As the United States federal government retreats from energy innovation and environmental regulation, local and regional efforts across the U.S. are scaling up. Cities, in particular, are intensifying their commitments to fighting climate change and are playing an increasingly important role in the sustainability of the planet. One such commitment is the Sierra Club’s ‘Ready for 100’ campaign, which recognizes cities in the U.S. that have formally committed to transition to 100 percent renewable energy.