Watch The Growth Of Cities Using 100% Renewable Energy

As nations drag their feet on even modest climate change commitments, cities continue to take up the slack, particularly in taking up clean energy. More than 40 cities worldwide, including several in the U.S., now get all their electricity from renewable sources, while at least 100 get at least 70% of their power from renewables. Many more have made commitments to go that way in the future.

The figures come from the CDP, which tracks the carbon disclosures of organizations in the public and private sectors. Since the signing of the Paris climate accord in 2015, it has seen the number of cities reporting their climate impacts shoot from 308 to 572. More cities, it says, are taking their climate roles seriously.

“There’s been a sharp rise in environmental reporting since the last time we did this,” says Kyra Appleby, head of CDP’s cities program. “There has been a lot of momentum in U.S. cities in the absence of federal leadership on climate change. You are seeing large cities across the U.S. making the switch.”

U.S. cities already over 70% include Seattle; Eugene, Oregon; and Aspen, Colorado. Burlington, Vermont, is the most renewable, with fully 100% clean electricity already. Atlanta, Georgia, and San Diego, California, are the latest to commit to going to 100% of renewables, joining about 50 others, according to separate figures kept by the Sierra Club.

The role of cities is crucial for fighting climate change, as they account for about 70% of the U.S.’s emissions. The Sierra Club says if the whole U.S. Conference of Mayors, representing 1,481 cities, committed to 100% renewables, it would have a bigger impact than if the whole U.S. followed through on the Paris Agreement. (As it is, of course, the Trump Administration has pulled us out of that).

Though somewhat aspirational, targets and commitments send a signal, says Appleby. They encourage electric utilities to offer cleaner energy, and prompt businesses and citizens to start switching. Cities can also mandate that municipal buildings use renewables, or pass clean energy mandates on fresh construction. San Francisco has an ordinance saying that 15%-30% of new roof-space has to incorporate solar panels or green roofs.

When mandates don’t work, cities can try stoking demand. Several U.K. towns and cities, including Greater Manchester, have got behind “Big Clean Switch” campaigns that promise households savings on their bills if they commit to clean energy instead of fossil fuels. “Where cities don’t have the power [to make the switch to renewables], they’re working with citizens to increase demand for renewables by getting households to switch to clean tariffs,” Appleby says.