Carbon Majors: Accounting for carbon and methane emissions 1854-2010 Methods & Results Report

Analysis of historic data on fossil fuel extracted by 83 of the world’s largest oil, gas, and coal producing entities and CO2 produced by the 7 largest cement entities provided the basis for estimating emissions of carbon dioxide (CO2) and methane (CH4) attributable to these carbon fuel and cement producers. Annual production data typically reach back to 1920 or earlier for major oil and coal companies, and later for state-­‐owned oil companies in Algeria, Libya, Angola, Nigeria, China, Norway, Brazil, Persian Gulf states, Venezuela, and other chiefly OPEC member countries. Production data for nation-­‐states supplant investor-­‐ owned companies in centralized economies, e.g., Soviet and Polish coal production. The entities include 50 investor-­‐owned and 31 state-­‐owned entities, and 9 current and former nation-­‐states. The amount of carbon extracted is calculated for each entity, by fuel type and year, and emission of CO2 from produced & marketed fuels is estimated after accounting for non-­‐energy uses. Additional direct emissions — chiefly from companies’ own operations, such as venting of CO2 in gas processing, natural gas flaring, use of own fuels, and fugitive methane from coalmines and oil and gas operations — are also estimated. Total emissions of 914 billion tonnes of carbon dioxide equivalent (GtCO2e) are traced to the fuels and cement produced by the 90 Carbon Major Entities (CMEs) based on production data from as early as 1854 to 2010. Emissions include 815 GtCO2 from the combustion of produced & marketed hydrocarbon fuels, 13 GtCO2 from cement production, 6 GtCO2 from natural gas flaring, 5 GtCO2 vented from natural gas, 7 GtCO2 from entities’ own fuel use, and 68 GtCO2e from methane. The Carbon Dioxide Information and Analysis Center (CDIAC) emissions database for fossil fuel CO2, flaring, and cement production from 1751 to 2010 totals 1,323 GtCO2, and 1,450 GtCO2e with methane emissions. This project has quantified emissions equivalent to 63 percent of CDIAC’s global emissions since 1751. Of emissions attributed to CMEs, half have occurred since 1986. Overall uncertainty is ±10 percent. The quality and completeness of production data varies, entities have differing operating characteristics and produce fuels with variable carbon content from differing geologic formations and geographic regions, reporting on methane emissions is often opaque, coalmine depth and rank of produced coals is often not reported, CO2 vented from raw natural gas and variable flaring practices means that uncertainties for individual entities are often higher — typically in the ±10-­‐15 percent range. In aggregate, the sum of all entity emissions is at or below global emissions of both CO2 and methane. Emission factors are based on internationally recognized sources such as the IPCC, World Bank, U.S. EPA, and the European Commission, as well as data from producers, energy engineers, and professional associations.