Minneapolis' many green spaces helped it garner a 10th-place ranking as one of the most sustainable cities in the United States and Canada, according to a study released Thursday.

The Green City index looked at 27 metropolitan areas in both countries and gave rankings based on environmental performance and policies in nine categories. Minneapolis ranked second in land use, and high in the water category, which looked at water consumption and policies on water quality. It also fared well in the waste category, which looked at how much municipal waste is recycled as well as waste reduction policies.

"Our commitment to sustainability guides all of our work, and it shows," Mayor R.T. Rybak said in a release.

Mike Christenson, director of community planning and economic development for the city of Minneapolis, said a good ranking on the Green City index is more helpful to the city's economic development than good marks in other quality-of-life surveys. That's because the index measures city attributes such as reserved bike trails for commuting and an "environmentally friendly downtown" that are popular with younger executives.

"There's a growing group of people who choose sustainable lifestyles on their own," Christenson said. "For the purposes of attracting talent, especially among younger executives, the Green City index may be influential."

But Minneapolis still has room for improvement.

"One of the really low points for Minneapolis is its CO2 emissions," said Tony Nash, one of the study's authors and the global director of custom research at the Economic Intelligence Unit, the research arm of the Economist Group, which publishes the Economist magazine. "There are some real air quality issues that could be addressed to help make improvements."

Alison Taylor, chief sustainability officer at Siemens Corp., which commissioned the study, said Minneapolis should develop more green-certified buildings, a category in which Minneapolis ranked 18th.

Implementing green policies "often leads to a lot of jobs," Taylor noted.

San Francisco ranked first in the study, followed by Vancouver, New York, Seattle and Denver. Detroit ranked last.

Marissa Evans • 612-673-4211