&ER& United States Environmental Protection Agency The U.S. Greenhouse Gas Inventory ------- nternational Reporting In 1992, under the United Nations Framework Convention on Climate Change (UNFCCC), the United States, along with 185 other countries, agreed to develop and submit a national inventory of anthropogenic greenhouse gas emissions and sinks. To fulfill this obligation, each year the U.S. Environmental Protection Agency (EPA) prepares the official Inventory of U.S. Greenhouse Gas Emissions and Sinks in cooperation with the U.S. Department of State and other U.S. government agencies. Under the direction of the Intergovernmental Panel on Climate Change (IPCC), hundreds of scientists and national experts collaborated in developing a set of methodologies and guidelines to help countries create inventories that are compa- rable across international borders. The information presented in the Inventory of U.S. Greenhouse Gas Emissions and Sinks is in full compliance with these IPCC guidelines. he U.S. Greenhouse Gas Inventory Program The U.S. Environmental Protection Agency's Clean Air Markets Division (CAMD) in the Office of Atmospheric Programs is responsible for developing the annual Inventory of U.S. Greenhouse Gas Emissions and Sinks. EPA's Greenhouse Gas Inventory Program has developed extensive technical expertise, internationally recognized analytical methodologies, and one of the most rigorous manage- ment systems in the world for the estimation, documentation, and evaluation of greenhouse gas emissions and sinks for all source categories. To accomplish its work, the Inventory Program collaborates with hundreds of experts representing more than a dozen federal agencies, many academic institutions, industry associations, consultants, and environmental organizations. The Program also works directly with industries and other government agencies to develop high quality emissions data and is supported by CAMD's experience with the U.S. emissions trading programs and its network of continuous emission monitors for C02 on most electric power plants in the United States. hat is the Significance of Emission Inventories? Greenhouse gas emission inventories are developed for a variety of reasons. Scientists use inventories of natural and anthropogenic emissions as tools when developing atmospheric models. Policy makers use inventories to develop strategies and policies for emissions reductions and to track the progress of those policies. And, regulatory agencies and corporations rely on inventories to establish compliance records with allowable emission rates. Businesses, the public, and other interest groups use inven- tories to better understand the sources and trends in emissions. A well constructed inventory is consistently prepared, accurate, and thoroughly documented. Inventories typically include the following information: Chemical and physical identity of the pollutants Types of activities that cause emissions Time period over which the emissions were estimated Geographic area covered Clear description of estimation methodologies used and data collected The Inventory of U.S. Greenhouse Gas Emissions and Sinks provides important information about greenhouse gases, quantifies how much of each gas was emitted into the atmosphere, and describes some of the effects of these emissions on the environment. ------- hat are Greenhouse Gases? Many chemical compounds found in the earth's atmosphere act as greenhouse gases, trapping outgoing terrestrial