"and human fossil fuel use is very probably one of the big reasons why."
Show me the science that supports your statement.
Logically, Human activity must have SOME effect. If we are pumping more CO2 into the atmosphere, and cutting down trees, producing radioactive waste etc etc, it must count for something...
Personally I think all that Mankind does is dwarfed by other factors but what we do must make some difference. I rate chaos theory.
Global Warming: Brought to you by the same people who brought you Y2K...