Power generation accounts for about one-quarter of global carbon emissions, a major cause of global warming. CARMA (Carbon Monitoring for Action) was created to inventory and monitor this massive output to “equip individuals with the information they need to forge a cleaner, low-carbon future.” There are over 50,000 power plants and 4,000 power companies worldwide available on CARMA’s database, which is produced and financed by the Confronting Climate Change Initiative at the Center for Global Development. CARMA can be used by consumers, investors, shareholders, and policymakers to name a few for influencing decisions on power generation.

For power plants within the U.S., CARMA uses E.P.A. data. For non-reporting plants, CARMA estimates emissions using a statistical model that utilizes detailed data on plant-level engineering and fuel specifications. The database is updated quarterly to reflect changes in ownership, construction, renovation, planned expansions, and plant retirements. The plants can generate power from any number of sources, including hydroelectric, fossil fuels, and nuclear. According to the site, “CARMA does not endorse or favor any particular technology. Our goal is to simply report the best available information on sources of power sector carbon emissions.” In many cases data can be downloaded from the site.