New study maps carbon footprints, comes to surprising conclusions


One could lose oneself for hours in the patterns and erratic splotches of colors. Do I live in a swath of self-righteous green? Or in guilt-ridden, fiery orange? Does urban density really reduce our environmental impact? And how gluttonous are those McMansion-dwelling exurbanites, anyway?

The answers to all these questions and more are now just a mouse-click away thanks to an exhaustive household carbon footprint study, complete with those colorful and hypnotic interactive maps, recently published by University of California Berkeley researchers. Drawing on all sorts of data, from the amount of time folks spend in their cars to the number of rooms in their homes to the sources of energy that power their homes, they were able to determine how much greenhouse gases the average household in a particular geographical area is spewing into the atmosphere. The more you consume, the bigger your carbon footprint.

At first glance, the findings aren't so surprising: If you live in a very densely populated urban area — say San Francisco proper or even downtown Los Angeles — your household carbon footprint is likely to be lower than just about anyone else’s. That’s because city-dwellers live in smaller homes, don’t have to travel as far to get to work or run errands, and are more prone to walking or riding public transport than they are to hop in their car and drive. Meanwhile, the California city folk have a relatively low energy-related carbon footprint because California’s electricity mix leans more on hydropower, solar and wind, and less on coal, than other parts of the country.

Yet there is also a bit of a twist. Earlier studies had found a direct, negative correlation between density and carbon footprints — that is, emissions decrease as population density increases. Christopher Jones and Daniel Kammen, the Berkeley researchers, however, “reveal a more nuanced relationship between population density and HCF.” The suburbs just outside those green cities, it turns out, are colored a deep orange on the maps, signifying an unusually large carbon footprint, whether they are densely populated or not. Indeed, the suburban emissions "shadow" tends to blot out the efficiencies of the urban core, making the per capita carbon footprint of big metro areas just as big or bigger than those of smaller, sprawling cities or rural areas.

“As a policy measure to reduce GHG emissions,” Kammen and Jones write, “increasing population density appears to have severe limitations and unexpected trade-offs. In suburbs, we find more population dense suburbs actually have noticeably higher HCF, largely because of income effects.” Yes, income effects: Rich people have bigger carbon footprints, mainly because they live in bigger houses, have more cars and generally consume more of everything.

As one might expect, most of the extra suburban emissions come from transportation. America’s suburbs, especially those in the West, were designed and built with the automobile in mind, making residents prisoners of their cars. Walking or biking from one’s cul-de-sac to work in the urban core can be a harrowing experience, and in some places virtually impossible. Even when progressive metros like Denver expand the public transit web out into the ‘burbs, it’s not always easy to get from home to the bus stop without driving, and if you’re driving to the bus stop, why not just keep going all the way to work?

A cruise around the average-miles-driven map of the Denver area reveals this phenomenon. Folks in downtown Denver drive, on average, around 700 to 800 miles per month, while Denver-fringe suburbanites and exurbanites drive between 2,000 and 3,000 miles per month. The farther they live from the urban core, the farther they drive. Meanwhile, in my hometown of Durango, down in the southwestern corner of the state, commutes are decidedly shorter. Yet we still put 1,800 miles on our cars every month, on average. By my reckoning, 1,500 of those miles are to go skiing or to get to the mountain biking or hiking trailheads.

So what’s the takeaway, aside from the ability of those of us in the green zones to thumb our noses at those who live in the orange and red zones? It’s that dealing with carbon emissions is a complex, place-specific battle. We can’t simply shut down the coal power plants (doing so would have little effect these days on most of California’s carbon footprint); we can’t just use land-use regulations to increase population density; and we can’t just make cars more efficient. We need to do all of the above, and then some. We must figure out how to get suburbanites out of their cars and make their big homes more efficient, along with putting solar panels on the roofs. Urban areas need to get their food from farms that are closer to homes (food makes up a large share of city emissions). Mostly, we need to change the way we, as individuals, behave.

“… 80 percent GHG reductions are possible only with near technical potential efficiencies in transportation, buildings, industry and agriculture,” write Jones and Kammen. “To the extent that these efficiencies aren’t met, highly tailored behavior-based programs must make up the difference.”

Jonathan Thompson is a senior editor at High Country News. He tweets @jonnypeace.

High Country News Classifieds
    Do you want to help shape the future of groundwater in the Grand Canyon region? The Grand Canyon Trust is hiring its first water advocacy...
    California Coalition for Rural Housing (CCRH) seeks a strategic and visionary Executive Director: View all job details here-
    The new novel by Ray Ring, retired HCN senior editor, tackles racism in the wild, a story told by a rural White horsewoman and a...
    Title: Digital Engagement Specialist Location: Salt Lake City Reports to: Communications Director Status, Salary & Benefits: Full-time, Non-Exempt. Salary & Benefits information below. Submission Deadline:...
    Title: Conservation Field Organizer Reports to: Advocacy and Stewardship Director Location: Southwest Colorado Compensation: $45,000 - $50,000 DOE FLSA: Non-Exempt, salaried, termed 24-month Wyss Fellow...
    Who We Are: The Nature Conservancy's mission is to protect the lands and waters upon which all life depends. As a science-based organization, we create...
    Apply by Oct 18. Seeking collaborative, hands-on ED to advance our work building community through fresh produce.
    High Country News is hiring an Indigenous Affairs Editor to help guide the magazine's journalism and produce stories that are important to Indigenous communities and...
    Staff Attorney The role of the Staff Attorney is to bring litigation on behalf of Western Watersheds Project, and at times our allies, in the...
    Northern Michigan University seeks an outstanding leader to serve as its next Assistant Vice President for Diversity and Inclusion. With new NMU President Dr. Brock...
    The Clark Fork Coalition seeks an exceptional leader to serve as its Executive Director. This position provides strategic vision and operational management while leading a...
    Help uphold a groundbreaking legal agreement between a powerful mining corporation and the local communities impacted by the platinum and palladium mine in their backyard....
    The Feather River Land Trust (FRLT) is seeking a strategic and dynamic leader to advance our mission to "conserve the lands and waters of the...
    COLORADO DIRECTOR Western Watersheds Project seeks a Colorado Director to continue and expand WWP's campaign to protect and restore public lands and wildlife in Colorado,...
    Whitman College seeks applicants for a tenure-track position in Indigenous Histories of the North American West, beginning August 2024, at the rank of Assistant Professor....
    Dave and Me, by international racontuer and children's books author Rusty Austin, is a funny, profane and intense collection of short stories, essays, and poems...
    Rural Community Assistance Corporation is looking to hire a CFO. For more more information visit:
    The Absaroka Beartooth Wilderness Foundation (ABWF) seeks a new Executive Director. Founded in 2008, the ABWF is a respected nonprofit whose mission is to support...
    Field seminars for adults in natural and human history of the northern Colorado Plateau, with lodge and base camp options. Small groups, guest experts.
    Popular vacation house, everything furnished. Two bedroom, one bath, large enclosed yards. Dog-friendly. Contact Lee at [email protected] or 520-791-9246.