Looking at the amazing rate of deforestation, not to mention the threatening of almost every other habitat, due to humans/global warming, that sounds very, very possible.
(no I didn't know that, I thought most of the oxygen came from the Amazon :P)
I think the world will plunge into chaos once money ceases to mean anything, we will go back to the struggle to survive that all living things are part of. Imo we have kind of destroyed ourselves. The Earth, as in the planet itself, is fine, but all life on it is going to struggle for survival. I don't think this will happen in our lifetimes.. but I do not envy the generations to come at all. If anything, I envy my father's generation.