One inevitable pitfall will be the temptation to be distracted from the discourse of ethics by the details of policy. My students, most of whom prefer technical problems to theoretical questions, will be tempted by this distraction. And since I'm usually so concerned to show that theory matters to practice, I will be too. But it's a lower-level course, not a place for settling what policy should be for specific cases.
Another pitfall will be overcoming both apathy and skepticism. In just about every class or lecture where the question of global warming comes up, there is one (and usually only one) skeptic. I hope that I can pull the ever-present skeptic into a debate on the ethics of the issue instead of the facts. I personally believe the facts are settled, but there is no time in a philosophy course to teach all the science--both basic and complex--that is needed to place trust in the consensus of climate scientists. (For example, one student this year insisted that since Mars is warmer than the earth, and Mars has no humans on it, climate change on earth can't possibly be caused by humans.)
Freeman Dyson has a piece in the New York Review of Books discussing an economic evaluation of climate change policies in the book A Question of Balance: Weighing the Options on Global Warming Policies. The author, William Nordhaus, holds that the more ambitious plans, such as Al Gore's call for a drastic reduction in emissions, will not be cost-effective in the long run. That is, they will cost more to implement than the economy will benefit from climate stabilization. (This evaluation seems to ignore the ethical question of whether the costs of failure to act are disproportionately paid by the vulnerable.) On the other hand, doing nothing could be disastrous. Nordhaus says that any policy proposal which tries to avoid raising the price of carbon (and doesn't that translate into allowing gas prices to rise?) is simply not serious.
Dyson also takes on the question of the global warming skeptics, as I'm sure I'll have to do. The main argument in their favor is the problem of induction that attacks any scientific generalization, plus the philosopher of science's skeptical metainduction: any scientific inference could be wrong, and in the history of science many have been wrong. So maybe the climate scientists, with all their evidence for anthropogenic causes of global warming and the even greater consensus that, human-caused or not, the current warming trend will be fueled by positive feedback mechanisms, are just wrong. Maybe. But the idea of inductive risk does hold that skepticism in check: if we're wrong, we'll be in really bad shape.
Dyson's concern is that the global warming issue distracts from other environmental issues. He writes:
Much of the public has come to believe that anyone who is skeptical about the dangers of global warming is an enemy of the environment. The skeptics now have the difficult task of convincing the public that the opposite is true. Many of the skeptics are passionate environmentalists. They are horrified to see the obsession with global warming distracting public attention from what they see as more serious and more immediate dangers to the planet, including problems of nuclear weaponry, environmental degradation, and social injustice.