We can put a simple question: if human intelligence could develop during one-two millions of years, why it didn't develop a many years before? The answer is, the evolutionary pressure for development of intelligent behavior is quite low in systems of sustainable development. We should realize, human intelligence doesn't allow us to exploit the environmental sources more efficiently - only more intensively.

Even after million years of intelligence evolution, the food & energy consumption of every human creature ISN'T lower, then the consumption of some ape inside of forest. We should realize this ASAP - or all our "intelligence" will become just a temporal malign mutation.