July 2nd, 2006
I am a rationalist; I believe that we must rely upon reason to address the problems we face. In doing so, we must be careful not to permit our prejudices to distort our reasoning processes. In the matter of global warming, I am appalled by the gross distortions of logic and abuses of reason perpetrated by those who deny the existence of the problem and oppose measures to address it. This essay offers a catalogue of the crimes against reason committed by this school.
“The science is unproven”
This argument assumes that scientific theories are provable; the assumption belies a complete misunderstanding of science. No scientific theory ever has been or ever will be proven, for proof is a concept from logic and mathematics and is confined to that ethereal realm.
Consider, for example, Newton’s Second Law, one of the most elementary concepts from physics. Surely this law (expressed in mathematical form as F=ma) is the most solidly established concept in the entire realm of science. It underlies all of modern dynamics; were the Star Trek character “Q” to suddenly invalidate it, we would have no choice but to throw away the entirety of physics and start all over.
Newton’s Second Law has been confirmed in thousands – nay, millions – of tests. From the operation of automobiles to hydraulics, power plants, aircraft, and space travel, Newton’s Second Law has yielded perfect results.
But these millions of confirmations do not constitute proof of the Second Law. Proof requires that we demonstrate that, in every single application of the Law, it yields correct results. We have not done so. We have not measured the motions of unseen planets orbiting unseen stars in distant galaxies and shown them to obey Newton’s Second Law. We have not tracked the trajectory of every falling leaf, every buzzing bee, every splashing drop of water and shown them to obey Newton’s Second Law. We have instead taken a very large statistical sample of dynamical behavior and demonstrated that all these phenomena obey Newton’s Second Law. That does not constitute proof – merely statistical likelihood.
If even Newton’s Second Law cannot be proven, then surely no other scientific theory is provable, and such is the case with global warming. Even if, a century from now, we find ourselves roasting to death in a sun-blasted desert that once was Alaska, we would not be able to assert that the theory of global warming had been proven. The concept of proof is beyond the reach of science.
I shall now indulge in a digression on a fine point. Often scientists will prove mathematical theorems associated with scientific theories. For example, consider Kepler’s Laws. These laws actually preceded Newton’s Laws, but were nothing more than mathematical relationships that Kepler had induced from Tycho Brahe’s observations. Kepler offered no explanation of why these laws might be correct. Newton, however, was able to mathematically prove Kepler’s Laws by assuming his own Laws. In other words, he proved that, if Newton’s Laws were correct, then Kepler’s Laws must also be correct. This “proof” of Kepler’s Laws was not absolute proof – merely proof of conformity with other laws. All mathematical proofs of scientific laws are similarly limited.
Thus, rejecting global warming because it is unproven lacks logical merit. We simply do not attempt to prove any theory in the first place; instead, we attempt to demonstrate its credibility. This requires scientific judgement: the careful assessment of all the arguments, pro and con, leading to an overall (and necessarily tentative) conclusion as to the likelihood of the theory’s correctness. Every citizen is welcome to apply their own judgement to the issue, but of course the most reliable judgements will come from those who are most familiar with the issues: the scientists themselves. Which brings us to my second item.
“We can’t trust the scientists.”
I find this argument particularly obnoxious. Its perpetrators, confronted with indisputable evidence that the great majority of scientists adjudge global warming to be a very real and very serious issue, reject the scientists as unreliable judges in matters of science. They argue that scientists are all evil liberals, or that they have financial incentives to lie, or that scientists have been wrong before. Let us consider each of these accusations.
“Scientists are politically prejudiced liberals”
I am wickedly tempted to offer the argument that this claim is unproven; certainly the evidence in its support is far, far weaker than the evidence in favor of global warming. However, I need not rely on such debating tricks, as I have stronger arguments at hand that do not rely on irony.
The heart of the issue concerns the motivations of scientists; would they permit their political opinions to affect their scientific judgement?
We must all agree that scientists are human and are no less subject to the foibles of humanity than anybody else. But the argument cuts both ways: scientists, being human, are as varied and heterogeneous as the rest of us – which argues against the notion that scientists are some homogeneous conspiracy of like-minded liberals. There are tall scientists and short scientists, rich scientists and poor scientists, nasty scientists and nice scientists – and yes, there are liberal scientists and conservative scientists. It could well be that there are more liberal scientists than conservatives scientists; I don’t know. But let’s dispense with conspiratorial notions right now; there are too many scientists to pull off such a nefarious conspiracy.
A more promising approach is to examine science as a social system, an institution with its own mores and methods. Few people outside of science understand how “the system” works, which explains why these preposterous claims of liberal scientific conspiracies get any traction in the first place.
Some people measure their success in life by their accumulation of wealth. They devote their lives to the pursuit of wealth. There are many such people in our society; scientists are not among them. Any scientist who’d rather be rich can get a lot more money in industry than in academia. And there are many such people. But they aren’t the kind of scientists we refer to when we ask whether we can trust scientists. We’re concerned with the academic species of scientist. These people measure success by the esteem of their colleagues, measured by the number of scientific papers they publish and the respect those papers garner. They devote their lives to the goal of publishing papers that impress other scientists. That’s what they want.
