On Dec. 5, the U.S. Senate will begin marking up a bill that would, for the first time, put mandatory limits on the gas emissions that are warming the planet. The bill, sponsored by Senators John Warner (R-Va.) and Joe Lieberman (I-Conn.), imposes caps on the amount of carbon dioxide allowed to spew from power plants, cars, and others sources. It would also permit companies that cut more emissions than required to sell their excess reductions to those that can't afford to meet the limit. Economists say this sort of cap and trade scheme, which has worked well in reducing acid rain-causing pollution, could help the economy slash emissions at the lowest possible costs.
Meanwhile, delegates from around the world are meeting in Bali, Indonesia, trying to hammer out a global agreement to cut emissions. One of the biggest stumbling blocks: the perceived high costs.