radiation and warming the earth's atmosphere. Some emissions of greenhouse gases occur naturally, while others result from human activities. Carbon dioxide, methane, nitrous oxide, and ozone are greenhouse gases that have both natural and human-related emission sources. In addition, humans have created other greenhouse gases, such as hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). The global warming potential (GWP) of a greenhouse gas is the ratio of global warming, or radiative forcing, from the emission of one unit mass of a greenhouse gas to that of one unit mass of carbon dioxide over a specified time horizon. Calculation of GWPs is based on the lifetime of the gas and how efficiently it traps heat in the atmosphere. See the Inventory Fast Facts data card for a table of GWP values. Changes in Atmospheric Concentration of CO2, CH4, and N2O CD o I 360 „ 340 §- 320 ^300 0 280 260 1750 J? 1500 Q. Q. ~ 1250 O 1000 750 310 § 290 O CM Z 270 250 Carbon Dioxide Methane . Nitrous Oxide 1.5 1.0 0.5 0.0 0.5 0.4 0.3 0.2 0.1 0.0 0.15 0.10 0.05 0.0 1000 1200 1400 1600 1800 2000 Year Source: IPCC Third Assessment Report (2001) ra S a: hat is the Inventory of U.S. Greenhouse Gas Emissions and Sinks? The Inventory of U.S. Greenhouse Gas Emissions and Sinks is a cata- log of anthropogenic, or human-generated, greenhouse gas emissions in the United States. Carbon dioxide can also be sequestered (i.e., stored) in "sinks" that result from forestry and other land-use prac- tices. Excluding all naturally occurring greenhouse gas emissions and sinks, the Inventory provides a detailed record of all emissions and sinks directly attributable to human activities. It does not address naturally occurring emissions or sinks. Trends in Atmospheric Concentrations and Anthropogenic Emissions of Carbon Dioxide Source: Oak Ridge National Laboratory (2001) ------- The gases covered in the U.S. Inventory include: Carbon Dioxide (C02J In nature, carbon is cycled between various atmospheric, oceanic, biotic, and mineral reservoirs. In the atmosphere, carbon mainly exists in its oxidized form as C02. Carbon dioxide is released into the atmosphere primarily as a result of the burning of fossil fuels (oil, natural gas, and coal) for power generation and in transportation. It is also emitted through various industrial processes, forest clear- ing, natural gas flaring, and biomass burning. And, some carbon is sequestered in forest and agricultural soils. Methane (CH4) Methane is produced primarily through anaerobic decomposition of organic matter in biological systems. Specifically, methane is emitted as a result of the decomposition of organic wastes in municipal solid waste landfills and from agricultural and biological processes related to wetland rice cultivation, livestock digestion, and waste production. Methane emissions also occur during the production and distribution of fossil fuels such as coal, natural gas, and petroleum. Methane's overall contribution to global warming is significant because it is estimated to be more than 20 times as effective at trapping heat in the atmosphere than C02. Nitrous Oxide (N20) The microbial processes of nitrification and denitrification naturally produce nitrous oxide in soils. Anthropogenic additions of nitrogen to soils during agricultural soil management activities increase the amount of N20 emitted to the atmosphere. Nitrous oxide is also emitted during industrial production activities, solid waste com- bustion, and fossil fuel