I think the world we live in will certainly look very different in 50 years time if the current rate of pollution continues. The Earth’s temperature will continue to rise, the ice caps at the poles will continue to melt, and it is likely that many vulnerable species of animals will become extinct. Will the world die? I don’t think so, but we will have to live our lives very differently to cope with the change.
One day, many, many million years into the future and long after humans die out, the sun will become hotter and hotter before exploding in a massive supernova and wiping out it’s orbiting planets so Earth will one day “die”.
In the meantime though, it’s down to us as inhabitants of a beautiful planet to look after it. As Jemma says, the green house effect may kill off species but it is unlikely Earth will die due to it.