Even if existing environmental measures were more effective, they would be more than offset by the 700 US military bases worldwide and the footprint of the wars in Iraq and Afghanistan. The challenges are extremely complex and require addressing a variety of environmental, economic, social and cultural factors simultaneously. Only a multi scalar transformation, engaging communities, cities, countries and cosmopolitan factors will suffice.

No document illustrates this as effectively as the just released United Nations Human Development Report for China 2009/2010, China and a Sustainable Future: Toward A Low Carbon Economy and Society. Despite the fact that China has already taken more extensive and intensive measures toward a low carbon economy than any other country, the combined severity of environmental destruction and the growth of inequality present a grave crossroads. For example, China will face 350 million new urban dwellers (more people than the population of the United States) in the next 20 years by building 50,000 new high rise residential buildings and 160 new rapid transit systems. In this process extremely difficult choices, reconciling apparent contradictions between a low carbon economy and the steady improvement of human development, will have to be made, both in existing and soon to exist new cities. Ironically, the very market economy that motored the unprecedented growth, has also fragmented the governmental authority required to enforce the legal measures required to synchronize growth and low carbon development. The new 50,000 high rise residential buildings must avoid the pitfalls of the old "block housing" and become "eco blocks," largely self sustaining, with a low input and output footprint. Similarly, entire cities and metropolitan regions must take a similar path. Mayors could simply mandate that all governmental consumption and waste production be 100 percent renewable.

This challenge will require far more than an "earth day," an earth month or year. Rather, it will require profound structural transformations of human relationships to humans, to other species, and to the ecological systems that sustain us. New relationships between states and cities, urban and rural life, national and global identity are required. These perspectives are not as far from implementation today as they were when presented at the first Earth Day. But it has taken 40 years to begin to understand the complexity and difficulty of the choices that must be made. Nowhere are the choices more evident than in China.

Barry Weisberg is living in Shanghai and is the Global Cities Reporter for Worldview, Chicago Public Radio, reporting on the Shanghai World Expo. See http://www.citieschallengeschoices.info/. He was the author of Beyond Repair, The Ecology of Capitalism (1971) and the editor of Ecocide in Indochina, The Ecology of War (1970). Contact: barryweisberg@att.net