combustion. Nitrous oxide is approximately 300 times more powerful than C02 at trapping heat in the atmosphere. MFCs, PFCs, and SF6 Hydrofluorocarbons (MFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6) are powerful greenhouse gases. MFCs are primarily used as replacements for ozone-depleting substances, but also are emitted as a by-product of the HCFC-22 manufacturing process. PFCs and SF6 are emitted by a variety of industrial processes including aluminum smelting, electric power transmission and distribution, magnesium processing, and semiconductor manufacturing. Currently, MFCs, PFCs, and SF6 have a relatively small aggregate radia- tive forcing impact; however, because some of them have long atmospheric lifetimes, their concentrations can irreversibly accumulate in the atmosphere. missions by Sector Emissions of greenhouse gases result from many of the industrial, transportation, agricultural, and other activities that take place in the United States. The following is a description of the various sectors that emit greenhouse gases. Energy Historically, energy-related activities have accounted for more thai three-quirters of GWP-weighted greenhouse gas emissions. Most of these arf carbp"- air,. -~ emissions; however, some emissions of methane and nitrous o:;ide also re?ut from stationary and mobile combustion. Almost all emissions Tom the energ r sector result from fossil fuel combustion, which includes the birning of coal, natural gas, and petroleum. Fossil fuel combustion from stationar> sources, such as electricity generation, represents more than half of energy-relate 1 emissions, while combustion of fossil fuels by mobile sources, such as automobiles, rep- resents approximately one-third. In addition to fossil fuel combustion-relate J activities, carbon dioxide is also emitted as a result of natural gas flaring and biomass burning, and methane is emitted through coal mining as well as the pro- duction, processing, transmission, and dis- tribution of natural gas and petroleum. Industrial Processes Industrial processes emit greenhouse gases as a by-product of various non- energy related industrial activities. Manufacture of cement, lime, soda ash, iron, steel, aluminum, ammonia, titanium dioxide, and ferroalloys produces carbon dioxide as a by-product. The consumption of limestone, dolomite, and carbon dioxide as raw materials in industrial applications also releases carbon dioxide emissions. The production of petrochemicals and silicon carbide result in small amounts of methane emissions, while producing nitric and adipic acid generates nitrous oxide emissions. Emissions of HFCs, PFCs, and SF6 are particularly important as substitutes for ozone-depleting substances such as chlorofluorocarbons (CFCs). These gases may also be emitted as a result of aluminum and HCFC-22 production, semiconductor manufacturing, electrical transmission and distribution, and magnesium production and processing. ------- Agriculture Agricultural activities contribute directly to emissions of methane and nitrous oxide. The majority of nitrous oxide emissions occur because cropping and fertilizer practices increase the quantity of reactive nitrogen in the soils. This occurs through application of commercial fertilizers, livestock manure, and sewage sludge; production of nitrogen-fixing crops and forages; retention of crop residues on the field; and the cultivation of soils high in organic matter. These activities make more nitrogen available for the generation of nitrous