With global climate change and unstable energy prices becoming some of the biggest news stories of 2007, green cities are a red-hot topic. About 80 percent of the nation lives in urban areas, so no longer are environmental issues confined to forests and endangered wildlife species.

How well a city is prepared for the future and what quality of life it provides for its residents, business and visitors is becoming central to economic competitiveness and real estate valuation. Global climate-change related impacts and mandates further intensify these trends.

For the new book How Green is Your City? (New Society Publishers) SustainLane created its US City Rankings based on how the largest 50 cities compared across areas such as renewable energy and alternative fuels use, green buildings, local food, public transportation use and walkability, housing affordability and natural disaster risk, along with overall sustainability planning and management.

The independent research firm took 2,000 such data and information points from public data, non-governmental organizations and the cities themselves and developed an overall green city ranking.

Said author Paul Hawken in the book’s foreword: "How Green is Your City? The SustainLane US City Rankings is the first systematic report card measuring city quality of life impacts combined with resource impacts….urban sustainability is not an option. It represents prudent governance and provident management by and for the people. A carbon-constrained world is upon us. While international action is required to prevent global climatic catastrophe, cities must lead the way in creating a post-carbon environment where people can thrive.”

More from SustainLane.com

• Green business directory and product reviews
• More US Cities ranked in How Green is Your City?