Like me, you may have been wondering how this "pounds of carbon" business works. Certainly, there is some chemistry involved to determine that material is being ejected into our skies. After all, it would be kind of hard to miss little bricks of carbon flying out of tail pipes and smoke stacks.

So here's a pretty good piece from a year ago at TerraPass that explains "How to turn 6 pounds of gasoline into 20 pounds of carbon dioxide."

Short answer:

When you burn something, it might feel like you’re turning it into lightness, air, nothingness. But what you’re really doing is simultaneously vaporizing it and chemically bonding it with oxygen in the air to make it much heavier than it was in solid form.

There, now you won't feel embarrassed when your friends are talking up carbon trading schemes at the next cocktail party, which, by the sound of it, is sure to be riveting.