oxide through micro- bial activity. The normal digestive processes in ruminant livestock (known as enteric fermentation) account for the largest portion of methane emissions. The agriculture sector also emits methane and nitrous oxide from managed and unmanaged manure, rice cultivation, and the burning of agricultural residues. Land-Use Change and Forestry The natural carbon fluxes between biomass, soils, and the atmosphere change when humans alter the terrestrial biosphere through land-use, changes in land-use, and forest management practices. Various forest, agricultural soil, and land management practices can result in the uptake (i.e., sequestration) or emission of carbon dioxide. If these activities result in a net removal of carbon dioxide (versus net emission), they can offset a portion of total greenhouse gas emissions each year. Forestlands con- tribute the most to the net uptake of carbon dioxide, followed by agricultural soils. . j ~ i Waste Waste management and treatment activities are another source of greenhouse gas emissions in the United States. Landfills are the nation's largest source of anthro- pogenic methane emissions. Wastewater treatment systems, including human sewage treatment, are sources of methane and nitrous oxide emissions. ------- To download a free copy of the current edition of the Inventory, to download emissions data, or for more information, visit our Web site at www.epa.gov/globalwarming/publications/emissions or contact: U.S. Greenhouse Gas Inventory Program ghginventory@epa.gov To order a free copy of the current edition of the Inventory, order online at http://yosemite.epa.gov/ncepihom/nsCatalog.nsf/SearchPubs or call (800) 490-9198. Other Useful Links U.S. EPA's Global Warming site www.epa.gov/globalwarming Intergovernmental Panel on Climate Change Web site www.ipcc.ch United Nations Framework Convention on Climate Change Web site www.unfccc.de United States Environmental Protection Agency EPA 430-F-02-008 April 2002 Office of Air and Radiation (6204N) Washington, DC 20460 Recycled/Recyclable Printed with Vegetable Oil Based Inks on Recycled Paper (Minimum 50% Postconsumer) Process Chlorine Free ------- The U.S. Inventory of Greenhouse Gas Emissions and Sinks: U.S. Greenhouse Gas Emissions and Sinks (Tg CO2 Equivalents) ^^^^^^^^^^^^^^•^^•^^•^^•^^•^1 C02 4,998.5 ; 4,943.2 ; 5,045.9 ; 5,157.3 ; 5,261.0 ; 5,305.9 ; 5,483.7 ; Fossil Fuel Combustion 4,779.8 ; 4,733.0 ; 4,836.0 ; 4,950.9 ; 5,047.2 ; 5,085.0 ; 5,266.6 ; Iron and Steel Production 85.4 ! 76.2 ! 75.0 ! 69.9 ! 73.6 ! 74.4 ! 68.3 ! Cement Manufacture 33.3 \ 32.5 \ 32.8 \ 34.6 \ 36.1 \ 36.8 \ 37.1 \ Indirect C02 Emissions 30.9 ! 30.7 ! 30.5 ! 29.5 ! 29.3 ! 29.5 ! 28.9 ! Waste Combustion 14.1 i 15.8 i 16.3 i 17.2 i 17.9 \ 18.6 i 19.6 \ Ammonia Manufacture 18.5 ; 18.7 ; 19.5 ; 18.7 ; 19.5 ; 18.9 ; 19.5 ; Lime Manufacture 11.2 ; 11.0 ; 11.4 ; 11.6 ; 12.1 ; 12.8 ; 13.5 ; Limestone and Dolomite Use 5.2 j 5.0 j 4.5 j 4.1 i 5.2 i 7.0 i 7.4 i Natural Gas Flaring 5.5 \ 5.6 \ 5.1 \ 6.5 \ 6.6 \ 8.7 \ 8.2 \ Aluminum Production 6.3 ; 6.4 ; 6.3 ; 5.8 ; 5.1 ; 5.3 ; 5.6 ; Soda Ash Manufacture and Consumption 4.1 i 4.0 i 4.1 i 4.0 i 4.0 i 4.3 i 4.2 i Titanium Dioxide Production 1.3 ; 1.3 ; 1.5 ; 1.6 ; 1.7 ; 1.7 ; 1.7 ; Ferroalloys 2.0 i 2.0 i 2.0 i 2.0 i 1.8 I 1.9 i 2.0 i Carbon Dioxide Consumption 0.8 ; 0.8 ; 0.9 ; 0.9 j 0.9 i 1.0 i 1.1 i Land-Use Change and Forestry (Sink)> (1,097.7) \ (1,085.6) \ (1,091.1) \ (1,113.8) \ (1,117.8) \ (1,110.0) \ (1,108.1) \ International Bunker Fuelsb 113.9 ! 