As some California cities move away from gas in new buildings to address climate change, and after recent news that gas lines in some San Francisco buildings have been encased in concrete during seismic retrofits, we explore the hazardous tradeoffs of burning fossil fuels in buildings. Sasan Saadat, a research and policy analyst with Earthjustice, gives an overview of the pollution created by gas use and explains some of the shortcomings of fossil gas alternatives.