Cliff Notes version: Trying to get into heaven is a good thing, even if heaven doesn't exist
In the 17th Century, famed philosopher and mathematician Blaise Pascal endeavored to come up with a logical reason to believe in God. His reasoning was elegantly simple: if believing in God prevents you from eternal damnation and not believing in God has no greater benefit, any rational person should believe in God. In other words, the downside to disbelief is so great that it is logical to avoid the possibility altogether. In this way, he framed the religious debate over God as a debate over the severity of the danger rather than the nature of the evidence.
Anyone who is familiar with the politics of the AGW debate should also be familiar with this argument. Just as Pascal postulated that there isn't much to be gained by wagering against God, many AGW alarmists--the word "alarmist" is troublesome, I know, and I don't mean to insult people who have strong opinions about AGW, but the more neutral "AGW advocates" sounds like there are people out there advocating for more warming--argue that it is only logical to assume manmade global warming is real and that we have to do something about it, because there is no harm if it turns out AGW is false. It's a persuasive argument, too. How can it be bad to move to a cleaner energy infrastructure? Where's the downside to building more fuel-efficient vehicles or lowering our dependence on foreign oil? On the other hand, if we do nothing and AGW is real, is the global climate going to turn against us so violently that we will be unable to recover?
Let's look at the AGW debate from this perspective. Instead of trying to sort through the evidence for or against manmade climate change as I've been doing thus far, let's treat it like a 50/50 proposition, just for the sake of rhetoric. Pascal looked at God as a risk-benefit analysis, so let's apply the same logic to AGW. First, let's look at the potential risks of acting on AGW, and then let's look at the potential risks of not acting on it. This exercise is not meant to say anything about the existence of AGW; it is merely meant to meet the most compelling alarmist argument on its own terms.
Turns out the sun is a big ol' racist: it hates white
So where's the downside to acting on AGW? It all depends on how drastic the action is. On one end of the spectrum, you have the proposals of the Copenhagen Consensus Center's Climate Change Project, which tries to look at AGW from a welfare economics point of view. The Copenhagen Consensus Center looks at all the environmental problems facing the world and prioritizes them by how much good we can do with a limited pool of environmental resources, both financial and political. When looking at manmade climate change, the CCC recommends only the cheapest solutions that have the greatest chance of working and the fewest potential downsides. The CCC recommends things like carbon storage and cloud whitening (might not be as crazy as it sounds), which would have few side effects. There are always concerns, however, as any attempt to strongarm the climate could have unforseen consequences like changing rain patterns or overdoing the cure. AGW denialists would have you believe that these potential side effects are unacceptable, but they aren't really outside the realm of adaptation.
In the middle of the spectrum are familiar political efforts to do something about the climate, things like cap-and-trade laws (emissions trading) and the long-dead Kyoto Protocol. It's difficult to say what the impact of carbon trading would be. The closest the US Government has come to enacting a cap-and-trade scheme, the American Clean Energy and Security Act of 2009 (which passed the House but failed in the Senate), was rated by the Congressional Budget Office as deficit-neutral, though fairly inefficient. Opponents of the Bill argued that energy companies would react to it the same way they would an energy crisis, which would cause a deep and painful recession, potentially much worse. As for international efforts like the Kyoto Protocol, it would be unwise for any nation to sign on when other emerging nations--most notably China--refuse to do so. In effect, if the United States had agreed to Kyoto, it would have hampered its economy at the same time as China's economy boomed, in effect causing a drastic restructuring of the world's power balance and doing little to ultimately curb carbon dioxide emissions (since China would take up the slack with increasing growth).
On the extreme end of the spectrum, you have a small minority of zealots who argue that we need to completely dismantle our economy and rebuilt it from the ground up. Larry Lohmann, for example, writing in New Scientist has argued that the only solution to AGW is "nothing less than a reorganisation of society and technology that will leave most remaining fossil fuels safely underground." Far from just adding carbon sinks or engaging in emissions trading, people like Lohmann think the problem is so fundamental that the solution has to be incredibly drastic. Needless to say, a radical reorganization of society and energy infrastructure would cause immense stress--economic, social, and political--especially if it is done quickly.
