A new software system can estimate greenhouse gas emissions across urban landscapes all the way down to roads and individual buildings, U.S. scientists say. Until now scientists could only quantify carbon dioxide emissions at a much broader level, researchers at Arizona State University said in announcing their new system. The system, dubbed \"Hestia\" after the Greek goddess of the hearth and home, combines extensive public database \"data-mining\" with traffic simulation and building-by-building energy-consumption modeling to create high-resolution maps clearly identifying CO2 emission sources in a way policy-makers can utilize and the public can understand, they said. \"Cities have had little information with which to guide reductions in greenhouse gas emissions -- and you can\'t reduce what you can\'t measure,\" ASU life science Professor Kevin Gurney said. \"With Hestia, we can provide cities with a complete, three-dimensional picture of where, when and how carbon dioxide emissions are occurring.\" The researchers said they hope to ultimately map the CO2 emissions in all major cities across the United States, which accounts for nearly one-quarter of all global CO2 emissions. Such detailed emissions information can help determine what society can do locally and globally about climate change, they said.