Software Calculates City-Specific Carbon Footprint

One way to measure greenhouse gases is simply to capture them at the source: You put an instrument on a smokestack, for example. Cities, however, are full of cars, buses, factories and homes that all use fuel or electricity. No one really knows how much carbon dioxide, the main greenhouse gas, comes from each.

Ecologist Kevin Gurney says he can find out.

“If a molecule of CO2 is coming from the surface due to the combustion of fossil fuel, I want to know about it,” he says.