Global warming, in my opinion is not a threat at this time. It was elaborated upon in recent years simply because scientists have conducted experiments. They did not conduct the experiments decades or centuries ago so we do not know how much the weather has fluctuated, polar ice caps melted, etc.
Scientists have now claimed global warming may be caused not by the CO(2) greenhouse gases but by a shift in the orbit of the Earth causing it to move around the Sun in a slightly closer orbit. Some have theorized that asteroids colliding with distant planets in our Solar System such as Neptune have caused a chain reaction moving the planet's orbits closer to the sun.
How many of you could have believe the second paragraph? It is completely false and something I made up. Now, continuing on to my point. People will believe anything if you find any evidence that pertains to your story. Now I am not at all saying global warming is not occuring; what I am saying is that it is not a threat and will not threaten Earth for millions of years, maybe more.
BTW: Al Gore. You suck and I hate you. You did not invent a toaster, let alone the internet you ignorant man.