Next June, the United Nation's World Environment Day conference will be held in the US for the first time -- in San Francisco. The theme is "Green Cities: Where the Future Lives":

This is timely because the 21st century marks the fist time in human history that the majority of the world’s population will live in urban areas. Today, cities consume 75% of the planet’s natural resources. As urban populations grow, it is increasingly important to balance the needs of the environment, the economy, and social equity if we are going to achieve a way of living that can support our planet and our people into future generations. ... Each day of the 5-day event will focus on specific theme: Urban Power (energy, renewables and energy conservation), Cities on the Move (transportation), Redesigning Metropolis (waste diversion and the built environment), Pure Elements (food, water and air) and Flower Power (open space, biodiversity and greening the urban environment).