New York City's population topped 8.2 million last year; by 2030 or so it's expected to hit nine million. Where are all these people going to live and work; what's going to power their lights and appliances and elevators? This is the hot topic for Mayor Bloomberg's Sustainability Advisory Board, according to this article by Sam Roberts in The New York Times, buried in this past Sunday's Metro Section (you do read the Metro Section, don't you?).

According to this article, one of the board's big priorities is "how to reclaim as many as 1,700 acres of polluted land — brownfields and other former industrial parcels — and transform them into environmentally sound sites for schools, apartments and parks." Other sustainability questions include:

• how to improve commuting times
  
• maintaining and protecting the drinking water supply
  
• reducing sewage overflow into the city's waterways during storms
  
• how to maintain air quality (as defined how? not clear from this article) in the face of growing energy demand
  

Two major zoning changes (of the Brooklyn waterfront in Greenpoint and Williamsburg and the Far West Side of Manhattan) foreshadow how the board may recommend addressing these problems, according to The Times; both aimed to reclaim "underutilized" land for economic development and increasing the city's property tax base. Both changes were driven by sustainability board chair and deputy mayor for economic development Dan Doctoroff (as part of the City's failed bid for the 2012 Olympics), a man Mayor Bloomberg says "will have a greater impact on this city, I think, than Robert Moses, in a much more democratic world where there’s a lot more community input and a lot more supervision from the courts and the Legislature."

The Sustainability Advisory Board is expected to release its draft agenda this week, and invite comments from civic groups and the public. (The mayor is expected to present the board's final goals, and strategies to achieve them, by mid-2007.) This document is one to watch out for.

WorldChanging readers are some of the most thoughtful and informed advocates of sustainable development there are. So, what are some of your ideas for transforming New York City into an environmentally sound, economically vibrant, and healthy mega-metropolis over the next 25 years?