The U.S. now has two coal-burning power plants that avoid dumping carbon dioxide into the air. Petra Nova in Texas and Kemper in Mississippi use technology to stop CO2 in the smokestack and before combustion, respectively. Unfortunately, that makes two out of more than 400 coal-fired power plants in the U.S., the rest of which collectively pour 1.4 billion metric tons of the colorless, odorless greenhouse gas into the atmosphere each year. Even Kemper and Petra Nova do not capture all of the CO2 from the coal they burn, and the captured CO2 is used to scour more oil out of the ground, which is then burned, adding yet more CO2 to the atmosphere. The carbon conundrum grows more complex — and dangerous — with each passing year.