119.9 ! 109.9 ! 99.8 ! 98.0 ! 101.0 ! 102.3 ! CH4 651.3 i 651.0 i 656.7 i 648.9 i 653.3 i 657.6 i 643.7 i Landfills 213.4 i 213.2 i 215.8 i 217.8 i 217.8 i 216.6 i 211.5 i Enteric Fermentation 127.9 i 127.2 i 130.2 i 128.5 i 130.1 i 133.2 i 129.6 i Natural Gas Systems 121.2 ; 122.7 ; 124.5 ; 129.0 ; 127.3 ; 125.7 ; 126.6 ; Coal Mining 87.1 ; 83.7 ; 81.4 ; 69.7 ; 70.3 ; 73.5 ; 68.4 ; Manure Management 29.2 ; 31.1 j 30.7 ; 31.6 j 33.8 ; 34.8 ; 34.2 ; Wastewater Treatment 24.3 \ 24.6 \ 25.2 \ 25.6 \ 26.2 \ 26.8 \ 27.0 \ Petroleum Systems 26.4 ; 26.8 ; 25.9 i 25.0 i 24.6 i 24.2 i 24.0 i Stationary Sources 7.9 i 8.0 i 8.3 i 7.8 i 7.8 i 8.2 i 8.4 i Rice Cultivation 7.1 ; 7.0 ; 7.9 ; 7.0 ; 8.2 ; 7.6 ; 7.0 ; Mobile Sources 4.9 ; 4.9 ; 4.9 ; 4.9 ; 4.8 ; 4.8 ; 4.7 ; Petrochemical Production 1.2 ; 1.2 ; 1.3 ; 1.4 ; 1.5 ; 1.5 ; 1.6 ; Agricultural Residue Burning 0.7 j 0.6 j 0.8 j 0.6 j 0.8 j 0.7 j 0.7 j Silicon Carbide Production +; +; +; +; +; + ; + ; International Bunker Fuelsb 0.2 i 0.2 i 0.2 i 0.1 i 0.1 i 0.1 i 0.1 i N20 387.3 ; 392.8 ; 402.7 ; 402.0 ; 428.7 ; 419.8 ; 430.5 ; Agricultural Soil Management 267.1 ; 270.1 ; 278.0 ; 273.0 ; 295.1 ; 283.4 ; 292.6 ; Mobile Sources 50.9 ! 53.2 ! 56.4 ! 58.5 ! 60.0 ! 60.4 ! 60.1 ! NitricAcid 17.8 j 17.8 j 18.3 j 18.6 j 19.6 j 19.9 j 20.7 j Manure Management 16.0 ; 16.5 ; 16.3 ; 16.7 ; 16.7 ; 16.4 ; 16.8 ; Stationary Sources 12.8 i 12.7 i 12.9 I 13.1 i 13.4 i 13.5 i 14.1 i Human Sewage 7.0 ; 7.2 ; 7.3 ; 7.5 ; 7.7 ; 7.7 ; 7.8 ; AdipicAcid 14.9 ; 14.7 ; 12.6 ; 13.9 ; 15.4 ; 17.9 ; 17.8 ; Agricultural Residue Burning 0.4 ; 0.4 ; 0.4 ; 0.3 ; 0.5 ; 0.4 ; 0.4 ; Waste Combustion 0.3 j 0.2 j 0.3 j 0.3 j 0.3 j 0.3 j 0.3 j International Bunker Fuelsb 1.0 i 1.0 i 0.9 i 0.9 i 0.9 i 0.9 i 0.9 i MFCs, PFCs, and SF6 93.6 i 88.1 i 89.4 i 94.0 i 92.8 i 98.5 i 111.9 i Substitution of Ozone Depleting Subs 0.9 ; 0.8 i 1.5 i 5.2 ; 8.4 ; 21.8 i 30.6 ; HCFC-22 Production 35.0 ; 30.8 ; 34.9 ; 31.8 ; 31.6 ; 27.0 ; 31.1 ; Electrical Transmission and Distribution 31.2 j 32.5 j 30.2 j 34.1 i 31.4 i 26.5 i 26.8 i Aluminum Production 18.1 \ 15.7 i 14.5 \ 13.9 i 12.2 i 11.8 j 12.5 i Semiconductor Manufacture 2.9 i 2.9 i 2.9 i 3.6 i 3.9 i 5.9 ; 5.4 ; Magnesium Production and Processing 5.5 ; 5.5 ; 5.5 ; 5.4 ; 5.2 ; 5.5 ; 5.5 ; Total 6,130.7 i 6,075.2 i 6,194.8 i 6,302.2 i 6,435.7 i 6,481.8 i 6,669.8 i Net Emission (Sources and Sinks) 5,033.0 i 4,989.6 i 5,103.6 i 5,188.4 i 5,317.9 i 5,371.8 i 5,561.7 i ^^m 5,568.0 5,339.6 76.1 38.3 28.4 21.3 19.5 13.7 8.4 7.6 5.6 4.4 1.8 2.0 1.3 (887.5) 109.9 633.3 206.4 126.8 122.7 68.1 35.8 27.5 24.0 7.5 7.5 4.6 1.6 0.8 + 0.1 429.8 297.5 59.7 21.2 17.1 14.2 7.9 11.5 0.4 0.3 1.0 116.9 38.0 30.0 24.5 11.0 6.5 6.9 6,748.1 5.860.5 ^^M 5,575.1 ; 5,356.2 ; 67.4 ! 39.2 j 28.2 ! 20.3 i 20.1 ; 13.9 ; 8.2 ! 6.3 j 5.8 ! 4.3 i 1.8 ! 2.0 j 1.4 i (885.9) \ 112.9 ! 627.1 j 201.0 ! 124.9 i 122.2 ; 67.9 ; 38.0 ! 27.8 j 23.4 ! 7.0 i 7.9 ; 4.5 ; 1.6 ! 0.8 j + i 0.1 i 426.3 ; 298.4 ; 59.1 ! 20.9 j 17.1 ! 14.3 i 8.1 ; 7.7 ; 0.5 ! 0.2 j 1.0 ! 127.7 i 44.9 ; 40.2 ; 20.1 ! 9.0 j 7.3 ! 6.2 \ 6,756.2 i 5.870.3 i + Does not exceed 0.05 Tg C02 Eq. Notes: Totals may not sum due to independent rounding. Emissions ^^^^^M 5,665.5 i 5,840.0 5,448.6 ! 5,623.3 64.4 ! 65.7 40.0 j 41.1 27.0 ! 26.3 21.8 I 22.5 18.9 \ 18.0 13.5 ! 13.3 9.1 ! 9.2 6.7 ! 6.1 5.9 ! 5.4 4.2 ! 4.2 1.9 I 2.0 2.0 I 1.7 1.6 ! 1.4 (896.4) ! (902.5) 105.3 ! 100.2 620.5 i 614.5 203.1 ! 203.5 124.5 i 123.9 118.6 I 116.4 63.7 ! 61.0 37.6 ! 37.5 28.3 j 28.7 22.3 I 21.9 7.3 ! 