CO2

I've met a few Lefties who have looked at the global warming data and understood that we have had ten years of no warming with the past year showing significant global cooling.  Some Lefties are capable of  using empirical evidence.

Just for my own records, I want to note the petition from 32,000 people, most of whom are scientists, who point out the error of the global warming hysteria.

To me, the most absurd part of this hysteria is the idea that we should reduce the amount of CO₂ we produce.  CO₂ production varies over millennia and the planetary biosystem accommodates it.