EARTHTRENDS DATA TABLES TECHNICAL NOTES: Climate and Atmosphere For more information, please consult http://earthtrends.wri.org DEFINITIONS AND METHODOLOGY Total Carbon Dioxide (CO2) Emissions measures the mass of carbon dioxide produced during combustion of solid, liquid, and gaseous fuels, as well as from gas flaring and the manufacture of cement. Data are expressed in million metric tons. CO2 emissions from land- use change are not included here. These estimates do not include bunker fuels used in international transportation. Where values were originally in given in mass of carbon, WRI multiplied by 3.664 (the ratio of the molecular mass of CO2 to that of carbon) to convert to mass of CO2. CO2 Emissions Per Capita measures the mass of CO2 produced per person for a country or region, in metric tons. WRI calculates per capita emissions with population estimates from the United Nations Population Division (2002 revision). Data on carbon dioxide emissions are obtained from the World Resources Institute's Climate Analysis and Indicators Tool (CAIT). In order to provide the most complete and accurate data set, CAIT compiles data from the International Energy Agency (IEA), the Carbon Dioxide Information Analysis Center (CDIAC), and the Energy Information Agency (EIA). Fossil fuel emissions estimates for 131 countries are available from the IEA and reported in CAIT. WRI used CDIAC data on fossil fuel emissions for the 53 countries that lack IEA data. (Data for Lesotho were obtained from the EIA.) Data on emissions from cement manufacturing were obtained from CDIAC for all countries and added to the fossil-fuel emissions totals by WRI. A complete country-by-country listing of source and notes can be found at http://cait.wri.org/cait.php?page=notes&chapt=2. Emissions are calculated by the IEA using the Intergovernmental Panel on Climate Change (IPCC) Reference Approach. CDIAC estimates are derived from energy statistics obtained from United Nations Statistical Office questionnaires and supplemented by official national statistical publications. The U.S. Energy Information Administration (EIA) estimates CO2 emissions by country and year, based on energy balances. Cumulative CO2 Emissions from Fossil Fuels and Cement, 1950-2000 represents the total mass of CO2 produced in all years from 1950 to 2000 as a result of the combustion of solid, liquid, and gaseous fuels, as well as from gas flaring and the manufacture of cement. CO2 emissions from land use change are not included here. These estimates do not include bunker fuels used in international transportation. To estimate cumulative emissions in recently formed countries, WRI apportions emissions estimates based on current emissions and historical emissions from former countries and territories. Cumulative CO2 Emissions from Land-Use Change, 1950-2000 represents the total mass of carbon dioxide (CO2) absorbed or emitted into the atmosphere between 1950 and 2000 as a result of man-made land-use changes (for example, deforestation, shifting cultivation, and vegetation re-growth on abandoned croplands and pastures). Positive values signify a positive net flux ("source") of CO2, indicating that carbon dioxide has been released into the atmosphere. Negative values signify a negative net flux ("sink") of CO2, indicating that carbon dioxide has been absorbed as a result of the re-growth of previously removed vegetation. Data include emissions from living and dead vegetation disturbed at the time of clearing or harvest, emissions from wood products (including fuel wood), and emissions from the oxidation organic matter in the soil in years following initial cultivation. Ecosystems that are not directly affected by human activities such as agriculture and forestry are not included in these totals. The net flux of CO2 for each country was calculated by R.A. Houghton at the Woods Hole Research Center based on regional fluxes. WRI calculated cumulative carbon emissions from land use change using annual country-level data. For more information, refer to "Data Note: Emissions (and Sinks) of Carbon from Land-Use Change," online at http://cait.wri.org. Carbon Dioxide Emissions by Sector shows the proportion of total CO2 emissions from fossil- fuel burning contributed by transportation, industry, and electricity production. The Transportation sector includes fossil fuel emissions from road, rail, air, and other forms of transportation, and agricultural vehicles while they are on highways. Data do not include international aviation or ship emissions. The Industry and Construction sectors include fossil- fuel emissions in all industries and construction. The Electricity sector