Okay, let's be honest, people who deny global warming has been happening for the past 150 years are a bit delusional. Some might debate about how much of global warming is attributable to human activity and how much is independent of man, but it's happening. Policy makers have been working on this problem for 40 to 50 years. Has it slowed? Probably - and it could certainly be because of the measures first world countries have taken. But global warming is not going to stop. The US, Canada, and Europe have taken measures to reduce impact, but there is still some impact. In terms of human-caused warming, the major global warmers of the future, however, are developing countries. In trying to catch up to first world countries, developing countries care much less about environmental concerns than about economic progress. Alternatively, in terms of natural warming processes, we are not yet at the consistent peak temperature seen in numerous previous ice-age cycles. Whether you attribute global warming to man or nature, there's no stopping it.
The battle is lost. So what should we be doing? Instead of pouring billions of dollars into, and regulating billions of dollars out of, combating global warming itself, we should be spending those billions on preparing for the inevitable. Money should be spent on relocating high risk coastal populations, on building levees, on stabilizing populated coastal terrain.
I'm not saying we should just throw in the towel at slowing global warming, by all means, let's attempt to moderate it. But we must be practical in admitting we can't win, and so put more effort into preparing for repercussions. Let's actually save lives, rather than complain about how lives and cities will inevitably be lost and then watch it happen.