Helping Keep America's Climate Change Pledge.

Global emissions of greenhouse gases need to fall rapidly to keep warming limited to a maximum of 1.5 degrees Celsius (a level that already risks disruption to ecosystem and human livelihoods). But we're not even close to a path that would achieve this goal, and the U.S. federal government's progress has slowed.

According to "Accelerating America's Pledge" (the third in a series of reports from America's Pledge--a group that brings together private and public sector leaders to ensure the United States remains a global leader in reducing emissions and delivers the country's climate goals of the Paris Agreement --and published by Bloomberg Philanthropies), expanding state, city, and business actions alone could lead to significant reductions by 2030.

American coalitions of states, cities, businesses, and others committed to climate action in support of the Paris Agreement are massive and globally significant. They now represent almost 70 percent of U.S. GDP, 65 percent of U.S. population, and more than 50 percent of U.S. emissions. If they were a country, these U.S. coalitions would have the world's second largest economy--larger than China's economy and second only to the entire United States itself.

Transforming our politics and our energy economy will require broad citizen mobilization, increased energy productivity, disruptive innovation, new market structures, and forward-thinking investment, the report says. "If well-planned and implemented, the required rapid change could bring broad-based economic gain. In part because almost all clean energy technologies will cost consumers less than their current fossil-fuel competitors well before 2030, and many are already cheaper today, the transition to a low-carbon economy will enhance prosperity and lower costs."

A number of local government strategies were highlighted in the first report of the series, "Fulfilling America's Pledge: How States, Cities, and Businesses Are Leading the United States to a Low-Carbon Future." It noted that current efforts by states, cities, and businesses are yielding significant results in...