A new modeling system called "Hestia" traces greenhouse gases to individual urban buildings and roads.

Carbon emissions are typically tracked at the country or city level, with the focus occasionally narrowed even more onto a county or Census tract. On a global scale that approach provides a pretty helpful window onto problem areas. If metro areas hope to reduce greenhouse gases further, however, they need to zoom in on those precise spots in the city doing the most damage to the environment.

That's the concept behind a new software system called "Hestia," after the Greek goddess of the hearth, capable of tracing carbon emissions down to individual urban buildings and roads. The Hestia project runs numerous public data sources — local air pollution reports, traffic counts, tax assessment information, and the like — through a modeling system that spits out high-resolution, site-specific greenhouse gas maps of a metro area. The system is sophisticated enough to discern fluctuations in each site's emissions on an hourly basis.

As Smithsonian's "Surprising Science" blog reported last week, the research group developing Hestia just released its initial results in a recent issue of the journal Environmental Science & Technology. The researchers, led by Kevin Gurney of Arizona State University, reported their analysis of carbon emissions for the city of Indianapolis. Gurney and company created three-dimensional maps of the city's commercial, residential, and industrial buildings; major and minor roads; and other energy producers from power plants to airports:

The buildings of Indianapolis show some pretty clear emissions patterns. Residential buildings form a satellite of carbon clusters outside the city center along the routes into suburban subdivisions. Commercial emissions form several spokes extended out from a concentrated area in central Indianapolis. Industrial emissions are a bit more scattered but generally follow major transport routes across the metro area. Hourly reports show, predictably, that commercial buildings emit more gases during daytime hours and residences emit more at night.

Major roads are home to most of the city's transportation-related emissions. Though urban interstates and major arterials make up just 15 percent of Indianapolis roadways, they produce 62 percent of its road carbon emissions. Minor arterials, while making up just under 10 percent of road length, produce 22 percent of emissions. Local roads are the most extensive but the least pollutive. Again, as expected, a spike in greenhouse gases occurs during the morning and evening rush hours.

The Hestia system pinpoints the two biggest climate offenders in the metro area as the Harding St. Power Station, a coal-burning plant near the city center, and Indianapolis International Airport. Both are located in Decatur, which is tops among the metro's nine townships in Hestia's emissions rankings for the city. The system also showed a seasonal trend toward greater production in winter — the result of increased heating. Hestia developers released a video of their Indianapolis results along with their paper last week:

The Hestia team is in the process of expanding its analysis to Los Angeles and Phoenix. Gurney and colleagues consider the system "general enough to be applied to any large U.S. city" and hope to create emissions data assessments for every major metro area in the country. Ultimately they believe the tool will help cities target environmental trouble spots and prepare specific, efficient policy responses. They conclude:

High-resolution emissions quantification with functional detail can also aid in the decision making necessary to achieve lowest cost emission mitigation efforts. Knowing the quantities and spatial distribution of fossil fuel CO2 emissions in a city allows for targeting areas with high-impact/low-cost solutions.

Map image via Gurney, K.R. et al., "Quantification of Fossil Fuel CO2 Emissions on the Building/Street Scale for a Large U.S. City," in Environmental Science & Technology, dx.doi.org/10.1021/es3011282; video courtesy of The Hestia Project.

About the Author

Most Popular

  1. Rescue crews and observers on top of the rubble from a collapsed building that fell in the Condesa neighborhood of Mexico City.

    A Brigade of Architects and Engineers Rushed to Assess Earthquake Damage in Mexico City

    La Casa del Arquitecto became the headquarters for highly skilled urbanists looking to help and determine why some buildings suffered more spectacularly than others.

  2. Equity

    What the New Urban Anchors Owe Their Cities

    Corporations like Google and Amazon reap the spoils of winner-take-all urbanism. Here’s how they can also bear greater responsibility.

  3. Amazon's Seattle headquarters is pictured.

    The Ultimate List of Top Contenders for Amazon's HQ2

    We sorted through the longshots and likely contenders so you don’t have to.

  4. Transportation

    Portland Prepares for the Freeway Fight of the Century

    A grass-capped highway expansion in a gentrifying neighborhood? Sounds familiar.

  5. Black and white West Charlotte High School students pose together in and around their school bus in 1972.

    How America's Most Integrated School Segregated Again

    A new book tracks how a Charlotte, North Carolina, high school went from an integration success story to the city’s most isolated and impoverished school.