From mass transit options to street design to parking provisions, the shape of cities and their transportation systems will help determine oil consumption patterns for billions of people worldwide.

"We believe that carbon neutrality not only benefits the climate, the Copenhageners will gain a lot in terms of increased growth and life quality as well. Cleaner air, less noise and a greener city will give Copenhageners better daily lives and create more jobs."

Send all your eco-inquiries to Jennifer Grayson at eco.etiquette@gmail.com. Questions may be edited for length and clarity. My husband and I are clos...

Which U.S. cities are the greenest? A new report from Canadian-based media company Corporate Knights ranks the country's greenest cities, with Seattle...

Even with the economy struggling to rebound and cities facing unprecedented pressure to do more with less, this year is shaping up to be a busy one for the green cities movement. And the timing couldn't be better.

With these unmeasured factors, city parks with high maintenance regimes may have much larger impacts than reported here. Thus, urban areas that have a large amount of mowed, irrigated, fertilized lawns and pruned shrubs and trees can be a source of carbon dioxide rather than a sink.

One of the key areas where cities can promote sustainability is on the streets. By narrowing roadways and increasing the width of sidewalks, they can encourage more walking, higher population density as well as slow down vehicle traffic and generally make their streets more friendly to multiple types of users.

This week, the EPA released its annual list of the 25 American cities with the highest number of Energy Star certified buildings. According to the...

I regard lawns as bad because they are like concrete to most species and have very little benefit for wildlife. But are lawns bad, considering all the other activities and consumption patterns we urbanites partake in?

Trails, sidewalks, and open spaces not only encourage residents to interact with their environment, but also promote a strong sense of community by facilitating interactions among neighbors.

Trees and plants help cool the city, which reduces the need for energy-hogging air conditioners while also providing valuable ecosystem services like reduced water runoff, filtration, and habitats for city critters.

From EcoSalon: Clean energy, public transit and local food make these 10 big cities the greenest of them all. Honking cars emit foul black cloud...

The world's greatest greening opportunity many not be saving trees, but rather making our cities self-reliant so they are less dependent on the natural order for resources.

We've got to get national leaders off the dime. Here's one way: When city leaders speak out, especially in large numbers, Washington tends to listen.

What's most impressive about Normal leading the pack on sustainability is that the town is, well, normal. Like anywhere, it has residents who want a cleaner environment and need good jobs.

A recent study sought to find the greenest city in the U.S. and Canada. The study was commissioned by Siemens and conducted by an independent research...

Once a big idea is vetted -- whether in an authoritarian or democratic way -- what assures its success? Most particularly, what if, from Day One, the vision pushes comfort zones of the achievable; politically, legally or monetarily?

Could sustainability principles pave the path to peace? President Obama's strategic statements about the Middle East last Thursday (and as clarified ...