To achieve success in science, a scientist must develop ideas that are a) novel, b) significant, and c) correct. If the idea is obvious or derivative, nobody pays attention. If it is insignificant, nobody pays attention. And if it’s wrong, other scientists will shoot it down in flames. One of the beauties of “the system” of science is the symmetry of the system. You can make a name for yourself by publishing a significant and novel idea. You can also make a name for yourself by shooting down an idea somebody else has published. This creates an incentive to attack other people’s ideas – and you can be certain that such attacks take place. Few people appreciate the ferocity with which scientists attack each other. As academics, they maintain a veneer of decorum, but the feelings run deep and often burst out into the open. If you think that business is war, and that some corporations are snakepits, you ain’t seen nothin’. Attend a scientific conference or dig into the politics of an academic department. You want to know the real reason why academics wear those long robes at graduation ceremonies? It’s to conceal the knives.
To anybody familiar with the way the world of science works, the notion that scientists have joined together in some vast conspiracy to fool the world is not just preposterous – it’s patently preposterous. Scientists can’t agree on anything. Even obviously correct ideas such as Einstein’s special relativity take years to attain general agreement. The bickering never stops. These people make Congress look decisive.
“Scientists have financial incentives to lie”
This argument is so absurd that it deserves little attention. Who, I ask, is paying scientists to lie? The Sierra Club?
A variation on this theme is the suggestion that scientists have to toe the party line to get ahead in the world of science. As I explained above, this is precisely the opposite of the truth. If all you do is parrot the general consensus, then nobody pays attention to you. It’s the troublemakers, the people who rock the boat and upset existing theories who become the eminent scientists of the world.
“Scientists have been wrong before”
I once encountered a blitherer who declared that, since scientists had been wrong about eugenics, we could not trust them. A similarly-minded person pointed out that some scientists had in the 1970s warned us of the danger of global cooling. The key concept to understand here deserves its own special typographical treatment:
What you read in the newspapers isn’t always true.
Science is not what is reported by the newspapers. Science is what goes on in the journals and conferences of the scientists. It’s easy to be misled by newspaper stories. Some crackpot cooks up a hairbrained idea and calls a reporter. The reporter asks an eminent scientist to comment. Then he publishes both versions side by side. Isn’t that fair?
Newspapers don’t publish the truth, they publish what’s exciting. As a newspaperman once rightly pointed out, they don’t publish stories about airplanes that land safely. And newspapers are not in the business of refereeing scientific controversies. All they can do is consult two sides and report what the two sides say. In the process, you can get a pretty distorted view of what’s really going on.
Scientists, being human like the rest of us, are just as fallible as the rest of us. Individual scientists can screw up just as badly as anybody else. That’s why science does not rely on the judgement of any individual, but instead relies on the collective judgement of large bodies of scientists. We do the same with criminals. We don’t permit the judgement of a single citizen send a man to execution, but if every member of a jury says he’s guilty, we’ll execute him. Well, scientists are even more careful than lawyers: they prefer to rely on the judgement of hundreds or even thousands of scientists.
The claims that “scientists” have been wrong before are based on the statements of individual scientists, not large groups of scientists. The widely-reported claims that we might be facing global cooling were the work of a single scientist, and never enjoyed the support of any significant group of scientists. The same thing goes for scientific support of eugenics, an oft-cited example from the ranks of the global warming deniers. Yes, there were some individual scientists who supported the idea during the 1920s 1930s. Some fairly prominent scientists thought that eugenics was a good idea. But that doesn’t mean that scientists as a whole supported eugenics. The global warming deniers produce quotes from some scientists from that time period, but they offer nothing in the way of citations from the scientific literature.
Recognizing the importance of distinguishing between the opinions of small groups of scientists and the overall judgement of the society of scientists, a great many scientific organizations have been formed to provide society with reliable scientific judgements on a variety of issues affecting policymaking. Foremost among these is the National Academy of Sciences, established by Congress to provide the best possible advice on such matters. The NAS, through its many daughter organizations, can assemble the finest scientific talent in the country to consider any scientific issue. It zealously guards its reputation by insisting that its reports represent only the broad consensus of scientific opinion. There is no more reliable source of information and judgement on the science behind any policy question than the National Academy of Sciences. And their judgement on this matter is clear: their latest report declares flatly that global warming is real, that humans are causing it, and that it will bring serious consequences in the future.
“The costs of abatement are excessive”
Yes, the costs are high – but we don’t make policy on the basis of costs alone. The only metric for policymaking is the comparison of costs to benefits. Citing the costs without considering the benefits is idiocy.
Unfortunately, with global warming, the benefits all take the form of obviated damages. In other words, we don’t gain anything by stopping global warming, but we stand to lose a great deal by failing to do so. So what might those costs be?
