Is it the sun, not carbon dioxide or anything else that is driving changes in the climate

12 21 12 will seem just like the day before , but it is the day ( mostly man made ) atmospheric CO2 levels hit 400 ppm . this is the tipping point after which the earth goes into a slow IRREVESIBLE greenhouse effect . by 2017 after 5 years of worldwide crop failures , food will be made from people . it won't be much longer after then that the seas and atmosphere will boil off into space . money won't help , the deniers die too .

No, since there hasn't been significant change in the sun and there has been an enormous change in CO2 content in the atmosphere.

Something that's changing is a more plausible candidate for the cause of a change than something that isn't changing.

The sun can definitely be ruled out as a cause of climate change.
It's energy output has remained steady for a long time.

It is CO2.
CO2 levels in the atmosphere at historic high levels.
CO2 is a greenhouse gas.