In the US, the Greenest Cities are the Best Cities

Popular Science has just come out with rankings on the most energy and environmentally proactive cities in the country. Taking into consideration four factors: (1) clean/sustainable electricity generation; (2) transportation; (3) green space; and (4) recycling, here's the top ten from the list of fifty:

1. Portland, OR
2. San Francisco
3. Boston
4. Oakland
5. Eugene, OR
6. Cambridge, MA
7. Berkeley, CA
8. Seattle
9. Chicago
10. Austin

Category winners were also named:

Electricity: Eugene
Transportation: New York City
Green Space: Chicago
Recycling: Lexington, KY

Is it is just a coincidence, or not, that these are all my favorite urban places in the USA?