The Sierra Club, synonymous with the start of the United States’ large-scale preservation movement in the late 19th century, is now looking toward the future with a report it released last week.

The report is part of the organization’s Ready for 100 initiative, which launched in 2016 and challenged 100 cities in the United States to move from “dirty, outdated fossil fuels, step up, and commit to 100 percent clean energy,” according to a press release. It outlines 10 case studies examining cities making positive change.

A total of 16 U.S. cities have since signed on as part of the commitment, in which the Sierra Club is working with mayors, CEOs, pastors, principals, civic and community leaders, parents, and students to “commit to solutions that help us achieve 100% clean, renewable energy across the United States by 2050.”

When setting these types of goals, it’s key to define the term “clean energy,” which the Sierra Club uses to refer to “carbon- and pollution-free energy collected […]