Global warming is a reality, and there's simply no debate about that among people with a wit of sense. The ice caps are melting, the sea is rising, and an increasing amount of greenhouse gases are being released from previously frozen tundra every day due to the warming, creating a circular problem.
The only debate is whether man's activities, particularly the burning of fossils fuels, is a significant contributor to the problem, which is largely a natural, cyclical phenomenon. We're coming off a long period of relatively mild weather, and we have some very bad times ahead, at least in the long term. Whether we're accelerating that change is open to debate, but most scientists (as opposed to politicians) say we definitely are.
The impact will be severe, from changing crop production to more violent weather -- there's simply no question about that, beyond when it will occur. This current warming cycle might reverse itself at some point -- unless man's contribution is really a significant factor, in which case, who knows?
On the brighter side, my house is 500 yards from the sand, and at an elevation of about 50 feet, so I may end up with beachfront property! Aren't you happy for me?