A New Greenhouse-gas Emissions Market Emerges

"Although the United States is not a signatory of the Kyoto Protocol, an international treaty that imposes mandatory greenhouse-gas reductions beginning in 2008, a growing number of cities, states, and businesses are developing market-based programs to buy and sell pollutants that contribute to global warming. These initiatives include underwriting clean energy technology or purchasing carbon offsets generated by planting forests or recapturing methane gas released from cow manure.

...Individual buyers cannot participate in the CCX. But because DriveNeutral is an associate member, it buys blocks of credits and divides them into increments tailored to fit the ecological footprint of an individual automobile. The $25 Castleman paid to offset her Infiniti reflects the current price of carbon, about $1.50 per metric ton."