"The U.S. Environmental Protection Agency will directly enforce new greenhouse-gas rules in parts of Arizona after the state refused to submit its own program for controlling the pollutants.

The new rules, which take effect today, add greenhouse gases to the list of pollutants covered under air-quality permits and will eventually require the largest polluters, mainly industrial operations, to reduce emissions."

Shaun McKinnon reports for the Arizona Republic January 2, 2011. [2]