A growing number of Sonoma County cities are signing on to a national coalition of governments, businesses and educational institutions formed to push back against President Donald Trump’s decision to withdraw the U.S. from an international climate pact.

Santa Rosa on Tuesday night became the latest to join the “We Are Still In” movement, which is led by former New York Mayor Michael Bloomberg and seeks to continue pressing for climate action at home and abroad.

“It seems to me a dereliction of duty when the most prosperous, most powerful nation on Earth turns its back on the international community’s nearly unanimous effort to preserve the planet for future generations,” Santa Rosa Mayor Chris Coursey said at Tuesday’s City Council meeting.

Santa Rosa, Windsor, Petaluma and Sonoma County have signaled support for the Bloomberg coalition, as has the county’s Regional Climate Protection Authority. They join more than 100 cities, hundreds of businesses and universities and a handful of states around the country in backing the initiative.

Bloomberg, the U.N. secretary-general’s special envoy for cities and climate change, wrote in a letter announcing the group’s formation that while the executive branch can speak to its willingness to move forward on climate action, it cannot “determine the pace of progress achieved by U.S. cities, states, the private sector, and civil society. That freedom to lead is part-and-parcel of our federal system.”

Trump argued that the nonbinding Paris agreement, signed by more than 190 countries, was bad for the American economy and business.

But Sonoma County Supervisor Shirlee Zane, the board’s chairwoman, said the president’s decision to withdraw from the agreement “undermined a key pillar of the fight against climate change” — the global campaign to reduce greenhouse gas emissions.

Sonoma County, meanwhile, continues to add to the local initiatives meant to address climate change, Zane noted.

The Sonoma County Water Agency is using renewable sources to generate 100 percent of its electricity, Zane said, and Sonoma Clean Power, the county’s dominant electricity provider, has secured $1 billion in clean energy contracts.

According to climate models, Sonoma County will be whipsawed in coming decades by weather extremes, ranging from increasing temperatures and longer and more frequent droughts, to bigger floods and rising sea levels.

The Sonoma County Regional Climate Protection Authority, formed in 2009 to coordinate countywide climate protection efforts, in 2016 set the bar of reducing greenhouse gas emissions to 25 percent below 1990 levels by 2020 and putting the county on a path to hit 80 percent below those levels by 2050.

That effort remains unchanged in light of Trump’s actions, according to Lauren Casey, director of climate programs for the regional agency.

“State, regional and local governments have a great degree of influence over energy systems, land use, transportation — the primary sources of greenhouse gas emissions,” Casey said.

“That’s where I find hope,” she added.

In a letter supporting the “We Are Still In” movement, Petaluma Mayor David Glass noted a number of steps the city has taken to cut down on greenhouse gas emissions and air pollution, including retrofitting lights, converting to hybrid or zero emission vehicles and using clean burning diesel engines.

The city also is converting by-products from wastewater treatment into compressed natural gas as fuel for city buses and trucks used by a solid waste hauler.

You can reach Staff Writer Derek Moore at 707-521-5336 or derek.moore@pressdemocrat.com. On Twitter @deadlinederek.