The "Copenhagen Consensus" project, an effort headed by environmentalist gadfly Bjorn Lomborg to rank global development efforts by cost effectiveness, is under fire for disparaging anti-global warming measures like the Kyoto protocol. Strategies for reducing greenhouse gas emissions ranked dead last on the project's list of proposals, and were singled out, along with "guest worker programs for the unskilled", as "bad" ideas.
Now, I confess to being a bit of a global warming skeptic, for various reasons. But let us put skepticism aside for a minute, and accept the oft-touted climatologists' "consensus" that global warming is at least highly likely to worsen, and at least partly caused by the burning of fossil fuels. It still doesn't necessarily follow that the best approach to dealing with it is to attempt to reduce fossil fuel consumption.
Consider, for instance, snow. It kills thousands a year worldwide (through transportation accidents, strandings, avalanches, and so on), and no doubt costs billions of dollars a year to deal with. Nevertheless, it is not widely believed to be a wise idea to try to mitigate the damage caused by snow by altering the weather (say, by figuring out how to keep snow away from inhabited areas). On the contrary, any such effort, it is assumed, would be bound to be hideously expensive, massively disruptive, and far from certain to succeed. That's because weather is notoriously difficult to change, and has such widespread, varied and complicated effects when it does change that assessing the net impact of any such change is virtually impossible.
Similarly, global warming--even if it is significantly a consequence of human behavior--is likely to be hideously difficult to reverse in a controlled, unambiguously desirable way. By comparison, coping with the possible effects of global warming seems like a far more tractable problem. Expanding deserts? Desertification has been going on for a long time, and all sorts of means are available to combat (or cope with) it. Increasing tropical storm activity and flooding? Again, storms and floods are well-understood phenomena, normally (and far more efficiently) dealt with using evacuations, shelters and barriers rather than by attempts at prevention. Colder winters in some locales? See under: snow.
My strong suspicion is that environmentalists' focus on attempting to reverse global warming itself, rather than mitigate its ill effects, is motivated primarily by an emotional--even religious--aversion to human influences on nature. Because global warming is seen as manmade, undoing it--in effect, returning nature to its supposed pristine state before human intervention--is viewed as desirable in itself, irrespective of the practical costs and benefits. Conversely, coping strategies which simply accept weather as a given are acceptable only when the weather is purely the product of Mother Nature's whims. As far as I can tell, there is no practical reason to make this distinction.