San Francisco today announced a plan to cut greenhouse emissions to 20% below 1990 levels by 2012. SF government, businesses and residents are currently responsible for 9.7 million tons of CO2 annually, which i left unchecked will likely grow to 10.8 million tons by 2012. This plan will try to bring SF down to 7.2 million tons by 2012, a level below what the Kyoto plan would have required. The "Climate Action Plan" is now online (PDF).
The proposal stops short of declaring San Francisco a global-warming-free zone; it does list several ways to slash the city's greenhouse emissions by 2012 to a target level set at 20 percent below 1990 emissions.
Most steps emphasize voluntary incentives and demonstration projects designed to coax more people out of their cars and onto bicycles or buses; convert as many city buildings and vehicles as possible to green power; expand use of energy-saving construction designs; and reward more recycling efforts.
If San Francisco is alone in this plan, the overall change to the course of global warming will be... not much. But SF isn't alone: 150 cities and counties in the United States are taking part in similar plans, as are 600 local governments around the world. These efforts are coordinated by the International Council for Local Environmental Initiatives (ICLEI) Cities for Climate Protection campaign.