What does a sustainable city in the U.S. look like? Current trends in the environmental quality of urban areas may be redefining common concepts of the concrete jungle, as a recent ranking of major metropolitan areas by WalletHub reveals.

The analysis considered a diverse set of indicators to rank the sustainability of the 100 largest cities in the U.S. Metrics addressed greenhouse gas emissions per capita, smart energy policies and the penetration of renewable energy sources, fuel consumption by automobile commuters, accessibility of jobs by public transit, green space and water quality.

The top spot was earned by San Diego, California, which was assigned the highest scores in terms of environment, lifestyle and policy, transportation and energy metrics. Gilbert, Arizona, ranked last on the list.

The lowest greenhouse gas emissions per capita can be encountered in Virginia Beach, Virginia, while the highest levels are found in Corpus Christi, Texas. Lubbock, Texas, has the lowest median air-quality index of 25, which is four times lower than in Phoenix, Mesa, Chandler, Gilbert, Glendale and Scottsdale, Arizona, which are the cities with the highest at 101. Anchorage, Alaska, boasts the greatest amount of greenspace; Hialeah, Florida, offers the least.

View all of the rankings and an interactive map profiling the sustainability of the 100 largest U.S. cities.

Data used to create this ranking were collected from the U.S. Census Bureau, U.S. Environmental Protection Agency, Trust for Public Land, U.S. Department of Energy and various university, nonprofit and private sources.