Not worried enough yet? Brace yourself for the lecture "Arithmetic, Population and Energy" by Dr. Albert A. Bartlett. He starts out by claiming that "The greatest shortcoming of the human race is our inability to understand exponential function", and after heard him prattle on, you will agree.
I normally have a problem with those who, for environmental causes, ridicule the idea of continued economical growth. A society without growth, I feel, is a society where the only way for an individual to improve his or her lot is to take something from someone else. So there has to be some kind of growth or society will disintegrate completely.
After listening to Bartlett, however, it does seem as if "no economic growth" is pretty much around the corner anyway. So it's time to prepare oneself.