San Francisco, California

When it comes to proper waste disposal, air quality, carbon emissions, eco-friendly buildings, and transportation, San Francisco has become a role model as one of the most environmentally-conscious cities in the United States as well as in the world.

In fact, a 2021 report from WalletHub ranking America's greenest cities put San Francisco in second place, right behind San Diego. The City by the Bay had already ranked first place in 2017 and then second place the following year.

San Fran's commitment to environmental sustainability has made the city a pioneer in the movement. In 2007, it became the first U.S. city to ban plastic bags. Then, in 2014, the city took another step toward tackling the issue of plastic pollution and became, once again, the first city in America to prohibit the sale of single-use plastic water bottles.

A couple more interesting facts is that San Francisco sends less trash to landfills than any other major city in the U.S. And thanks to eco-conscious governmental policies, San Franciscans now use the least amount of water in California.

San Francisco has also embraced a sustainable approach to tourism. Restaurants are dedicated to the farm-to-table movement and often have menus that vary by the season, while more than 1,000 hotels have been ranked as eco-friendly.