The suburbs quiet war on CO2

How do you like the suburbs now, city slickers? Our perfect lawns and could-be-anywhere gardens and landscaping are sucking a generous helping of carbon dioxide out of the air.

Today’s mailbag brings this news release from the University of Minnesota which says plants in the suburbs are offsetting fossil fuel emissions in the suburban paradise. Let’s see you do that, my city pals.


Emily Peters, a postdoctoral fellow with the university’s Institute on the Environment and Joe McFadden, an associate professor in the Department of Geography at UC Santa Barbara, published their findings in the current issue of the Journal of Geophysical Research – Biogeosciences.

“Our study is the first to clearly show how much vegetation can change the seasonal pattern of suburban CO2 exchange,” Peters said. “We know cities and suburbs are net emitters of CO2 due to fossil fuel emissions, and vegetation cannot offset this completely. However, our study shows that vegetation is an important player in suburban CO2 exchange, and can even cause the suburban landscape to be a CO2 sink in summer

Placing several sensors high above the ground in a St. Paul suburban neighborhood, Peters and McFadden set out to record tiny changes in CO2, temperature, water vapor and wind. The researchers found that for nine months of the year, the suburban landscape was a net source of CO2 to the atmosphere. During the summer, however, suburban greenery absorbed enough CO2 to balance out fossil fuel emissions within the neighborhood. Peak daily uptake was at the low end of that which would be typical of a hardwood forest in the region.

The CO2-trapping activity of the vegetation differed by type, the study found.

“Lawns’ peak carbon uptake occurred in the spring and fall, because they are made up of cool-season grass species that are stressed by summer heat,” said Peters, “while trees had higher CO2 uptake throughout the summer.” Evergreen trees maintained their CO2 uptake longer than deciduous trees did because they keep their leaves year-round.

The study was funded by NASA and is a first step toward quantifying the role of vegetation in extensive developed areas such as suburbs, which are the parts of urban areas that are growing most rapidly in the country. Potential uses for this type of research include urban planning, where land use and vegetation choices are major decisions, and policy decisions based on reducing greenhouse gases.

In other news, I cut down a spruce tree last weekend. Whoops.

tree_down.jpg

Timing is everything.

  • Robert Moffitt

    The ‘burbs are greener than a lot of people think. A video crew from Motorweek was in Minnesota to film a city that takes a holistic view of reducing greenhouse gases, from their alternative fuel fleet vehicles to their green sports facility.

    Minneapolis? Nope. Brooklyn Park.

  • bsimon

    Glad to hear the burbs are sorta good for something 3 months out of the year… seriously though, keep it up. Maybe we can turn it into a competition & get widespread buy-in to outgreen the urban hipster pseudo-hippies.

  • commenter

    During the summer, however, suburban greenery absorbed enough CO2 to balance out fossil fuel emissions WITHIN THE NEIGHBORHOOD.

    I think this is a key phrase. How many suburbanites commute to jobs within their neighborhoods? I guess the CO2 emitted once you get onto the freeway to head downtown doesn’t count.

  • Bob Collins

    Hey now, city slickers. Neutralize the CO2 produced in YOUR neighborhood and then we’ll talk. :*)

  • Ed

    So for 9 months of the year the suburbs are net CO2 producers. I would like to know what the annual CO2 per capita is in suburbs vs cities. It would also be useful to factor in that most of the cars driven in the cities are probably from suburb dwellers and if people lived where they worked that there would be less CO2 in both the suburbs and cities.

  • JackU

    Obviously then this quote uttered by the late Rodney Dangerfield in Caddyshack needs to be revisited:

    ”I tell ya, golf courses and cemeteries are the biggest wastes of prime real estate”

  • B Joe

    I wonder how much greenery would be required to neutralize the CO2 produced by people from the suburbs driving into the city every day?

  • Xopher

    How many chemicals and fresh water are used on those lawns? How much of those chemicals end up creating other environmental havoc?