From SPUR:

Proposition A in 2007 tasked the San Francisco Municipal Transportation Agency  with developing a Climate Action Plan to reduce greenhouse gases from the transportation sector, which accounts for half of all emissions in San Francisco. Join Peter Brown of the SFMTA, Timothy Papandreou from the SFMTA’s Sustainable Streets program and Liz Brisson, of the San Francisco County Transportation Authority, to hear about the strategies the City is pursuing to reach its goals.