At this point, everybody on both sides of the issue makes the same mistake: they concentrate on the spectacular effects. Glaciers melting; rising sea levels swamping island nations; jungles turning into deserts; horrendous weather. Yes, there will likely be plenty of spectacular consequences of global warming. However, we don’t need to concentrate on those big-ticket items. The small, mundane issues will probably be more destructive in the long run.
Here’s a simple, dumb example. Just last week we had a thunderstorm in my area. Now, in many areas, thunderstorms are common, but not where I live. Yes, we get some late summer thunderstorms with some lightning and a spatter of rain, but that’s about the extent of it. The thunderstorm that hit us last week was a record-setting monster, dumping two inches of rain in about 30 minutes in a small area near where I live. It wrought havoc, because none of our infrastructure is designed to handle that much rain in so short a time. Huge surges of water overflowed drainage ditches and ripped across dirt roads, cutting deep trenches and carrying away tons of road gravel. The result was a muddy mess. Every one of my neighbors who has a dirt road took damage. Every one of them had to cobble together some immediate repairs and arrange for long-term repairs. Gravel trucks rumble down the road with fresh loads of gravel. Tractors and bulldozers are busy regrading the roads. How much damage was done? I can’t say, but I’d guess that the average cost to each of my neighbors was probably in the range of a few hundred dollars. The total number of landowners affected was probably less than a thousand, so the total damage was on the order of a hundred thousand dollars – not much on a large scale.
But remember that this was just one storm in one small section of one county of one state in the country. Sure, thunderstorms won’t do any damage at all in other parts of the country – but there will be other effects. What happens when Florida gets hit with a freeze worse than anything they’ve ever experienced? What damage will be done to the citrus crops there? Or what if global warming produces just one additional Category 5 hurricane each season? A typical Category 5 hurricane inflicts tens of billions of dollars in damages. Or how about a nasty cold snap in California that freezes water pipes in millions of houses not insulated against that kind of cold? Or a heat wave in the Northeast that creates impossible demands for electrical power for air conditioning, causing power outages, destroyed transformers, and killing thousands of old people, as happened in Paris a few years ago?
People seldom realize how finely tuned our infrastructure is to local weather conditions. We live in a complicated society with trillions of dollars worth of infrastructure, and all of that infrastructure was designed to work in the prevailing weather conditions. If those prevailing weather conditions change, the infrastructure is suddenly inadequate and it breaks down. When the infrastructure breaks down, economic damages can be catastrophic. And altering the infrastructure to handle different weather conditions can cost trillions of dollars.
I tossed together this quick list of expensive possible consequences of global warming. None of them are spectacular; yet each of them could cost us billions of dollars over the years. Add up all these factors and ask yourself whether it’s worth it to halt the advance of global warming
flood damage to roads and houses
lightning damage to structures
loss of orchards due to changing average temperatures
change of weather requires changes in crop planting, requiring new farm equipment
diminishing soil moisture makes agriculture in some areas unproductive
changes in rainfall make some irrigation systems useless
lower minimum temperatures damage plumbing
higher maximum temperatures require additional air conditioning and more electrical power production and transmission
rises in sea level require alterations in port facilities
rises in sea level require increased expenditure on seawalls
rises in sea level cause seawater incursion into freshwater sources, requiring additional investment in water supply and sewage systems
temperature changes alter ecosystems faster than they can respond, leading to local ecosystem collapse
weather changes wipe out critical predator species, leading to population explosions of noxious insects or weeds.
Note that none of the items in this list are Hollywood-style catastrophes. None of them will ever make the evening news if and when they happen. They’ll just be part and parcel of the ever more expensive grind, lowering overall productivity and sapping our economy.
“Hold on: why are you listing cold as one of the effects of global warming?”
Some people think of global warming as a uniform increase in temperatures all over the globe. But global warming will produce exceedingly complex results, and the single best word to describe all these results is “complicated”. As the global weather system shifts suddenly, we’ll see all manner of changes. For example, it is likely that the Gulf Stream will shift, weaken, or disappear. This ocean current carries huge volumes of heat from the Gulf of Mexico to Europe, making Europe much warmer than it would otherwise be. London is further north than any of the lower 48 states of the USA, yet is considerably warmer than North Dakota or Minnesota. Global warming could kill the Gulf Stream and cause London’s weather to revert to something more typical of its latitude.
In the same way, global warming will bring changes of all kinds to different countries. In general, global warming will have greater effects at high latitudes than at low latitudes and will generate bigger storms and more rain. However, some places will get colder; some will have less rainfall; some will experience fewer storms. It’s very difficult to say how any given location will be affected by global warming. But it’s safe to say that most people will end up with weather that’s different from what they’re now prepared for.
Global warming is a serious problem, but even more serious, in my thinking, is the intellectual dishonesty used in denying it. Global warming deniers are of the same feather as Holocaust deniers. The truth is blatant, the data overwhelming, but they continue to spread their lies. If we let these dissemblers influence our policymaking any longer, we will pay a high price for our foolishness.