Fossil fuels - coal, oil, gas etc. accumulated over millions of years. The human race has dug up a very large percentage of these materials, such that easily accessible reserves of oil, at least, are now much scarcer, and burned them in just a few human lifetimes. It's probable that a major part of this burning has taken place in my lifetime - I'm 65 this year. Surely, we must expect some adverse consequences from such a monstrous enterprise? As I understand it, the second?, third? Law of Thermodynamics says that if you pump more energy into a system it becomes more disordered. Although it's probably too early to tell absolutely, the climate seems to be becoming more disordered.