In a significant step toward eliminating toxic air pollution, Maryland lawmakers have approved a measure requiring that, year by year, manufacturers ensure that zero-emissions vehicles make up a growing share of the trucks and buses sold in the state. 

Yet some public health advocates fret that the wording of the legislation will allow the state to drag its feet for a year or more if it finds that the infrastructure for electric vehicles is inadequate.

The measure, signed on April 21 by the state’s Democratic governor, Wes Moore, will apply to vehicles from the model year 2027 onward. It requires the Maryland Department of the Environment, the state’s environmental regulator, to adopt regulations by December that  establish sales targets for manufacturers through 2035. 

The law is geared toward adopting California’s Advanced Clean Trucks rule, which serves as a model for states making the transition to emissions-free vehicles. It requires that 15 percent of vehicles ranging from 8,501 to 14,000 pounds in size need to be emissions-free by the 2027 model year. The same would apply to Maryland once it adopts the rule under the new legislation.

Environmental advocates have hailed the legislation as a victory for low-income communities made up primarily of people of color, which have been disproportionately affected by air pollution from highways, freight hubs and ports located next to their neighborhoods. 

The legislation, the Clean Trucks Act of 2023, takes effect on June 1. Yet passage came with a caveat: The bill allows the Maryland Department of the Environment to delay the transition by a year or two if it concludes after a mandatory assessment that the state lacks the infrastructure to make the transition by the model year 2027. That finding must be submitted to the state General Assembly by the end of 2024.

Advocates warn that a delay would deprive communities of the benefits of zero-emission vehicles and set back the state’s emissions reduction goals. Maryland is aiming for a 60 percent reduction in greenhouse gases from 2006 levels by 2031 and net-zero emissions by 2045.

The California rule set sales targets for manufacturers depending on the vehicle’s size, with an interim target of emissions-free vehicles making up 30 to 50 percent of the trucks sold in this category by 2030 and 40 to 75 percent by 2035. The goal is to phase out vehicles that run on dirty diesel and gasoline, which are a major contributor to public health problems in communities near industrial facilities. 

A 2022 study found that 1.8 million excess deaths around the globe in 2019 alone could be linked to urban air pollution. The research showed that 86 percent of adults and children living in cities are exposed to a level of fine particulate matter that exceeds World Health Organization guidelines.

The transportation sector is one of the chief contributors to greenhouse gas emissions in the United States, accounting for 27 percent of the total in 2020, according to the federal Environmental Protection Agency. Aside from warming the planet and causing heat waves, drought, storm surges and floods, the health impact has long been a concern for federal and state agencies. 

The Union of Concerned Scientists has estimated that exposure to harmful particulate matter from vehicle exhaust—specifically, PM2.5 nitrogen oxides, which produce ground-level smog, carbon monoxide, and other hazardous air pollutants—is 12 percent higher for Black Marylanders than that for state residents as a whole. 

Exhaust from diesel trucks is a particularly potent source of PM2.5. The analysis by the Union of Concerned Scientists found that the city of Baltimore had the worst pollution levels, with an exposure rate that was 37 percent higher than the state average, followed by Prince George’s County, with a rate that was 23 percent higher. 

“These two counties are home to more than one-quarter of the state’s population, which means that more than 1.5 million people are affected by this high level of fine particulate matter from cars, trucks and buses,” the study stated.

Sarahia Benn, executive director of the nonprofit Policy Foundation of Maryland, called the legislation “a good start towards addressing environmental injustices across Maryland.” She said that the advocates of the measure would be closely watching the Maryland Department of the Environment and the findings it is due to present to the General Assembly by the end of next year on whether the state will be ready to begin the switch to zero-emissions trucks by the model year 2027.

“We fought hard against that requirement because it was clearly problematic,” Benn said. She added that she felt somewhat encouraged when Moore committed financial resources to ensuring that the state expands its network of charging stations and other infrastructure before the model year 2027 kicks in. “We cannot afford any delay, and the advocate community will not let the MDE drop the ball on this,” she said. 

The truck industry, meanwhile, has objected to the 2027 timeline set by the legislation. “We’re not opposed to electric trucks,” said Louis Campion, president and chief executive of the Maryland Motor Truck Association. “We have concerns about some of the impractical and unrealistic timelines that fail to recognize many hurdles that have to be overcome before widespread adoption of electric trucks can happen.” 

He said that industry leaders had urged lawmakers to take a more measured approach that factors in obstacles to the transition to zero-emissions vehicles.

Campion praised the caveats inserted in the bill. “The legislators felt it was reasonable to include language that required a needs assessment prior to implementation that looked at whether the state fleet can convert to electric and what those costs will be, impacts on grid Infrastructure, charging stations, because we want to move toward electric trucks in a practical and successful way,” he said.

But advocates point out that the Maryland Department of the Environment already has the statutory authority to put a pause on any project it finds to be unfeasible. The addition of the “needs assessment” requirement, they argue, weakens the measure by making it contingent upon the Department of the Environment’s nod.

Rep. Sara Love of Montgomery County, a sponsor of the legislation, said that the assessment would size up the needs for an expanded charging infrastructure, grid capabilities and anything else needed to smooth the transition to zero-emission medium and heavy-duty trucks. 

“It is pretty common in Maryland to include a pause button in legislation,” she said. The Maryland Department of the Environment “can push it off a model year or two” if “conditions are not satisfactory.” 

Love also pointed to a grant program in the bill that would help people to afford emissions-free medium and heavy-duty electric trucks, which are more expensive at this point than the polluting alternative. A study released last year by the U.S. Department of Energy’s National Renewable Energy Laboratory estimated that electric trucks will cost the same as diesel trucks or less by 2035.

“From my conversations with both the industry and environmentalists, everybody is really excited about this,” Love said. “We just want to make sure that we have the infrastructure and the grid capability in order to effectively implement it.”

Jillian Blanchard, director of the climate change program at Lawyers for Good Government, a national nonprofit, said the Maryland bill was clearly not a rubber stamp of California’s Advanced Clean Trucks rule.

She said the California bill did not allow for a delay in implementation because the state had already conducted a needs assessment and knew that the transition was viable. “The Maryland law brings the needs assessment into the law itself, which allows for delayed implementation as a result,” she said. 

Still, “it’s a really big step,” Blanchard said. “It’s important to start making the commitment, and the commitment is made. They can delay it by one or more model years, but it will have to be implemented ultimately.” 

Once it adopts the rule, Maryland will join eight other states that have embraced it: California, Colorado, Oregon, Washington, New Jersey, Massachusetts, New York, and Vermont. North Carolina is taking steps to adopt the rule as well.