doesn’t (here, at least) address the Australian statement, or any of the other statements issued by other national science academies and other scientific organisations around the world. We’ll set that aside for now.

His point appears to be that the Panel on Advancing the Science of Climate Change (presumably responsible for the first quote) is stacked with advocates* of anthropogenic global warming (AGW). He goes into great detail about the nefarious activities of various board members, such as being IPCC authors, members of NGOs, members of advisory boards, having links to the United Nations and being either corporate- or government-funded. Scandalous, I know.

However, Ambler’s entire argument rests on the notion that the aforementioned organisations have already somehow been discredited. That may be true in his head, because the IPCC says all the things he doesn’t like to hear. However, there is no objective reason to think that the IPCC is not essentially fulfilling its intended function: the careful, objective assessment of the science behind climate change and its implications. His argument also relies on the assumption from the outset that the AGW consensus does not exist. If consensus is real, then it’s hard to imagine what could be wrong with having such a panel “stacked” with those who’ve poured their energies into addressing the problem.

Ambler’s other complaint is one I’ve heard repeated for other advocates of climate action – that they’re not climate scientists:

I doubt a dissenting voice on “the science” is ever heard in their deliberations. As can be seen, climate scientists are very much in the minority. It seems that a mix of economists, social scientists, engineers, NGO’s and corporations in receipt of government funding, form the main strength of these particular committees.

I doubt a dissenting voice on “the science” would ever be heard no matter how many climate scientists you added (Ambler has tried to argue against the existence of the consensus, but not too successfully.) Nevertheless, at first glance, it might seem common sense that climate change panels ought to be populated entirely by climate scientists, until you realise that climate science only identifies the existence of the problem. Climate science says nothing about the humanitarian, economic, or even environmental effects of climate change, and it certainly does not say what we might do, as a society, to prevent or mitigate them. This is not a problem with climate science – it simply reflects the cross-disciplinary nature of climate change.

Climate change denialism does not appear to recognise the distinction between all these facets. It does not accept, for instance, that someone can be qualified to talk about reducing CO2 emissions unless they can also convincingly explain the data used to establish the effects of CO2 in the first place. To an armchair “sceptic”, these two discussions belong in the same discipline. Except they don’t. There is a very good reason why the Stern and Garnaut Reviews, for instance, were written by economists rather than climate scientists. Modeling economic costs just isn’t part of climate science; the issue transcends disciplines.

In setting out to undermine all work on climate change**, climate denialists become Jacks of all trades and masters of none. They perceive the entire concept of climate change as being the domain of a single discipline (climate science), because they don’t realise the depth of analysis that underlies each part of that picture. Analysing the effects of greenhouse gases on temperature could be a life’s work, for instance. Analysing the effects of temperature increases on agricultural practices is another life’s work, as is modelling the economic costs and benefits of reducing CO2 emissions, and so on. The true experts each spend their time on a relatively small part of the problem, but paying enormous attention to detail. They rely on other experts to fill in the gaps where needed, because no single person can be an expert in everything. Meanwhile, denialists skip lazily across the entire scope of the problem and engage only in shallow commentary and nitpicking. It would be difficult to comprehend just how many different disciplines are crossed when you naïvely believe that you (and/or those you follow) possess the entire range of necessary expertise.

Thus, the many genuine scientific, humanitarian, political and economic debates regarding climate change are, in denialist circles, mashed crudely into just one big issue, adjudicated solely by climate scientists (except for all the ones who write those terrible papers about hockey stick graphs; they don’t count).

Just for fun, let’s examine the scientific credentials of some SPPI contributors, starting with Dennis Ambler himself. Ambler puts his name to 14 of the last 100 articles (at the time of writing), and thus appears to be the most prolific recent contributor to the SPPI collection. However, try as I might, I cannot find any biographical information on the man at all. Even SPPI’s own Personnel page neglects to mention him. There are no details of his history, qualifications, accomplishments, collaborations, involvements with other organisations, or even interests. “Dennis Ambler” might as well be a pseudonym for all I can tell.***

Next in line is Christopher Monckton, named as the author of 10 of the last 100 articles. Fortunately he is mentioned in the Personnel page, as being an expert on virtually everything, despite not possessing any qualifications at all on anything remotely resembling science or economics. It’s worth a read.

Then there’s Ross McKitrick, with 4 out of 100 articles. He’s an economist, which I hope doesn’t put him offside with Ambler.

The remaining articles were contributed by a slew of authors with (I presume) only a tangential relationship to SPPI itself. I won’t discuss them, except to note that the current President of the Czech Republic Václav Klaus is among them. Doubtless he too specialises in climate science. It’s all about expertise, you understand.

* It’s hard to maintain the correct wording here, since it can be a little unwieldy. Nobody advocates climate change – that’s precisely what we don’t advocate.

