Thu October 11, 2012 Software Calculates City-Specific Carbon
Footprint Originally published on Thu October 11, 2012 2:58 pm
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. Many mayors want to
know, too. Hundreds have pledged to reduce their cities'
greenhouse gas emissions, but measurements from satellites and
monitoring stations mostly lump together emissions sources for a
whole city or county. At Arizona State University, Gurney has
come up with a software package that analyzes what he calls a
city's metabolism. "We look at the landscape as if you were in
an airplane, and look down a