Suburban residents' climate-warming emissions are higher than city dwellers', mainly because of higher energy use in homes and transportation—so those are the first places to look for savings.

Suburban sprawl, with its single-family homes and car-centric culture, is sometimes criticized as an example of the overconsumption that helps fuel climate change. And it's true that, at least in high-income countries, people in semi-urban and suburban areas emit more climate-warming carbon dioxide (CO2) than those in cities (1).

But for those who prefer to live in the suburbs, there are still plenty of opportunities to lower their greenhouse gas emissions. And as cities have become increasingly expensive, more Americans have found urban life inaccessible—particularly low-income people and people of color (2)—making it even more important to lower the climate impact of suburban life.

In terms of CO2 emissions, the biggest difference between urban and suburban areas is their drastically different uses of space, inside and outside the home. “Single-family homes are really kind of what we think of as the American typical home, but they’re probably the most inefficient way to build housing in terms of energy,” says David Hsu, MIT associate professor of urban and environmental planning.

But local policymakers have some power to change that. Building and zoning codes, which govern the size and specifications of new buildings, are often decided locally. And many localities are getting creative about overhauling how homes are designed. In 2020, updates to California’s building code required that all new homes include solar panels (3). New York recently passed a state budget that outlaws the installation of CO2-emitting gas stoves and furnaces in many new buildings (4). And Oregon allowed the construction of more efficient multi-family buildings in areas where single-family homes have dominated (5).

Even if you live in a place without such policies, certain changes can make your home less carbon-intensive. More than 70 percent of home energy use comes from water heating and home heating and cooling (6). Technologies like heat pumps, which use electricity to transfer heat, can replace carbon-emitting oil or gas heat, and good insulation can keep homes comfortable with less heating and air conditioning. The 2022 Inflation Reduction Act (IRA) included rebates and credits for certain home energy efficiency and electrification technologies (7), so it’s worth checking if you qualify, and some states also have programs that help fund home weatherization.

Differences in transportation also help create the gulf in emissions between cities and suburbs. While many cities are designed at least partly around public transit, suburbs were built around cars. A private, gas-powered car emits far more CO2 per passenger-mile than a bus or train (8)—but switching to an electric car can significantly lower the emissions associated with personal car trips (9). (The IRA includes some credits for electric vehicles, too, depending on your income and which one you buy.)

Hsu also recommends electric bikes, sales of which, he says, are actually rising faster than those of electric cars. Of course, the climate impact of electric cars and bikes depends in part on the power mix of the grid that provides the electricity to charge them. But as states increasingly add clean energy to their grids, these transportation options will become even cleaner. Many suburbs also have some form of public transit, so individuals can scope out whether any trips could happen on a bus, train, or even on foot.

Ultimately, suburban life is more carbon-intensive because of design choices, and those choices aren’t all set in stone. “Citizens can help push policymakers or educate policymakers,” says Hsu. “You can get involved in local politics, you can talk to your state representative about why climate change is important.”

“Finally, I encourage people to vote for people who have legitimate plans for climate change,” he adds.

Thank you to Joseph Liu of California for the question. You can submit your own question to Ask MIT Climate here.

Published June 5, 2023.

FOOTNOTES

1 Jones, Christopher and Daniel M. Kammen. "Spatial distribution of U.S. household carbon footprints reveals suburbanization undermines greenhouse gas benefits of urban population density," Environmental Science and Technology, Vol. 48, No. 2, 2014, doi:10.1021/es4034364. See also, Muñoz, Pablo, Sabrina Zwick and Alisher Merzabaev, "The impact of urbanization on Austria's carbon footprint," Journal of Cleaner Production, Vol. 263, No. 1, August 2020, doi:10.1016/j.jclepro.2020.121326; and Goldstein, Benjamin, Dimitrios Gounaridis and Joshua P. Newell, "The carbon footprint of household energy use in the United States," Proceedings of the National Academy of Sciences, Vol. 117, No. 32, July 2020, doi:10.1073/pnas.1922205117.

2 National Equity Atlas: The Shrinking Geography of Opportunity in Metro America. Thai Le, Edward Muña, Sarah Treuhaft, and Rasheedah Phillips, May 10, 2022.

3 California Energy Commission: Building Energy Efficiency Standards - Title 24.

4 CNN: New York becomes the first state to ban natural gas stoves and furnaces in most new buildings. Rachel Ramirez and Ella Nilsen, May 3, 2023.

5 Oregon Public Broadcasting: Oregon strikes exclusive single-family zoning, but effects may take years. Jeff Mapes, July 3, 2019.

6 U.S. Department of Energy Office of Energy Efficiency & Renewable Energy: Why Energy Efficiency Upgrades. Accessed June 5, 2023.

7 White House: cleanenergy.gov.

8 International Energy Agency: GHG intensity of passenger transit modes, 2019. Updated October 26, 2022.

9 Ask MIT Climate: Are electric vehicles definitely better for the climate than gas-powered cars? October 13, 2022.