** Climate denialism, in aggregate form, opposes every facet of the science on climate change – virtually every finding of every paper – which would be quite a remarkable occurrence if we held it to be intellectually honest. Individuals may accept certain parts of the science to varying extents, and often claim that “nobody” seriously disputes those parts (e.g. that the Earth is currently warming), but in reality every single detail is disputed in some corner or other. (The only exceptions to this are the occasional papers written by denialist champions like Steve McIntyre.)

*** To be fair, it would be hypocritical of me to suggest that all this information is a pre-requisite for making public comments. However, I’m just a pseudo-anonymous blogger, while Dennis Ambler is backed by an “Institute”, conferring a facade of expert credibility.

Consensus Bashing

The Science and Public Policy Institute certainly does provide a lot of hilariously twisted commentary on climate change.

Two years ago (January 2009), Doran and Zimmerman (D&Z) published a paper based on Zimmerman’s masters thesis. Unsurprisingly, they found that the vast majority (97%) of climate scientists think climate change is real and human-induced. This kind of thing really, really irritates climate change denialists, and so we have Dennis Ambler from SPPI launching into a blisteringly woeful attack on the survey.

He sets the tone with this:

[The survey] was roundly de-bunked at the time by several commentators and it would have been forgotten and consigned to its proper place in the dustbin, if it hadn’t been continually
quoted by activists as fact.

If you’re going to claim that a paper has been “roundly debunked”, a little elaboration would not go astray. Some of us might just be curious about just what arguments were put forth, and you’re not giving us much to go on. Also, if we’re going to lend it such credence, I would expect some sort of expertise to be involved in this debunking, not just a vague reference to unspecified “commentators”.

He then bemoans the surveying of experts as a means of assessing scientific opinion:

This is not arcane knowledge for the select priesthood, this is science and we can read scientific papers and apply quality judgements to them, whether we be specialists or not.

No, Ambler, you really can’t. I know this for two reasons:

  1. Those who’ve genuinely tried to read and understand technical papers in a field they don’t work in will know just how much of an uphill battle it can be. There’s unfamiliar jargon, horrendous equations, often enormous amounts of assumed background knowledge, and frequently little attention paid to overall readability. These papers are written for a very narrow audience, and you can’t just plant the flag of egalitarianism and ignore all the hard work that goes into building the necessary expertise.
  2. Even if you were equipped to read and understand technical papers from any discipline, the sheer quantity of them would make the task logistically impossible. They don’t just dribble out one or two at a time every news cycle. There’s countless thousands (possibly millions) of them, and nobody (scientists included) can ever hope to read them all. That’s why we have surveys. Even researchers themselves rely on survey papers, for instance, to make sense of their own fields.

The remainder of Ambler’s article demonstrates his unique inability to “read scientific papers and apply quality judgments”. I say “unique” because D&Z’s paper is actually quite short and accessible. Given a modicum of education and common sense, there really isn’t much of an excuse for not understanding it.

We are also told that only 5% of the original sample responses were climate scientists, so if we pragmatically apply those proportions we end up with just 141 from the US, 9 from Canada and just 6 from 21 countries around the world, hardly a global consensus.

Is there some significance to the 5% figure? The survey was a broad look at the opinions of Earth scientists. Climate scientists just form an important subset of that population, and it’s hardly the fault of the authors or anyone else if the proportion happens to be 5%.

Moreover, Ambler knows he can estimate the number of respondents from each country, but he seems not to understand that the very same mathematical device is the reason you don’t need to ask everyone in the world. So long as you have a representative sample (and consulting a database of Earth scientists, as D&Z did, would seem to be perfectly acceptable), you can generalise your findings. If 97% of your sample believes X, and your sample is representative of a given group (e.g. climate scientists), then you infer that about  97% of the overall group believes X as well. This is the entire basis of surveys. If this statistical logic did not hold, surveys would not exist.

Why so few non-American climate scientists? That’s just a result of the database used by D&Z, coming as it did from the American Geological Institute. There’s no reason to think that American and non-American climate scientists are likely to have any specific, major points of professional disagreement, so this shouldn’t be a problem.

We find that they originally contacted 10,257 scientists, of whom 3,146 responded, less than a 31% response rate. “Impending Planetary Doom” was obviously not uppermost in the minds of over two thirds of their target population.

31% is a very good response rate, in my experience. I would not have raised an eyebrow if it was only 10% (except that the authors would then have been less well-equipped to draw conclusions). It’s silly to start attributing reasons for non-response, because by definition you don’t have the data. It’s certainly very silly to suggest that 7111 scientists don’t care about the issue merely because they failed to fill out a questionnaire on it. Perhaps they were too busy actually working on the problem!

Ambler does us a service by linking to D&Z’s summary paper, but he’s a bit of a cheapskate:

The paper is behind a pay wall but there is a comprehensive summary here.

