"Carbon" by itself is a confusing term these days. To us it just means carbon fiber, but in a political context it has a totally different and somewhat negative meaning. Here in British Columbia, the government has recently instituted a "carbon tax." This means that you pay extra for each liter of gasoline, diesel, or propane, and the rate increases each year. Federally, the Liberals are pushing a carbon tax in association with a "green shift" (nobody in Canada understands what Stephane Dion means by this, so don't worry). Also, under a "cap-and-trade" system (coming to California?), you get to trade "carbon credits."
So if we had a carbon level, things would get confusing real fast. Actually, I like the idea of carbon credits. I think I should be able to sell credits and take the cash because I offset the effects of others' driving their cars to work while I ride my bike.
L.