As a recent resident of Chicago, I saw Mayor Daley's commitment to green construction in public construction, as well as local building codes, serve as a driver in green development.
Stop strip cutting for every house and development project! Stop issuing building permits for small strip malls, shopping centers, and office building which remain mostly empty for months or years after completion. Tear down empty and abondoned buildings and complexes and reclaim the land.
Finally, build a mass transit system that actually goes where the people need it to go.
End urban sprawl, require LEED certification on new buildings, STOP letting developers clear cut forests to build cookie cutter houses, more street level retail (encourages walking) , give tax incentives to people who buy energy star appliances, Green roofs, Increase Environmental education at CMS, more parks Uptown, attract environmental home stores to the area (The Environmental Home Store, Ecohaus, etc.), community involvement.