Transportation is the largest source of planet-warming greenhouse gases in the United States today and the bulk of those emissions come from driving in our cities and suburbs. The map below shows a year’s worth of CO 2 from passenger and freight traffic on every road in the Akron, Ohio, metro area Albany, N.Y., metro area Albuquerque metro area Allentown, Pa., metro area Asheville, N.C., metro area Atlanta metro area Augusta, Ga., metro area Austin, Texas, metro area Bakersfield, Calif., metro area Baltimore metro area Baton Rouge, La., metro area Beaumont, Texas, metro area Birmingham, Ala., metro area Boise, Idaho, metro area Boston metro area Bridgeport-Stamford, Conn., metro area Buffalo metro area Cape Coral-Fort Myers, Fla., metro area Charleston, S.C., metro area Charlotte, N.C., metro area Chattanooga, Tenn., metro area Chicago metro area Cincinnati metro area Cleveland metro area Colorado Springs metro area Columbia, S.C., metro area Columbus, Ohio, metro area Corpus Christi, Texas, metro area Dallas-Fort Worth metro area Dayton, Ohio, metro area Denver metro area Des Moines metro area Detroit metro area Durham-Chapel Hill, N.C., metro area El Paso metro area Fresno, Calif., metro area Grand Rapids, Mich., metro area Greensboro, N.C., metro area Greenville, S.C., metro area Gulfport-Biloxi, Miss., metro area Harrisburg, Pa., metro area Hartford, Conn., metro area Houston metro area Indianapolis metro area Jackson, Miss., metro area Jacksonville, Fla., metro area Kansas City, Mo.-Kansas City, Kan., metro area Knoxville, Tenn., metro area Las Vegas metro area Lexington, Ky., metro area Little Rock, Ark., metro area Los Angeles metro area Louisville, Ky., metro area Madison, Wis., metro area McAllen, Texas, metro area Memphis metro area Miami metro area Milwaukee metro area Minneapolis-St. Paul metro area Nashville metro area New Haven, Conn., metro area New Orleans metro area New York metro area Ogden, Utah, metro area Oklahoma City metro area Omaha metro area Orlando, Fla., metro area Oxnard-Thousand Oaks, Calif., metro area Philadelphia metro area Phoenix metro area Pittsburgh metro area Portland, Maine, metro area Portland, Ore., metro area Providence, R.I., metro area Raleigh, N.C., metro area Richmond, Va., metro area Riverside-San Bernardino, Calif., metro area Rochester, N.Y., metro area Sacramento metro area Salt Lake City metro area San Antonio metro area San Diego metro area San Francisco metro area San Jose, Calif., metro area Sarasota-Bradenton, Fla., metro area Scranton, Pa., metro area Seattle metro area Shreveport, La., metro area St. Louis metro area Stockton, Calif., metro area Syracuse, N.Y., metro area Tampa, Fla., metro area Toledo, Ohio, metro area Tucson, Ariz., metro area Tulsa, Okla., metro area Virginia Beach-Norfolk, Va., metro area Washington metro area Wichita, Kan., metro area Winston-Salem, N.C., metro area Worcester, Mass., metro area or choose another metro area. Lower emissions Higher emissions These findings come from a New York Times analysis of new data released through Boston University’s Database of Road Transportation Emissions. The database provides the most detailed estimates available of local on-road CO 2 over the past three decades. The map above shows emissions in 2017.

Even as the United States has reduced carbon dioxide emissions from its electric grid, largely by switching from coal power to less-polluting natural gas, emissions from transportation have remained stubbornly high.

The bulk of those emissions, nearly 60 percent, come from the country’s 250 million passenger cars, S.U.V.s and pickup trucks, according to the Environmental Protection Agency. Freight trucks contribute an additional 23 percent.

