Climate scientists have been predicting these scenarios for a long time and it is finally catching up to us. You can only abuse the world for so long before eventually you start to make in uninhabitable - in reality once these "runaway train" situations get going it might be past the point of no return. You'll see the North and South ice caps disappear, sea levels rising further and the most extreme ends of the weather occurring more frequently. If we continue to heat up the planet via all our activities, then it's possible that the atmosphere.. a few hundred years down the line will not support human life without assistance. Another tragedy is that all the plant life, insects and animals will also find it very hard to adapt fast enough to these changes so we will see vast drops in diversity.