Mayors Sign Urban Environmental Accords

Mayors from around the world on Sunday signed an international treaty calling for increased use of public transportation and drastic cuts to the amount of trash sent to landfills.
The signing of the "Urban Environmental Accords" capped the United Nations World Environment Day Conference in San Francisco. The nonbinding accords list 21 specific actions that can make cities greener.
San Francisco was the first U.S. city to host the annual conference. Much of the conference focused on global warming and what mayors can do to curb emissions of "greenhouse gases" such as carbon dioxide that trap heat in the Earth's atmosphere.