Why Cutting Car and Truck Emissions Is So Hard

State lawmakers and regulators are turning their eyes to the road in the fight against climate change, recognizing that the transportation sector now produces more greenhouse gas emissions than any other portion of the economy.

They are finding few simple solutions.

The Transportation and Climate Initiative released a proposal last month to limit the amount of carbon that fuel suppliers are allowed to emit. The group is made up of 12 Eastern and Mid-Atlantic states plus the District of Columbia, many of which are part of a similar joint effort that has curbed power-sector emissions in the region.

The transportation proposal — which will require states to opt in before it takes effect — is off to a much rockier start, with at least one governor already denouncing it.

California, long the leader in policies to curb transportation emissions, also has had trouble advancing its policies. The state is battling the Trump administration in court over its authority to set stricter auto emission levels than the national standard, which the administration rolled back.

Meanwhile, the California Air Resources Board is considering applying its zero-emission car mandate to trucks, ranging from pickups to tractor-trailers. That would require manufacturers to offer electric truck models in California, while meeting certain sales thresholds, the first such mandate in the United States.

Washington Gov. Jay Inslee, a Democrat who has put climate change at the top of his political agenda, recently unveiled three proposals for reducing transportation emissions in the state. But state officials acknowledge the push will be complicated.

“We by and large know what we need to do in the power sector,” said Reed Schuler, Inslee’s senior policy adviser on climate and sustainability. “The power sector is no one’s idea of simple but compared to the transportation sector it is. … Looking down the road, we know that if we fail to tackle transportation emissions, we will fail to tackle climate change.”

Nationwide carbon emissions from the power sector declined 28% between 2005 and 2017, according to the U.S. Energy Information Administration. The decrease was caused by more energy-efficient buildings and lower demand for electricity, as well as a drop in coal production and an increase in adoption of renewable sources.

But transportation emissions rose slowly from 2012 to 2018, and surpassed the power sector for the first time in 2016. Transportation now makes up 29% of national emissions, the U.S. Environmental Protection Agency found. 

In the power sector, states can get substantial reductions by focusing on a few major regional producers and forcing them to limit their carbon footprint. They’ve done this through clean energy mandates, cap-and-trade programs and investments in renewable energy — aided by market forces that helped drive down emissions further. 

State officials have fewer options on transportation because they need to account for their residents’ current makeup of vehicles, many of which will be on the road for some time, while trying to change driving habits and the types of cars residents will buy. And automakers from out of state and overseas are outside state jurisdiction, unlike regional electric companies.

Most transportation emissions (59%) come from cars and light-duty vehicles, while nearly a quarter come from medium- and heavy-duty trucks, the EPA said. Airplanes, ships, trains and other sources account for 18% of transportation emissions.

A Regional Plan

In the states that make up the Transportation and Climate Initiative, transportation produces 40% of emissions, according to the Center for Climate and Energy Solutions, significantly higher than the national average. Participating states have cut their power sector emissions, leaving transportation emissions as a disproportionate share of the total.

The initiative’s proposal would force fuel companies to purchase allowances for every ton of carbon dioxide their fuel emits, with fewer allowances available each year, in hopes of steadily drawing down emissions. The allowances also would be traded or purchased on a secondary market.

Participating states would reinvest the proceeds, an estimated $6 billion a year, into programs such as boosting public transportation, electrifying state vehicle fleets and offering incentives and charging stations for electric vehicles.

But so far only one governor, Massachusetts Republican Charlie Baker, has pledged to sign on, while most won’t say whether they will join.

Participating states have helped craft the program’s framework, but most of them aren’t likely to commit to it until they see final language this spring on emissions limits and allowance sales. They face pressure from fuel companies who argue the measure would raise gas prices and make it more expensive to transport goods in the region.

New Hampshire had been part of the negotiations, but Gov. Chris Sununu, a Republican, recently announced his state’s withdrawal from the initiative, arguing it will raise gas prices.

If fuel companies passed on all of the costs to consumers, it would raise gas prices no more than 5 to 17 cents a gallon, said Bruce Ho, senior advocate with the Natural Resources Defense Council’s climate and clean energy program. He added that the money reinvested from the allowance revenue is projected to produce far more in terms of wages and job growth than the consumer costs.

“That’s not to say cost conversations are easy,” Ho said. “But it’s not just climate change. It’s improving people’s daily commutes and air quality and creating more equitable economic opportunities by expanding and improving our transportation system.”

The proposal is currently open for public comment, and states are expected to make their opt-in decisions in 2021, whether by legislative approval or administrative rule-making.

On Their Own

Trucks represent about 4% of California’s vehicles, but produce more than 20% of emissions, said Tony Brasil, who heads the Transportation and Clean Technology Branch of the state’s Air Resources Board. But those 1.5 million trucks are owned by hundreds of thousands of different companies.

“When you’re trying to clean up all trucks and potentially affecting all those entities,” Brasil said, “it is a much more difficult action than when you’re regulating a relatively small number of power plants.”

The California plan to mandate zero-emission trucks has drawn the ire of truck manufacturers, who argue the measure would punish dealers by forcing them to purchase more expensive models that aren’t yet as appealing to consumers.

California also limits carbon through its economywide cap-and-trade program, including regulating the fuel suppliers that Northeastern states have targeted. The state in 2018 approved a requirement that all transit agencies switch to zero-emission buses by 2040, and it is crafting rules requiring companies with vehicle fleets to procure zero-emission vehicles. 

In Washington, which has abundant carbon-free hydropower, nearly 45% of carbon emissions come from transportation, according to data from the state Department of Ecology.

Inslee’s primary goal is creating a clean-fuel standard, forcing suppliers to offer more low-carbon fuels over time. California and Oregon already have a clean-fuel standard on the books. By 2028, Inslee said his plan would make transportation fuels 10% cleaner, climbing to 20% by 2035.

“We don’t see any other policy mechanisms on the horizon,” Schuler said, that can take the equivalent of 1 in 5 cars off the road in terms of emissions.

Inslee also is seeking to adopt California’s Zero Emission Vehicle mandate, which 10 other states currently follow.

Inslee wants to force ride-hailing companies like Uber and Lyft to report data on their emissions and submit plans for reducing them. The companies have not weighed in publicly on the measure, but Schuler said he was hopeful they would welcome the chance to “collaborate” with the state to reduce emissions.