includes fossil-fuel emissions from public electricity generation, combined heat and power generation, and heat plants. Emissions from electricity and heat production for use by the producer (autoproduction) for public or private activities are included here. The emissions figures presented here are calculated by the IEA using the IPCC Sectoral Approach and default emission factors from the Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories and the IEA energy balances. Methane Emissions measures the total release of methane (CH4) into the earth's atmosphere that results from human activities such as agricultural and industrial methane production. Values are expressed in thousand metric tons of CO2 equivalent using the global warming potential (GWP), which allows the different gases to be compared on the basis of their effective contributions. One kilogram of methane is 23 times as effective at trapping heat in the earth's atmosphere as a single kilogram of CO2 (using a time horizon of 100 years). Nitrous Oxide, Total Emissions represents the total release of nitrous oxide (N2O) into the earth's atmosphere that results from human activities such as agriculture, biomass burning, industrial activities, and livestock management. Values are expressed in thousand metric tons of CO2 equivalent using the GWP, which allows the different gases to be compared on the basis of their effective contributions. The global warming potential of one kilogram of N20 is nearly 300 times that of a single kilogram of CO2 (using a time horizon of 100 years). Fluorinated Gases, Total Emissions represents the total release of hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6) into the earth's atmosphere. These three groups of fluorinated gases ("f-gases") persist in the atmosphere for thousands of years. Hydrofluorocarbons are a by-product of HFC-23 and HCFC-22 (IPCC Source Categories 2E and 2F), which are used in the production of aerosols, refrigeration/AC compounds, solvents, foams, fire extinguishing compounds, semiconductors, and flat-panel displays. Perfluorocarbons are produced in the manufacture of semiconductors and as a byproduct of CF4 and C2F6 in primary aluminum production (IPCC Source Categories 2C, 2E, and 2F). Sulfur Hexafluoride emissions are generated from magnesium processing, semiconductor production, and the use and manufacture of gas insulated switchgear in electricity distribution networks (IPCC Source Categories 2C and 2F). Values are expressed in thousand metric tons of CO2 equivalent using the global warming potential (GWP), which allows the different gases to be compared on the basis of their effective contributions. The global warming potential of one kilogram of a fluorinated gas is several thousand times that of a single kilogram of CO2 (using a time horizon of 100 years). Most of the Methane, Nitrous Oxide, and Fluorinated Gas data shown here were compiled by WRI from Non-CO2 Gases Economic Analysis and Inventory. This data set was prepared by the U.S. Environmental Protection Agency (EPA), covers 90 countries, and accounts for close to 90 percent of global emissions. The remaining data were either obtained from the EDGAR database of the Dutch National Institute of Public Health and the Environment (RIVM) or estimated by WRI based on regional totals and figures for earlier years. A complete listing of sources by country is available at http://cait.wri.org/cait.php?page=notes&chapt=2 Total GHG Emissions include the total mass of carbon dioxide (CO2) emitted from fossil fuel and cement manufacturing plus the CO2 emissions equivalent of methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6) in the year 2000. Data shown here exclude CO2 from land-use change. Kyoto Protocol Status indicates the year that a country ratified the Kyoto Protocol to the United Nations Framework Convention on Climate Change (UNFCCC). Ratification (or its equivalents of acceptance, approval, or accession) binds the state to observe the treaty. The Kyoto Protocol was established in 1997 by the third session of the Conference of Parties (COP-3) to the UNFCCC. Upon ratification, Annex I (industrialized) countries commit themselves to reducing their collective emissions of six greenhouse gases by at least 5 percent from 1990 levels during the first commitment period, which is 2008-2012. Compared to emissions levels that would be expected by 2010 without emissions-control measures, the Protocol target represents a 30 percent cut. Under the Protocol, both developed and developing countries agree to limit emissions and promote adaptation to future climate change, submit information on their national