In 2017, transportation was the top source of greenhouse gases. The vast majority of those emissions came from driving. 2.5 billion metric tons 2.5 billion Electricity Trains, planes, ships and other 2.0 2.0 transportation Trucks Industry 1.0 Agriculture Passenger vehicles 0.5 2017 1990 1990 2017 In 2017, transportation was the top source of greenhouse gases. The vast majority of those emissions came from driving. 2.5 billion metric tons 2.5 billion Trains, planes, ships and other Electricity 2.0 2.0 transportation Trucks Industry 1.0 Agriculture Passenger vehicles 0.5 2017 1990 1990 2017 In 2017, transportation was the top source of greenhouse gases. The vast majority of those emissions came from driving. 2.5 billion metric tons 2.5 billion Trains, planes, ships and other Electricity 2.0 2.0 transportation Trucks Industry 1.0 Agriculture Passenger vehicles 0.5 2017 1990 1990 2017 In 2017, transportation was the top source of greenhouse gases. The vast majority of those emissions came from driving. 2.5 billion metric tons 2.5 billion Electricity Trains, planes, ships and other 2.0 2.0 transportation Trucks Industry 1.0 Agriculture Passenger vehicles 0.5 2017 1990 1990 2017 Charts show the carbon dioxide equivalent of greenhouse gas emissions. · Source: Environmental Protection Agency

Reducing emissions from driving has been a big challenge, said Conor Gately, who led the project mapping CO 2 on America’s roads as a postdoctoral researcher at Boston University. Emissions dipped during the recession of the late 2000s, but have been ticking back up since 2013.

National fuel economy standards put in place under the Obama administration have helped temper the rise in automotive emissions because the rules require cars and trucks to use less gasoline per mile traveled. But even as vehicles have become more efficient, Americans, buoyed by a strong economy and low gas prices, have been driving more miles and buying more S.U.V.s and pickup trucks, which have lower gas mileage. Freight trucking is also on the rise.

The Trump administration is expected to finalize a rollback of efficiency standards for passenger vehicles this month, a move that could significantly increase future emissions from America’s cars and trucks.

Emissions From Driving Have Grown Fastest in America’s Cities and Suburbs

Boston University’s emissions database, first published in 2015 and updated this month with an additional five years of data, reveals that much of the increase in driving-related CO 2 has occurred in and around cities.

Suburban driving, including commuting, has been a major contributor to the expanding carbon footprint of urban areas, Dr. Gately said.

But, he added, “even in the densest cities, the vast majority of trips still happen in a motor vehicle.” These trips include work commutes, school drop-offs and millions of other daily errands, as well as freight deliveries and other business traffic, all of which contribute to planetary warming.

The New York Times identified the 100 metropolitan areas with the highest total emissions from driving, based on Boston University’s local estimates:









In nearly every metro area, total emissions have increased since 1990. Here’s the trend line for the area you selected in the top map. The New York area, home to 20 million Americans, accounted for the largest share of driving-related CO 2 . After years of increase, emissions ebbed during the late-2000s recession but rebounded by 2017. In more car-dependent areas, like Dallas-Fort Worth, emissions from driving barely dipped during the recession and have increased rapidly in recent years. But, adjusted for population, these cities flip: Residents in the denser, more transit-friendly New York area contribute far less CO 2 from driving on average than their counterparts in Dallas. Per capita emissions have also ticked up in most metro areas in recent years. Here’s the per person trend for your selected area.

Meaningfully lowering emissions from driving requires both technological and behavioral change, said Deb Niemeier, a professor of civil and environmental engineering at the University of Maryland. Fundamentally, you need to make vehicles pollute less, make people drive less, or both, she said.

Cities and states have sought to green the vehicles on their roads by providing tax incentives for electric and hybrid models, and by building more charging stations. California has the unique authority to set its own pollution standards for cars and trucks that are stricter than national rules, but the Trump administration is challenging this power.

Cities have also tried to reduce the amount people drive by encouraging carpooling, expanding transit options — including subways, light rail and rapid bus services — and planning denser, more accessible neighborhoods, too. In 2021, New York will become the first city in America to charge drivers a fee for entering highly congested areas.

In the absence of federal leadership, such local and regional initiatives have taken on new urgency.

“Every city has some workable strategies to lower vehicle-related greenhouse gas emissions,” Dr. Niemeier said, but the right mix depends on local conditions, including existing development patterns and infrastructure. “What works in New York City will not work in Dallas-Fort Worth,” she said.

No matter the mechanism, Dr. Gately of Boston University said, “Big, long-term change needs to happen in America’s cities.”

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