If we replace all gas stations with these things, where will I get my teriyaki turkey jerky?
Simply changing how we drive our cars, for example, could have disastrous consequences. Car companies, repair shops, and parts stores would be forced to adapt to the sudden change or go bankrupt overnight. We'd have to dismantle gas stations, rewrite laws, force people to buy new automobiles, and restructure truck delivery, the very backbone of our economy. And new technologies wouldn't have adequate time to develop, which would make new cars more expensive and less reliable. (Also, there's the nagging problem that electric cars get their energy from power plants that emit CO2--thus doing little if anything to cut down on CO2 emissions--but that's not relevant to the current discussion.) The damage all this would do is incalculable. However, if the change is gradual and naturally driven by market forces instead of political ones, the damage would be minimal as new, innovative companies crowd out the old, stubborn ones in an all-too-familiar ballet of capitalism. In fact, in the long run, drastic change to the world's economic models is inevitable and unavoidable, even in the absence of AGW.
What's the downside to inaction, then, if AGW is real? This, too, is not an easy question to answer, as opinions range from the mild to the extreme, even among true believers. A lot of this has to do with how well the Earth can compensate on its own, which was the subject of the previous installment. As I concluded then, the science on that particular point is highly contentious, and a good consensus for it is elusive.
The best case scenario is that the Earth heats up very slowly, ocean levels rise a little bit, and air conditioning costs go up, but the Earth is able to cope with almost everything else. While denialists are quick to point out that people in Alaska might benefit from a little warming--that warmer temperatures tend, historically, to be markers of prosperity--we have to acknowledge that we have built our society and our cities under the assumption that the climate will not undergo any drastic shifts. Indeed, even a slight rising of sea level would be a non-trivial problem for coastal cities (like, for instance, most of Alaska). Having said that, though, humanity is well-known for its ability to adapt to gradual changes, so if the climate doesn't do anything too violent or unpredictable, we'd probably do just fine.
You maniacs! You froze it up! Ah, damn you! God damn you all to Hell!
On the other hand, there's always the possibility that changing climate patterns could be so unmerciful, so chaotic, and so abrupt that we'd be facing global catastrophe if not extinction. This is the extreme danger, the danger so severe that many argue it supercedes any skepticism, just as Hell is so scary that Pascal could not imagine how any rational person would choose not to believe in God. It's easy to find scientific research that adds to a litany of horrors, from pandemic increases in malaria and oyster herpes to a wave of natural disasters akin to Hollywood's climate change parable, The Day After Tomorrow. If even one tenth of all the negative predictions come true, we're in for a world of hurt. I'm not convinced that all this research is compelling (that's the subject for another installment), but I admit it would be foolish to write it all off as unwarranted paranoia.
Just as Hell is not impossible from a purely scientific or rational perspective (there's no data either way), one cannot ignore that the possible downside to not acting on AGW could be nightmarishly bad. Still, the problem with Pascal's Wager is that it downplays the possibility that believing in a fictional God could have its own consequences, just as the AGW alarmist argument downplays the possibility that acting on climate change could do harm. At the end of the day, then, the logic falls apart in both cases.
It is a well-known and well-accepted scientific precept that "extraordinary claims require extraordinary evidence" (that's Carl Sagan rewording Marcello Truzzi). If science operated on a different maxim, that the severity of the potential danger outweighs the necessity of evidence, the Enlightenment would have looked very different and the world we live in today would be dominated by pseudoscience, superstition, and nonsense. Pascal's Wager is, in essence, an appeal to fear, not an appeal to reason, and the AGW position that it's better to do something than to not do something is no different. It's true that, if we combine the worst case scenario with the most rational approach, it seems far more prudent to act than to not act. However, if we combine the best case scenario with the most extreme approach, no rational person would choose to act. That's why we cannot rely on logical sleight of hand to make this decision; we can only rely on evidence. Otherwise, this debate enters the realm of faith, not reason.