An airy, brick-walled space, next to a Formula E race track, set the scene for a campaign kickoff Tuesday in Brooklyn, New York, intended to promote zero-emission vehicles (ZEVs) as a way to fight climate change at a time when the federal government wants to relax rules to limit tailpipe emissions.

Organized by The Climate Group and C40 Cities, the initiative highlighted the collective fleet purchasing power of a coalition of large cities including New York, London and Mexico City and multinational businesses including Unilever, EDF Energy and LeasePlan. The idea is to demonstrate to automakers that demand among large fleet buyers for electric vehicles is increasing and to nudge them to roll out more new electric vehicles. (No auto companies officially were represented at the launch. The event was timed to coincide with the Formula E race in Brooklyn.)

"Fleet operators are talking to each other more than ever. We talk about what our manufacturers are doing and what we want from them," said Keith Kerman, New York's chief fleet officer, during the event. The city runs the largest municipal fleet in the United States: 31,000 vehicles include police cars, sanitation trucks and other vehicles. "We are in a great position to push the (auto) industry."

The organizers billed the event as a call for automakers to increase their electric car production to meet demand, despite no new announcements of electric vehicle purchases by any cities or businesses. There was, however, a five-page press release containing quotes from mayors of large cities such as London, Rome, Mexico City and New York about promoting electric car purchases by fleets and consumers between now and 2030. Some officials also called for auto manufacturers to set a timeline for phasing out models that run on fossil fuels.

Going electric will require the effort of the whole village: the policy, the charging infrastructure and the cars.

Car makers sold about 190,000 zero-emission passenger cars and light trucks in 2017 in the United States, or about 1.15 percent of the new cars sold, according to the Alliance for Automotive Manufacturers, which represents 70 percent of the U.S. market for passenger cars and trucks. Sales to government fleets were tiny, accounting for 4.03 percent last year in California, which led the country.

"Automakers are offering more than 50 zero emission vehicle models on sale now, with more on the way. But sales remain low, so we launched a ‘Buyers Wanted’ campaign in April," said Bryan Goodman, director of public affairs at the auto alliance, in an email.

"Automakers have invested substantially in a range of ZEVs and want to sell them in high volumes. State and local governments can help tremendously by buying ZEVs for their fleets and by investing in consumer incentives and charging stations," Goodman added.

Many cities and businesses already have promised to buying more electric or hybrid vehicles, although some plans are more concrete than others. New York, with a fleet of 31,000 vehicles, has pledged that 2,000 of will be all-electric by 2025, a goal that it will meet by next year, Kerman said. Other U.S. cities such as Kansas City, Los Angeles, Pittsburgh, San Francisco and Seattle have been supporting charging network buildouts to rev up demand.

The Climate Group and C40 Cities have been launching campaigns to bring together cities and businesses worldwide to share their plans and lessons about cutting emissions, with the goal of helping countries meet the climate goals set by the 2015 Paris Agreement.

For example, the Climate Group launched EV100 last fall to enroll companies that want to increase their use of electric cars for work or support employees with electric vehicles. It lists 20 members including Unilever, Baidu and Pacific Gas and Electric.

"Going electric will require the effort of the whole village: the policy, the charging infrastructure and the cars," said Michael Lightfoot, chief corporate affairs officer of LeasePlan, during this week’s event.

LeasePlan is a Netherlands-based fleet management company that operates 1.8 million vehicles in 32 countries, including the United States. The company, also part of EV100, plans to achieve net-zero emissions with its fleet by 2030, a goal that could be met by switching to electric or other alternative-energy vehicles, or buying carbon credits.

"It's not just about pointing the finger at automakers," he added.

The Tuesday gathering came at a time when the federal government wants to relax the emissions limits and fuel economy of cars and trucks.

Back in April, the Environmental Protection Agency announced its plan to review and potentially roll back the tough fuel economy standards adopted by the Obama administration. The EPA said the standards are too high and would make new cars more expensive and less affordable for consumers.

The standards require carmakers to produce cars and trucks that will run more efficiently and emit less tailpipe emissions — achieving 54.5 miles per gallon by 2025.

The EPA also threatened to revoke California's ability to set its own fuel economy standards, prompting a counter-threat from California to sue the agency.

Mary Nichols, chairwoman of the California Air Resources Board and a key player in this tussle with the EPA, showed up at the event this week to describe the effort to promote zero-emission vehicles as a "race against time, against the tides and against the buildup of greenhouse gas emissions."

Asked about the latest development in its fight with the Trump administration over fuel economy standards, Nichols said she's waiting to meet with Andrew Wheeler, who became the new EPA administrator only last week, to negotiate a compromise. She hopes to reach an agreement by the end of the year.

"I’m hoping the new administrator will be more open to talk," she said.