I have not yet watched Al Gore's dokkie but I have done some research of my own and discovered the following facts on Global Warming:
It's a natural occurance
The following graph is derived from ice core samples and other geological surveys:

If you look at the blue line you will notice that the earth suffers occasional ice ages.
We are currently coming out of one that reached rock bottom a few hundred thousand years ago (around the time man started to get brains).
The earth likes to be at 22degrees. That's a global average of 10degrees hotter than it is now.
What will a world with a global average of 22degrees look like? It will look like Jurassic park of course! (but without the dinosaurs).
Sea levels will be 80metres higher - that means Cape Town is gonners.

The ice will melt, oceans will rise
the currents will change causing new weather patterns and hotter climates.
Water expands as it heats up causing ocean levels to rise even more.
All the extra water will press down on the continents, sinking them and flooding inland to re-create the great inland oceans of millions of years ago. Imagine lakeside properties near Sutherland!
The increased pressure on the continents may also squeeze out some underground reserves causing fresh water lakes in places like the sahara.
Atmosperic heating will cause CO2 to be released from the ice and earth (It's been building up at an alarming rate the past thousands of years)
The extra CO2 is poison to us but fortunately not terminally toxic. Plants will love it and increase in size and abundance.
Gigantic trees and ferns will once again cover the lands like in the days of the giant herbivores such as the Brontosaurs.
The returning forrests and savannahs will produce more oxygen and the air will become thick and stifling. Humans will sweat like pigs and die of lung related illnesses.
Corn and maize crops will fail. Bananas and pawpaws will flourish.
Insects will grow bigger and again compete for food against mammals and other land animals. Imagine a cockroach 30cm long! There used to be plenty of monster insects when the earth had more oxygen 50million years ago. The Triassic period had millipedes 3metres long!!
I'm sure some of you think it doesn't sound all that bad but keep in mind that the transition period will probably be marked by more floods, earthquakes and severe storms.
It won't wipe us out in a short time and we will probably survive until the earth reaches it's optimum temp a few thousand years from now.
Unfortunately many, if not most, of us will die in the next few hundred years.
What does pollution do? Some scientists think it caused the warming. I say bullshit.
Some scientists say it sped the cycle up. I think they may have a point.
Others say it makes little or no difference. That is irresponsible behaviour IMHO. It makes a difference to me, the person who has to breathe your fumes and step in your shit.
Thas was my rant. It was nice knowing you all. Civilization will end as we know it in the next hundred years or so. The human race will probably come out better for it but most of our children will die because we never bothered to prepare for the changes.