[Steve Van Doorn]

Actually the amount of CO2 they are talking about would actually warm the planet.
Right now we have 0.03% CO2 they are talking about +13% CO2 (toxic levels) or 350 times more CO2 then we have today.

[Ragnar54]

Actually, it wouldn't. Co2 is not a magical mirror reflecting all infrared. It absorbs and reemits radiation of certain specific frequencies (that is how astronomers detect CO2 in a planetary atmosphere). The reemitted radiation is not guaranteed to be toward the earth; most of it will head into space or be absorbed by another molecule. Even at 13%, the mass of CO2 in the air could not hold enough heat to warm the planet to any significant extent. The water in the oceans is a different story.

There was an article on FR a while back that compared the AGW theory to attempting to warm your bath water by turning up the heat in the bathroom.

[JustDoItAlways]

To end the Snowballs, I’ve calculated CO2 levels would have had to increase to between 286,000 ppm (29%) to 800,000 ppm (80%) (and even more but that wouldn’t make mathematical sense unless the volume of the atmosphere increased as well).

There is not enough volcanic emissions of CO2 to come even close to those kind of numbers over even tens of millions of years.

The only estimate of CO2 at 715 million years ago is 6,000 ppm and the only one at 635 million years ago is 12,000 ppm.