I just wanted to comment on something Alan (Klein) said (and maybe others) about pointing out the beneficial effects of global warming. I presume that this is meant as a way to present "both" sides of an argument, in much the same way that reporters are supposed to provide a "balanced" view. I have a fundamental problem with that concept. When we teach our children that stealing is bad, should we be also be providing reasons why it might be good too? We need a more sophisticated understanding of "balance", I think.
The point of view that human activity is perturbing the climate in a way that may have runaway consequences is what is being studied (aside from the more basic need to understand the evolution of the earth's climate anyway, which is something we should probably do even if humans were having no measurable impact). Even if more rapid than normal (other than natural cycles) heating means that some areas now under snow might end up being good farmland, that may be temporary, since if we keep heating the place even more, then pretty soon (measured in centuries) those new farms may themselves eventually become dustbowls. Then what?
But there are people who are doing exactly what Alan is suggesting. The Netherlands is making long-term plans to deal with rising sea levels. So is the US military. Others are probably thinking about the infrastructure changes that will be needed if the current southern US becomes a dust bowl and North Dakota becomes warm enough to grow papayas. I'm sure someone somewhere is thinking about these things. But that has nothing to do with determining what effect humans are having on the climate, which is the topic under discussion. In fact, the people making plans in North Dakota need to know about climate change too. There aren't two sides to the "argument". In that sense, they're both on the same side.
Also, I did not bring up the issue of New Orleans and Katrina as an example of what happens when we don't listen to the correct expert advice. I only brought it up in the context of planning for rising sea levels, something which is going to affect a lot of coastal cities, it appears.