7.5 8.3 j 7.5 4.4 ! 4.4 1.7 I 1.7 0.8 j 0.8 + i + 0.1 I 0.1 423.5 i 425.3 296.3 ! 297.6 58.7 ! 58.3 20.1 | 19.8 17.1 ! 17.5 14.6 ! 14.9 8.4 j 8.5 7.7 ! 8.1 0.4 ! 0.5 0.2 | 0.2 0.9 ! 0.9 120.0 ! 121.3 51.3 j 57.8 30.4 ! 29.8 15.5 ! 14.4 8.9 j 7.9 7.7 j 7.4 6.1 I 4.0 6,829.5 I 7,001.2 5,933.1 i 6,098.7 Change from 1990 to 2000 841.5 16.8% 843.4 17.6% (19.7) -23.1% 7.8 23.4% (4.6) -14.9% 8.4 59.5% (0.5) -2.7% 2.1 18.5% 4.0 77.5% 0.5 j 9.9% (0.9) -14.3% 0.0 i 0.9% 0.7 50.1% (0.3) i -13.1% 0.6 ! 70.2% 195.3 -17.8% (13.6) -12.0% (36.8) -5.6% (9.9) -4.7% (4.0) -3.1% (4.9) -4.0% (26.2) j -30.0% 8.3 28.3% 4.5 18.4% (4.6) -17.3% (0.4) -5.0% 0.4 5.3% (0.5) -10.9% 0.5 42.1% 0.1 14.8% (0.0) -57.1% (0.0) -26.4% 38.0 9.8% 30.5 j 11.4% 7.4 14.4% 1.9 j 10.9% 1.5 9.3% 2.1 16.5% 1.4 20.1% (6.8) -45.6% 0.1 24.1% (0.1) -20.7% (0.1) -8.1% 27.7 29.6% 56.8 i 6025.4% (5.2) -14.8% (16.8) -53.7% (10.2) -56.1% 4.5 157.5% (1.5) -27.3% 870.5 i 14.2% 1 065 8 21 2% a Sinks are only included in net emissions total. weighted using GWP values from IPCC Second Assessment Report (1996) b Emissions from International Bunker Fuels are not included in totals. in keeping with UNFCCC reporting guidelines. 1990-2000 Trends Annual Percent Change • Total GHG emissions rose 1 4.2 percent since 1 990 (2.5 percent since 1 999) • Dominant gas emitted was C02, mostly from fossil fuel combustion • Methane emissions decreased by 5.6 percent • Nitrous oxide emissions increased by 9.8 percent • HFC, RFC, and SF6 emissions have grown by over 29.6 percent U <3 J ~ U.S. GHG Emissions by Gas • Carbon Dioxide • Methane Nitrous Oxide • MFCs, PFCs, & SF6 8,000- 7,000 " K AR9 D,D/U ' ' • £. 6 302 D,T"OD u,*rut. ^^^^^^ ^^^^^m ^^^^mm ^^^^^m minimi 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 1% o -1% 21% 2.0% 11.7% I 1 „„ -0.9% T- oj co <3- un O) O) O) O) Ol O) O) O) O) O) in U.S. GHG Emissions 2.9% 125% 1.2% 1.1% 1 0.1% CD r — co O) o O) O) O) O) O O) O) O) O) O T- T- T- T- OJ U.S. Greenhouse Gas Emissions Per Capita and Per Dollar of Gross Domestic Product 140 n 130 - o ^ 120 - II 1 110- ^ 100 ' c 90 - 80 - " O T- OJ CO <3- O) O) O) O) O3 O) O) O) O) RealGDj> Population Emissions per capita *" «^^ Emissions ^^^^ per SGDP LO CD [^ CO O) O O) O) O) O) O) O O) O) O) O) O) O c/EPA United States Environmental Protection Agency Office of Air and Radiation (6204N) • EPA 430-F-02-008 • April 2002 Recycled/Recyclable Printed with Vegetable Oil Based Inks on Recycled Paper (Minimum 50% Postconsumer) Process Chlorine Free ------- The U.S. Inventory of Greenhouse Gas Emissions and Sinks: Global Warming Potentials (100 Year Time Horizon) the cumulative radiative forcing effects of a gas Carbon dioxide (C02) 1 1 over a specified time horizon resulting from the Methane (CH4)* 21 23 emission of a unit mass of gas relative to a Nitrous oxide (N20) 310 296 reference gas. The GWP-weighted emissions of HFC-23 11,700 12,000 direct greenhouse gases in the U.S. Inventory HFC-125 2,800 3,400 are presented in terms of equivalent emissions HFC-134a 1,300 1,300 of carbon dioxide (C02), using units of teragrams HFC-143a 3,800 4,300 of carbon dioxide equivalents (Tg C02 Eq.). HFC-152a 14° 12° Conversion- HFC ??7pa 2 900 3 500 ^0™™ HFC-236fa 6,300 9,400 Tg = O^g = 10^ metric tons HFC-4310mee 1,300 1,500 = 1 million metric tons CF4 6,500 5,700 The molecular weight of carbon is 12, and C2F6 9,200 1 1 ,900 the molecular weight of oxygen is 1 6; there- C4F10 7,000 8,600 fore, the molecular weight of C02 is 44 (i.e., C6F14 7,400 9,000 12 + [16x2]), as compared to 12 for carbon SF6 23,900 22,200 alone. Thus carbon comprises 12/44ths of ' IPCC Second Assessment Report (1996) carbon dioxide by weight. b IPCC Third Assessment Report (2001) Conversion from gigagrams of gas to teragrams The methane GWP includes the direct effects ,. .,a • !