Common sense from an Indiana University geologist who led a study finding that, surprise, surprise, the world has been subjected to dramatic climate change even during eras when humankind was not present to screw things up:
If there are big, inherent fluctuations in the system, as paleoclimate studies are showing, it could make determining the Earth's climatic future even harder than it is," he said. "We're learning our climate, throughout time, has been a wild beast."
Comments
1) Look up the CO2 levels over the last few million years taken from ice cores.
2) Look up the CO2 levels during the 70s.
3) Look up the CO2 levels today.
Let me know what you find...