“Although San Francisco is green on a daily basis–we have the highest recycling and composting rate of U.S. cities–Earth Day is still a special occasion for us to celebrate nature and the environment. The annual, internationally recognized Earth Day is April 22, but the weekends before and after in San Francisco are busy with Earth-Day-inspired festivities as well. In this guide, find Earth Day activities in San Francisco and the Bay Area, listed in chronological order.”
Earth Day in San Francisco – Events and Activities in San Francisco for Earth Day 2011 via Barbara Koh – About.com