Calculating CARMA: Global Estimation of CO2 Emissions from the Power Sector

This paper provides a detailed description and assessment of CARMA (Carbon Monitoring for Action), a database that reports CO2 emissions from the power sector. We built CARMA to assist the millions of concerned global citizens who can act to reduce carbon emissions once they have timely, accurate information about emissions sources. CARMA also lays the groundwork for the global monitoring system that will be necessary to ensure the credibility of any post-Kyoto carbon emissions limitation agreement. CARMA focuses on the power sector because it is the largest carbon dioxide emitter (26% of the global total), and because power plants are much better-documented than many sources of carbon emissions. The CARMA database and website put anyone with web access a few keystrokes away from detailed knowledge about power plants and the companies that own and operate them. CARMA includes many aggregation tools, so it can be used for local, regional, national and international comparisons. The database also offers complete information about power plants and companies that do not emit carbon because they use non-fossil energy sources (nuclear, hydro, solar, wind, biofuels, geothermal, etc.). In this paper, we provide a description of CARMA’s methodology, an assessment of its strengths and weaknesses, and some tests of its accuracy across countries and at different geographical scales. While CARMA performs well in these tests, we recognize that it is far from perfect. We therefore extend the following invitation to any power plant or company that disputes our estimates: Provide us with better data, verified by an appropriate third party, and we will incorporate them in CARMA.