Pittsburgh Mayor Luke Ravenstahl signed the U.S. Mayors Climate Protection Agreement yesterday, and his rival, Councilman William Peduto, issued a press release claiming the mantle of green leadership for himself.

Mr. Ravenstahl's signing of the agreement commits him to reducing carbon dioxide pollution in the city to 7 percent lower than 1990 levels by 2012.

Mr. Peduto, the mayoral challenger in the May 15 Democratic primary, noted that he won the Green Building Alliance's Shades of Green Leadership Award last year and the Sierra Club's endorsement in 2005, among other environmental honors and accomplishments.