climate-change program and inventories, promote technology transfer, cooperate on scientific and public research, and promote public awareness and education. The Protocol came into force on February 16, 2005, following ratification by Russia in November, 2004. More information is available in A Guide to the Climate Change Convention Process, online at http://unfccc.int/resource/process/guideprocess-p.pdf. FREQUENCY OF UPDATE BY DATA PROVIDERS Carbon dioxide emissions, cumulative emissions, and non-CO2 greenhouse gas emissions are updated by WRI's CAIT tool when new data are available; most CO2 emissions data are updated annually, while non-CO2 GHG emissions are updated intermittently by RIVM and the EPA. Sectoral emissions data are updated by the IEA every year; as of spring, 2005, data are available from the original source through 2002. Sectoral emissions data from 2000 are included here to enable direct comparisons with the emissions data in this table. DATA RELIABILITY AND CAUTIONARY NOTES CO2 Emissions: The IPCC Reference Approach (used here for most emissions estimates) can overestimate emissions because it uses energy supply data rather than combustion data. In a few cases, the estimates shown here differ significantly (by more than 5 percent) from those reported by individual countries or by the UNFCCC. This is because some countries use different energy figures than the IEA and WRI or treat bunker fuels differently. Other countries calculate emissions with specific calorific values instead of the averages used by the IEA. Emissions data are synthesized by WRI from three different data sets, which presents both advantages and disadvantages. On the one hand, "filling" the gaps from different data sources improved the ability to make cross-country comparisons and related analyses. Yet comparability can be endangered when data points from different sources (using different methodologies) are placed side-by-side. For a complete discussion of CAIT's methodology, see http://cait.wri.org/downloads/cait_ghgs.pdf. Cumulative CO2 Emissions from Land-Use Change: CO2 emissions estimates from land-use change are considerably less reliable than other CO2 and GHG emissions estimates; as a result, data should be treated as order-of-magnitude estimates. The data provider states that yearly flux estimates are uncertain on the order of ±150 percent for large fluxes, and ±50 million tons of carbon per year for estimates near zero. The cumulative emissions presented here, however, are more accurate than the data for individual years. More information is available at: http://cait.wri.org/downloads/DN-LUCF.pdf. CO2 Emissions by Sector: Data shown in these columns is calculated using the IPCC Sectoral Approach, which surveys actual consumption of fossil fuels by each sector in order to calculate emissions. Other columns in the table have been calculated using the IPCC Reference Approach. While in theory the numbers should be identical, in practice there are minor variations between the data produced by the two methodologies. Methane, Nitrous Oxide, and Fluorinated Gases: Generally, estimates of non-CO2 GHG emissions are less certain than CO2 emissions estimates. Estimates of nitrous oxide emissions are less certain than methane and fluorinated gas estimates. This data set provides a sound basis for comparability, however, since the methods used are comparable to IPCC methodologies, the global totals comply with budgets used in atmospheric studies, and the data were based on international information sources, The data presented here may not match the official methane emissions estimates submitted by countries to the UNFCCC. In most cases, however, the differences are not substantial. In the year 2000, WRI estimated methane and nitrous oxide emissions for some countries (accounting for about 10 percent of all emissions); these estimates should be considered rough approximations. SOURCES Emissions—Total, Per Capita, Cumulative, Methane, Nitrous Oxide, Fluorinated Gases: World Resources Institute. 2005. Climate Analysis Indicators Tool (CAIT), version 2.0. World Resources Institute, Washington D.C. Online at http://cait.wri.org. CO2 Emissions by Sector: International Energy Agency (IEA). 2003. CO2 Emissions from Fossil Fuel Combustion (2003 Edition). Paris: Organization for Economic Cooperation and Development (OECD). Database online at http://data.iea.org/ieastore/default.asp. Kyoto Protocol, Year Ratified: United Nations Framework Convention on Climate Change(UNFCCC). 2005. Kyoto Protocol Status of Ratification. Bonn: UNFCCC. Online at http://unfccc.int/files/essential_background/kyoto_protocol/application/pdf/kpstats.pdf