Global Warming.

I am trying to make some sense of all the conflicting comments around at the moment on this issue. It seems to me that there are four questions -
1. Is global warming taking place?
2. If it is, how serious a problem is it?
3. If it is, to what extent is it being cause by human activity?
4. If it is down to human activity, what can (or should) we do about it?
The only question with anything like a definitive answer it seems to me is question 1. Although average temperatures have been pretty stable over the last decade or so, the general trend over the best part of the last couple of centuries is upwards and there is little doubt that this is causing things like an increase in the melting of the polar ice-caps. As regards the other questions, it is difficult if not impossible to get a straight answer. And I think this is probably because if truth be told, we simply don't know. People are making best guesses, which may prove in the event to be wide of the mark. I've said before that I think that reducing the amount of "greenhouse gasses" that we put into the atmosphere is a good idea in any event, but I question the morality of pushing developing countries back into poverty over what at present are no more than a collection of mainly unsubstantiated theories. Mind you, I'm glad I'm not the one having to take those decisions.