Read how scientists at Arizona State University developed a computer simulation, Hestia, that displays a city’s greenhouse-gas emissions in detail, showing how much heat-trapping carbon dioxide individual buildings and highways generate. By concentrating on areas with the most greenhouse gas emissions, a city could make significant improvements in its overall emissions picture with relative ease.

Arizona State already has already created a simulation, Vulcan, which estimates and maps major CO2 sources in the U.S. down to the county level, including major power plants, highways and big, concentrated sources of emissions from the burning of coal, oil and gas. The Hestia project relies on Vulcan’s county-level information, but draws on all sorts of finer-scale data to pinpoint exactly where emissions are coming from.