Mayors from cities from around the world signed the "Urban Environmental Accords" on Sunday in San Francisco. The non-binding treaty tries to address 7 issues – energy, waste reduction, urban design, urban nature, transportation, environmental health & water - and lists 21 specific actions to make urban areas more green. They even have created a star-coded system to show which cities are doing well and which are falling behind on implementation. After signing the treaty, the mayors went outside to hear a 500-member gospel choir sing a song composed for the event called "Together We Can." I sure hope so.