It’s obvious from reading Ambler’s article that his own investigative skills cannot penetrate this “pay wall”. Despite describing the summary as “comprehensive”, he repeatedly complains about missing details. For example:

There is little detail of how many peer reviewed papers are needed to qualify as a specialist, it could by their definition be just two papers, one of which needs to be on climate change. What a poor example of scientific enquiry this survey really is.

The one-and-a-bit-page summary paper does not, of course, include all the information from the 141-page thesis. The price for an electronic copy of Zimmerman’s thesis is only $US 2, hardly a prohibitive sum. I bought a copy myself just so that I could write this post. Zimmerman provides an extensive explanation of the process of verifying whether survey respondents are, in fact, active publishers on climate science (page 16). However, this kind of nit-picking was never going to undo the rather stark results.

There were supposed to have been nine questions asked, but we are only given sight of two of them.

Again, this is what you get if you only read a summary. For those interested, the full set of nine questions consisted of four opinion-related questions and five demographic questions:
  1. When compared with pre-1800’s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?
  2. Do you think human activity is a significant contributing factor in changing mean global temperatures?
  3. What do you consider to be the most compelling argument that supports your previous answer?
  4. Please estimate the percentage of your fellow geoscientists who think human activity is a contributing factor to global climate change.
  5. Which percentage of your papers published in peer-reviewed journals in the last 5 years have been on the subject of climate change?
  6. Age
  7. Gender
  8. What is the highest level of education you have attained?
  9. Which category best describes your area of expertise?

Ambler of course takes issue with the first two questions. For question 1:

Has it got warmer since pre-1800 levels? This really depends on the time period referred to. Do they mean the Little Ice Age, when disastrously cold temperatures caused massive loss of life and untold hardship? Of course temperatures are now warmer than that desperate period in climate history. Is that what they would wish to regard as normal?

Climate denialists often have a mild obsession with two proposed fluctuations in global temperature over the last few hundred years. They explain away the current warming trend by saying that we’re merely coming out of a cold period (the Little Ice Age), and that temperatures have been warmer in the past (the Medieval Warm Period), but the evidence for either of these is rather limited. This is related to another pet denialist obsession: the “hockey stick” graph, which shows that the current warm temperatures are unprecedented over at least the last millennium. It is essential denialist lore that the hockey stick has been discredited. In reality, it has numerous independent replications.

For question 2, on whether human activity is a factor:

This is the classic closed question, in that it implies mean global temperatures are being changed and someone must be responsible.

First, respondents are not asked this question if they previously said that temperatures remained relatively constant; so no, the question does not assume temperatures are being changed. It certainly does not assume that “someone must be responsible” – I have no idea how Ambler could have read that into it.

About half-way through his article, Ambler makes his biggest departure from reality, and one that cannot be excused by lack of information. This divergence begins as follows:

Of [the 3146 respondents], only 5% described themselves as climate scientists, numbering 157. The authors reduce that by half by only counting those who they classed as “specialists”.

The authors do no such thing. They categorise their 3146 respondents by field (climatology, geology, etc.) and whether more than 50% of their recent published papers were related to climate science. In the media, the most widely-reported statistics are, appropriately enough, for actively-publishing climatologists. However, this categorisation does not omit anyone, but merely provides more detailed information.

It is disingenuous to now use the “climate scientists” as a new population sample size. The response figure of 3,146 is the figure against which the 75 out of 77 should be compared and in this case we get not 97% but just 2.38%.

Ambler appears not to notice that there are statistics on the complete set of 3146 respondents, not just the 77 who happen to be actively-publishing climate scientists. Ambler’s 2.38% is the proportion of respondents who agree that humanity has an influence on climate and who also happen to be climate specialists. If you think that climate change is real but you’re not a specialist, Ambler is counting you in the total population but not in the “yes” pile (and so by implication in the “no” pile).

That’s dishonesty if ever I’ve seen it. D&Z expressly state in their summary paper that 90% of respondents overall agreed that temperatures have risen, and 82% agreed that humanity was a factor. Ambler expressly ignores these statistics and then tries to reverse engineer them using profoundly broken mathematics.

The original number contacted was 10,157 [sic] and of those, 69% decided they didn’t want any part of it, but they were the original target population. When the figure of 75 believers is set against that number, we get a mere 0.73% of the scientists they contacted who agreed with their loaded questions.

Ambler now wants to count non-respondents in the total as well, making the unsupportable implication that they would have said “no”. This is utter nonsense and is a complete corruption of general survey methodology. You use the data you have – that’s how science works – not by making assumptions about the data you don’t have.

Ambler ends by ridiculing media reports that quite fairly echo D&Z’s findings. Apparently they’re not privy to his powers of deduction, and neither am I.