[EXCERPT: read the whole article, with more in-depth coverage of the individual cities, here. There is also a related podcast. -Ed.]

"'We have the beginnings of a mass movement among municipal leaders,' says Ralph Cavanagh, energy-program co-director for the Natural Resources Defense Council, an environmental group based in New York.

"For cities, the motivation is twofold. All the hand-wringing over climate change has prompted more cities to do their part to contain greenhouse-gas emissions that most scientists believe are causing global warming. In the U.S., more than 700 mayors have signed an agreement to try to follow the Kyoto Protocol's goal of reducing greenhouse-gas emissions -- even though the Senate has rejected the treaty.

"The other major motivation for cities: energy costs, which have more than doubled since 2000. Strapped for cash, municipalities are scrambling to save as much money on energy use as they can.

"Although city governments themselves use a fraction of energy consumed in a municipality, industry experts say they play a crucial leadership role in getting others to conserve."

The nine cities profiled:

• Chicago, IL, USA's green roof program saves tremendous amounts of energy in climate-controlling municipal buildings and has grown so popular that they estimate there are 4 million square feet of green rooftop existing or in the process of being installed.
• Ann Arbor, MI, USA is replacing regular streetlights with LED bulbs; they estimate that replacing "the downtown street lights alone will save more than $100,000 in reduced power costs annually as well as 294 tons of carbon-dioxide emissions."
• Palm Desert, CA, USA worked with two energy companies to put together an unusual incentive plan to encourage energy-efficiency, not just in municipal buildings, but for all residents. In the sweltering desert, newer air conditioners can make a huge difference in energy use.
• Amsterdam, Netherlands avoids huge energy outlays for air conditioning in office buildings by making use of cold lake water in new developments.
• Beijing, China is closing or moving "cement kilns, coal mines and chemical plants dating back to the era of Chairman Mao... so that Beijing could lower its energy consumption per unit of gross domestic product by more than 6% annually by 2008."
• London, UK is moving to more local production of energy, cutting down inefficiencies in transmission and creating opportunities to reclaim waste heat.
• Aspen, CO, USA plans to reduce its greenhouse gas emissions by 80% by 2050. One starting point; instituting a number of energy-saving measures at their recreational facilities.
• New York, NY, USA -- the Mayor has called for large amounts of new clean energy. One source could be the waves in the East River, where a new experimental power station opened last year.
• Thane, India, a suburb of Mumbai, is addressing energy shortages by promoting solar hot water heaters. The city is installing them in municipal buildings, requiring them in new buildings, and offering property tax discounts as incentives for retrofitting existing buildings.

Photo credit: Alexander Svensson