• i LL i !• i of rarhon nioxinp pnmva pnt^1 and those indirect effects due to the production of ul Udluun UIUAIUK equivalent. tropospheric ozone and stratospheric water vapor. The indirect effect due to the production of C02 is / r_ \ / Tn \ nntinrlnHoH Tn PO Fn — 1 "9 lYfGWPlYI U 1 lguU2tq- UgasJX(bWK)Xl10oOGa/ Note: GWP values from the IPCC Second Assessment Report are used in accordance with UNFCCC guidelines Guide to Metric Unit Prefixes Atto(a) 1018 .000000000000000001 FemtO (f) 1 0 15 .000000000000001 Pico(p) 1012 .000000000001 Nano (n) 1 0~9 .000000001 Micro(^) 10-6 .000001 Milli(m) 10-3 .001 Centi (c) 10-2 .01 Deci (d) 10-1 -1 Deca (da) 10 10 Hecto (h) 102 100 Kilo(k) 103 ,000 Mega(M) 106 ,000,000 Giga(G) 109 ,000,000,000 Tera(T) 1012 ,000,000,000,000 Peta(P) 1015 ,000,000,000,000,000 Exa(E) 1018 ,000,000,000,000,000,000 Unit Conversions ^H 1 pound = 0.454 kilograms =16 ounces ^^^^H 1 kilogram = 2.205 pounds =35. 27 ounces ^^^H 1 short ton = 0.9072 metric tons =2,000 pounds ^^^^H 1 metric ton = 1.1 023 short tons = 1,000 kilograms ... „ noooo , . 00 0, ro ... ^^^^H 1 cubic meter = 35.315 cubic feet =1,000 liters 1 1 U.S. gallon = 3.78541 liters = 0.03175 barrels = 0.02381 barrels petroleum I 1 liter = 0.2642 U.S. gallons = 0.0084 barrels = 0.0063 barrels petroleum ^^^H 1 barrel = 31.5 U.S. gallons =119 liters = 0.75 barrels petroleum ^^^^H 1 barrel petroleum = 42 U.S. gallons =159 liters • 1 foot = 0.3048 meters = 1 2 inches ^gjjj^g 1 mj|e = 1.609 kilometers =5,280feet ^H 1 kilometer =0.6214 miles = 3,280.84 feet • 1 square mile = 2. 590 square kilometers =640 acres 1 square kilometer = 0.386 square miles =100 hectares • .1acre = 43, 560 square feet = 0.4047 hectares = 4,047 square meters Energy Conversions 2388xio calories The common energy unit used in 23 88 metric tons of cmde oN equiva|ent international reports of greenhouse g 478x-| Q8 gtu gas emissions is the joule. A joule 277j800 ki|owatt_hours is the energy required to move an object one meter with the force of Energy Units one Newton. A terajoule (TJ) is one Btu British therma| unit ^ Btu trillion (1012) joules. A British thermal MBtu Thousand Btu 1x103Btu unit (Btu, the customary U.S. energy MMBtu Million Btu 1x106Btu unit) is the quantity of heat required BBtu BillionBtu 1x109Btu to raise the temperature of one pound fBtu Trillion Btu 1x1 012 Btu of water one degree Fahrenheit at or QBtu Quadrillion Btu 1x1 015 Btu near 39.2 Fahrenheit. Qnnrrp fnr all Hata- // Q Inventnrv nf Rreenhnuze Kx Fmiffinnf anH Q/'nte 1QQH 7nnn (TPA 9009 fm°m cIS'SHoi Fuel Combusted x Carbon Content Coefficient TomSlS x Fraction Oxidized x (44/1 2) May include adjustments for carbon stored in fossil fuel-based products, emissions from international bunker fuels, or emissions from territories Carbon Intensity of Different Fuel Types The amount of carbon in fossil fuels per unit of energy content varies significantly by fuel type. For example, coal contains the highest amount of carbon per unit of energy, while petroleum has about 25 percent less carbon than coal, and natural gas about 45 percent less. Converting Various Physical Units to Energy Units The values in the following table provide