The main threat to our planet will come when oil stocks deplete. When we have to burn wood and coal for heat, then we shall see polution such as seldom before in our planet's history. THEN, we will have serious issues that make global warming in a hundred years seem like issues we'll have time to solve. Right now, it's our almost complete and total dependency on fossil fuels that is scary. It's a dependency we have that will have to be reversed or seriously curtailed, because the planet cannot take it.