John McCarthy, one of the pioneers of Artificial Intelligence, has an interesting page on the sustainability of human progress. He argues that we oughtn't be afraid of Earth's increasing population, nor of eventually running out of oil. I was surprised to find out that he is a skeptic about global warming (search for "global warming" on this page). He is now the second prominent scientist that I know of (after physicist Freeman Dyson), who thinks that the fear about global warming is unwarranted.
On the other hand, John McCarthy does say the following:
As I have read more about climate change, I have become convinced that I cannot learn enough about the subject to be entitled to an opinion on my own.