In my opinion, you are half right. People have been saying the world will end since the beginning of time, and have been setting dates for awhile, one of those dates being in 2012 because that's when the Mayan calender ends or something like that.

But those are from causes we can't explain. We can explain global warming, and if we don't take action to protect our Earth.

People who say global warming isn't real is kind of like if they have a child and the child gets a cut on their finger. They disregard the cut, believing it will heal itself, not bothering to clean it or bandage it. But when the cut turns into an infection, they are still not believing it, because they don't want to admit it's their fault because the child didn't know any better. They wait until the last minute to call the hospital, at which point the child is at risk for a disease because of all the germs in the cut.

If you love this Earth you will go to any measure to protect it, like a child, even if you don't believe it's in danger.