conversion factors from physical units to energy equivalent units and from energy units to carbon contents. These factors can be used as default factors, if local data are not available. Conversion Factors to Energy Units (Heat Equivalents) Heat Contents and Carbon Content Coefficients of Various Fuel Types • Carbon Content Coefficients Fraction Fuel Type Heat Content (Tg Carbon/EJ) Oxidized Solid Fuels (TJ/Gg) Anthracite Coal 24.94 25.46 0.99 Bituminous Coal 26.39 24.51 0.99 Sub-bituminous Coal 18.94 24.89 0.99 Lignite 14.21 26.22 0.99 Coke 27.40 24.23 0.99 Unspecified 27.62 24.40 0.99 Gas Fuels (MJ/Cubic Meter) Natural Gas (dry) 36.37 13.71 0.995 Liquid Fuels (MJ/Liter) Crude Oil 34.64 19.14 0.99 Nat Gas Liquids and LRGs 22.56 16.10 0.99 Other Liquids 34.79 19.14 0.99 Motor Gasoline 31.37 18.35 0.99 Aviation Gasoline 30.15 17.89 0.99 Kerosene 33.86 18.69 0.99 Jet Fuel 33.86 18.32 0.99 Distillate Fuel 34.79 18.91 0.99 Residual Oil 37.55 20.37 0.99 Naptha for Petrofeed 31.34 17.19 0.99 Petroleum Coke 35.98 26.40 0.99 Other Oil for Petrofeed 34.79 18.91 0.99 Special Napthas 31.34 18.82 0.99 Lubricants 36.22 19.18 0.99 Waxes 33.07 18.78 0.99 AsphalVRoad Oil 39.63 19.54 0.99 Still Gas 35.83 16.60 0.99 Misc. Products 34.61 19.14 0.99 Notes: For fuels with annually variable heat contents and carbon content coefficients, 1 999 U.S. average values are presented. U.S. fossil fuel energy statistics are generally presented using gross calorific values (GCV) (i.e., higher heating values). However, this data has been adjusted to correspond to international standards, which are to report energy statistics in terms of net calorific values (NCV) (i.e., lower heating values). To convert between gross and net calorific values while accounting for heat associated with the water content of the fuels, the heat content of solid and liquid fuels was multiplied by 0.95, and the heat content of gaseous fuels was multi- plied by 0.90. Dividing by these values will convert from NCV back to GCV. Density Conversions Methane (Natural Gas) 1 cubic meter 35.32 cubic feet 0.676 kilograms Carbon dioxide 1 cubic meter 35.32 cubic feet 1.854 kilograms Natural gas liquids 1 metric ton 11. 60 barrels 1,844.20 liters Unfinished oils 1 metric ton 7.46 barrels 1,186.04 liters Alcohol 1 metric ton 7.94 barrels 1,262.36 liters Liquefied petroleum gas 1 metric ton 11. 60 barrels 1,844.20 liters Aviation gasoline Imetricton 8.90 barrels 1,415.00 liters Naphtha jet fuel Imetricton 8.27 barrels 1,314.82 liters Kerosene jet fuel Imetricton 7.93 barrels 1,260.72 liters Motor gasoline Imetricton 8.53 barrels 1,356.16 liters Kerosene Imetricton 7.73 barrels 1,228.97 liters Naphtha Imetricton 8.22 barrels 1,306.87 liters Residual oil Imetricton 6.66 barrels 1,058.85 liters Lubricants Imetricton 7.06 barrels 1,122.45 liters Bitumen Imetricton 6.06 barrels 963.46 liters Waxes Imetricton 7.87 barrels 1,251.23 liters Petroleum coke Imetricton 5.51 barrels 876.02 liters Petrochemical feedstocks Imetricton 7.46 barrels 1,186.04 liters Special naphtha Imetricton 8.53 barrels 1,356.16 liters Miscellaneous products Imetricton = 8.00 barrels = 1,271.90 liters Note: Gas densities are at room temperature and pressure. For more information on calculating C02 emissions per kWh, download E-GRID at: http://www.epa.gov/a.rmarkets/egr,d/ For other related information, see: http://www.epa.gov/globalwarming http://www.unfcc.de Download the Inventory at: http://www.epa.gov/globalwarming/publications/emissions ------- |