“Green Cities” is the focus of the 44th annual observance of of Earth Day.

Happy Earth Day! Today is a time to celebrate the beauty of nature and the great outdoors—and to call attention to the environmental effect we have on our planet.
More than half of the world’s population lives in cities. And this Earth Day’s Green Cities” theme is marked by a call for city officials in more than 190 countries to focus on eco-friendly urban revitalization. Although there is no official criteria for ranking the greenness of a city, several factors come into play, including air and water quality, amount of public green space, renewable energy use, efficient recycling and disposal of waste, LEED green-building certifications and access to natural and sustainable lifestyle products and services.
From community gardens and natural food movements to energy conservation plans and carbon offset initiatives, municipalities large and small are making efforts to become cleaner and greener places to live. But some notable standouts are going above and beyond to create a higher quality of life for their residents.
Here are our picks for the 20 greenest cities across the country and around the world (and examples for others to follow).
In the United States
Portland, Oregon
San Francisco (and neighboring Berkeley)
Seattle
Denver
Boston
Philadelphia
Detroit
Chicago
Burlington, Vermont
Billings, Montana
Internationally:
Tianjin, China
Oslo, Norway
Reykjavik, Iceland
Barcelona, Spain
Copenhagen, Denmark
Stockholm, Sweden
Vancouver, Canada
Birmingham, England
Adelaide, Australia
Belo Horizonte, Brazil
For more information, visit earthday.org.
Is your city (or one near you) going green?
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