Dec. 7, 2007 California has become the first U.S. state to require industrial polluters to report their greenhouse gas emissions, Reuters reports.

Beginning in 2008, plants that emit more than 25,000 tons of CO2 per year must provide emissions data to the California Air Resources Board (CARB). The annual reports must be independently verified by 2010.

"This sends a clear signal to entrepreneurs, innovators, and venture capitalists investing in cleaner energy solutions, that California is serious about reducing pollution and leading the clean tech industry," Devra Wang, director of the National Resource Defense Council's California Energy program.

CARB's mandate also sets specific emissions targets to achieve a statewide rollback to 1990 emissions levels by 2020.