In St. Petersburg, Florida, city planners are busy mapping out how the low-lying coastal area will cope with sea level rise. In Salt Lake City, officials are working to get 100 percent of the city's electricity from renewable sources. Out in Los Angeles, electric cars are steadily replacing conventional cars in the city-owned fleet.
These local initiatives and thousands of others were already underway when President Donald Trump took office in January. Today, local leaders say they feel even more compelled to take climate action as Trump vows to cut funding and policies related to energy and environmental protection.
SEE ALSO: This giant offshore wind farm will be the largest in the U.S."We have both an economic opportunity and a responsibility to act -- no matter what President Trump does," said Matt Petersen, the chief sustainability officer of Los Angeles, the second-largest U.S. city.
"That's what we're doing now and intend to do in the future," he added. "And hopefully we'll have some partnership in Washington."
Scott Pruitt, the newly appointed head of the Environmental Protection Agency (EPA), recently said he aimed to be a "good partner" with mayors and local officials.
"Protecting the health of our citizens... is absolutely essential, and we have to do that with a keen interest to jobs and growth as well," Pruitt said at a March 2 meeting with the U.S. Conference of Mayors in Washington.
The former Oklahoma attorney general also vowed to defend certain EPA state grant programs from looming budget cuts, including those for Superfund sites and brownfields, both of which affect cities.
But he didn't mention climate change or clean energy once during the brief meeting -- even though it's EPA's job to regulate greenhouse gas emissions. Pruitt, like Trump, doubts the mainstream scientific conclusion that human activity is driving global warming.
The White House's budget proposal would slice the EPA's overall budget by 25 percent to $6.1 billion and reduce staffing by 20 percent, to 12,400 employees, Washington Post reported.
Meanwhile, on the opposite U.S. coast, Los Angeles is still carrying out its citywide sustainability plan. The city aims to bring $100 million in clean energy investments to the area by fostering startups and attracting developers, and it's seen a rapid rise in rooftop solar projects and electric-car charging stations, Petersen said.
Los Angeles is also a leading member of groups to help officials collaborate on climate policies.
It's among 12 U.S. cities involved in C40, a global network of megacities that work on everything from mass transit networks and microgrids to energy-efficient buildings and climate adaptation. Los Angeles is also studying how it could reach 100 percent renewable energy, a goal that two dozen other cities have already set through a campaign driven by the Sierra Club.
Brendan Shane, C40's regional director for North America, said Trump's election sparked a "rallying cry" among mayors who were gathered at C40's Mexico City summit in late November.
Via Giphy"There was a pretty immediate response that we needed to maintain this whole range of actions that are going to protect people," he said. "The federal government was never going to solve this [climate] problem."
That's not to say cities and states won't be affected by deep budget cuts at the Department of Energy or sweeping policy reversals at the EPA -- two changes Trump is in the process of implementing.
Many local governments have benefited from federal support. The Obama administration provided billions of dollars' worth of grants, tax credits, training and other incentives to make communities cleaner and more resilient to climate change.
While Trump could scrap funding for local climate programs, there's one thing he can't so easily reverse: the low-carbon economy.
Over the last decade, cities and states have steadily lowered their greenhouse gas emissions by making buildings more energy-efficient and supporting the growth of solar arrays, wind farms, zero-emissions vehicles and other clean technologies. States in particular have enacted standards to require utilities to get a specific portion of their supplies from cleaner sources.
Solar and wind prices have plummeted in recent years as technology improves and projects reaches a massive scale. Some major utilities are expanding to include rooftop solar panels and energy-efficiency initiatives, both of which will reduce demand for coal-fired power plants.
Meanwhile, automakers are rolling out more models, at less exorbitant prices, of vehicles that don't run on diesel or petroleum. Consumers are increasingly ditching personal cars in favor of mass transit networks, carpooling services and ride-hailing apps.
These trends will help maintain some of the momentum on climate action at the local level, said Charlie Hales, who until recently was mayor of Portland, Oregon.
"I am bullish on the prospects of cities continuing to get real things done," he said.
Hales noted that Portland has cut its carbon emissions by 21 percent from 1990 levels -- even as its population swelled -- by encouraging residents and companies to use energy-efficient appliances, install rooftop solar systems, plant carbon-absorbing trees and avoid food waste.
As Portland's mayor at the time, Hales was among the more than 70 U.S. mayors who penned a Nov. 22 letter urging then-president-elect Trump to confront the climate crisis head-on.
"While we are prepared to forge ahead even in the absence of federal support, we know that if we stand united on this issue, we can make change that will resonate for generations," the mayors wrote.
In February, U.S. governors mailed their own letter to the White House. A bipartisan group of 20 leaders argued the wind and solar sectors are important economic engines for impoverished rural regions -- the same areas Trump has vowed to revive through coal mining and oil drilling.
Local climate efforts aren't limited to progressive strongholds, like the state of California or the city of Portland. Take Florida, the political battleground state and one of the most vulnerable areas to rising sea levels and acidifying oceans.
Last fall in St. Petersburg, a waterfront city on the Gulf Coast, leaders set aside $1 million for sustainability and resiliency planning. Part of that money will go toward meeting the city's new goal of getting 100 percent of its electricity from clean energy sources.
Ironically, the funding was made possible by the 2010 Deepwater Horizon oil spill. BP agreed to pay the city $6.5 million after the deadly disaster upended the region's fishing and tourism sectors and left beaches covered in goopy crude.
"It was devastating to the economy, devastating to the environment, but even more of a blow to my community," said Emily Gorman, a sustainability consultant from St. Petersburg who worked with the Sierra Club to campaign for the 100-percent target.
"It's a funny silver lining that we now get to take these meaningful steps to make sure these things never happen again," she said, referring to BP's oil spill.
Such initiatives will continue during the Trump presidency, even as the administration tilts policies in favor of fossil fuel producers. Still, cities and states could take even larger steps to fight climate change if the federal government was walking with them, said Hales, the former Portland mayor.
"We will succeed better and faster with the help of national governments," he said.
Additional reporting by Mashable Science Editor Andrew Freedman.