Right, I'm gonna post my humble opinion, although I promised myself I wouldn't write about this theme anymore. I learned not to hope that the "non-believers" will see the light, it's not gonna happen.
First of all, stop calling it global warming, it's a climate change. It is a FACT that the earth has been heating up in the last decades and especially since the mid 1980's. The last decade there have been more climate records broken then anything. The effect? Ice from the poles will melt and raise sea-levels (read: Holland's f*cked). This icewater will mix with the salt water in the oceans and create an inbalance in the thermohaline circulation (
http://en.wikipedia.org/wiki/Thermohaline_circulation) in the oceans, thus slowing down or even stopping the ocean conveyor belt. And it is this conveyor belt which brings warm water to Europe and it is responsible for the mild climate in most of Europe. So when this conveyor stops, temperatures in Europe will plumit by as much as 10-15° (And you English thought your last winter was already bad :O) All the things I just mentioned above are PROVEN. It is going to happen some day. The arguements (they can hardly be called evidence) contradicting these facts are mostly none existant and the ones that do exist are riddled with mistakes in their calculations and conclusions.
Now what is very important is the question is all this induced by mankind or not. Because if it is, the climate change will happen a lot faster and more drastically then when it's not. There's a lot of evidence to support the claim that we ARE responsible. HOWEVER there's also quite some (decent) evidence that says otherwise. And although there is a lot more evidence to support the claim that we are responsible, we can't say FOR SURE it is the case.
But then I ask the "non-believers" on this forum: Even if the chance is pretty big that you are right, would you be willing to risk that small chance that you are wrong?
In the end, like i said, i stopped trying to convince people that this is actually happening. Because if I'm wrong I'll be happy i was wrong and if i'm right, i'll be happy to know mother earth and it's inhabitants wont be bothered again by the distructiveness of mankind...
PS: For the people who want to know why i dismiss the "evidence" thats claims the earth isn't warming up, I read all of this so called evidence. I'm a scientist at the biggest university of my country and part of my job is to study this very subject. But then again, I'll probably be seen as another dumb scientist by some of you (like I read in posts above)