By looking at the data. The warmest decade this century occured during the 1930's, after that, and with a 24% increase of CO2 over the industrial boom era, temperatures actually cooled. The 20th century ended cooler than it started, the arctic ice fields show a net GAIN in total area, as to teh glaciers in greenland, and the ice cap at the south pole. ALL show a net GAIN in mass/ area.
I'll repost this because I can't believe you're trying to tell me that air pollution is good.
Whether the ideas come from wackos or not, clean air and alternative fuels SHOULD be what we work towards. Constant turmoil in the Middle East and breathable air is a good enough reason for me.
What is the downside of lowering pollution and seeking alternative fuels?