That`s a big question.....my garden was mainly laid to waste by weedkiller, but I don`t think that will be the case for the whole planet! There are so many factors involved here, it could be a man made problem, climate change could be the end of all living things...although I expect the changes we are seeing to some degree are partly a natural occurence and not completely manmade. We could see a catastrophe on the scale of whatever wiped out the dinosaurs. We may even be wiped out by an alien with a death ray, thats kinda my favourite....but I don`t doubt that at some point the planet will die, everything dies. Look at our neighbour, Mars (the planet), that`s probably the future. Who knows. What`s your theory?