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[Front Cover]

[Inside Front Cover]

HOW TO OBTAIN COPIES

You can electronically download this document on the U.S. EPA's homepage at http://www.epa.gov/globalwarming/publications/emissions. To request free copies of this report, call the National Service Center for Environmental Publications (NSCEP) at (800) 490-9198, or visit the web site above and click on order “online” after selecting an edition.

All data tables of this document are available for the full time series 1990 through 2000, inclusive, at the web site mentioned above.

FOR FURTHER INFORMATION

Contact Mr. Michael Gillenwater, Environmental Protection Agency, (202) 564-4092, gillenwater.michael@epa.gov.

For more information regarding climate change and greenhouse gas emissions see EPA web side at http://www.epa.gov/globalwarming.

Released for printing: April 15, 2002

[INSERT DISCUSSION OF COVER DESIGN]

EPA 430-R-02-003

INVENTORY OF U.S. GREENHOUSE GAS EMISSIONS AND SINKS:

1990 – 2000

APRIL 15, 2002

U.S. Environmental Protection Agency

1200 Pennsylvania Ave., N.W.

Washington, DC 20460

U.S.A.

U.S. Greenhouse Gas Emissions and Sinks: 1990-2000 4/15/02 Page i

Acknowledgments

The Environmental Protection Agency would like to acknowledge the many individual and organizational contributors to this document, without whose efforts this report would not be complete. Although the complete list of researchers, government employees, and consultants who have provided technical and editorial support is too long to list here, we would like to thank some key contributors and reviewers whose work has significantly improved this year’s report.

In particular, we wish to acknowledge the efforts of the Energy Information Administration and the Department of Energy for providing detailed statistics and insightful analysis on numerous energy-related topics; the U.S. Forest Service for preparing the forest carbon inventory, and the Department of Agriculture’s Agricultural Research Service for their work on nitrous oxide emissions from soils; and to the Department of Agriculture’s Agriculture Research Service and the Natural Resource Ecology Laboratory at Colorado State University for their work on carbon in agricultural soils.

Within the EPA, many Offices contributed data, analysis and technical review for this report. The EPA Office of Atmospheric Programs developed methodologies and provided detailed emission estimates for numerous source categories, particularly for methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. The Office of Transportation and Air Quality and the Office of Air Quality Planning and Standards provided analysis and review for several of the source categories addressed in this report. The Office of Solid Waste and the Office of Research and Development also contributed analysis and research.

Other government agencies have contributed data as well, including the U.S. Geological Survey, the Federal Highway Administration, the Department of Transportation, the Bureau of Transportation Statistics, the Department of Commerce, the National Agricultural Statistics Service, the Federal Aviation Administration, and the Department of Defense.

Michael Gillenwater has directed the analytical development and writing of this report. Work on fuel combustion and industrial process emissions was also directed by Michael Gillenwater. Work on energy and waste sector methane emissions was directed by Elizabeth Scheehle, while work on agriculture sector emissions was directed by Tom Wirth and Joe Mangino. Land-Use Change and Forestry sector analysis was directed by Tom Wirth. Work on emissions of HFCs, PFCs, and SF6 was directed by Deborah Schaefer and Alicia Karspeck. Adam Chambers helped direct the review process for this report.

We would especially like to thank Marian Martin Van Pelt, Randall Freed, and their staff at ICF Consulting’s Global Environmental Practice, including John Venezia, Kim Raby, Katrin Peterson, Barbara Braatz, Leonard Crook, Payton Deeks, Susan Brown, Diana Pape, Bill Cowart, Anne Choate, Noam Glick, and Jeffrey King for synthesizing this report and preparing many of the individual analyses. Eastern Research Group, Raven Ridge Resources, and Arcadis also provided significant analytical support.

U.S. Greenhouse Gas Emissions and Sinks: 1990-2000 4/15/02 Page ii

Preface

The United States Environmental Protection Agency (EPA) prepares the official U.S. Inventory of Greenhouse Gas Emissions and Sinks to comply with existing commitments under the United Nations Framework Convention on Climate Change (UNFCCC).1 Under a decision of the UNFCCC Conference of the Parties, national inventories for most UNFCCC Annex I parties should be provided to the UNFCCC Secretariat each year by April 15.

In an effort to engage the public and researchers across the country, the EPA has instituted an annual public review and comment process for this document. The availability of the draft document is announced via Federal Register Notice and is posted on the EPA web page.2 Copies are also mailed upon request. The public comment period is generally limited to 30 days; however, comments received after the closure of the public comment period are accepted and considered for the next edition of this annual report. The EPA’s policy is to allow at least 60 days for public review and comment when proposing new regulations or documents supporting regulatory development – unless statutory or judicial deadlines make a shorter time necessary – and 30 days for non-regulatory documents of an informational nature such as the Inventory document.

1 See http://www.unfccc.de 2 See http://www.epa.gov/globalwarming/emissions/national

U.S. Greenhouse Gas Emissions and Sinks: 1990-2000 4/15/02 Page iii

Table of Contents

ACKNOWLEDGMENTS I

TABLE OF CONTENTS III

LIST OF TABLES, FIGURES, AND BOXES VII

Tables vii

Figures vii

Boxes xvi

EXECUTIVE SUMMARY ES-1

Recent Trends in U.S. Greenhouse Gas Emissions ES-2

Emissions by Economic Sector [Preliminary Draft] ES-6

Global Warming Potentials ES-8

Carbon Dioxide Emissions ES-11

Methane Emissions ES-16

Nitrous Oxide Emissions ES-19

HFC, PFC, and SF6 Emissions ES-21

Ambient Air Pollutant Emissions ES-24

CHANGES IN THIS YEAR’S INVENTORY REPORT CHANGES-1

Methodological Changes Changes-3

Changes in Historical Data Changes-11

1. INTRODUCTION 1

What is Climate Change? 2

Greenhouse Gases 2

Global Warming Potentials 7

Recent Trends in U.S. Greenhouse Gas Emissions 11

Emissions by Economic Sectors 17

Methodology and Data Sources 22

Uncertainty in and Limitations of Emission Estimates 24

Organization of Report 25

2. ENERGY 27

Carbon Dioxide Emissions from Fossil Fuel Combustion 28

Carbon Stored in Products from Non-Energy Uses of Fossil Fuels 43

Stationary Combustion (excluding CO2) 45

Mobile Combustion (excluding CO2) 50

Coal Mining 55

U.S. Greenhouse Gas Emissions and Sinks: 1990-2000 4/15/02 Page iv

Natural Gas Systems 57

Petroleum Systems 59

Municipal Solid Waste Combustion 62

Natural Gas Flaring and Ambient Air Pollutant Emissions from Oil and Gas Activities 65

Indirect CO2 from CH4 Oxidation 67

International Bunker Fuels 69

Wood Biomass and Ethanol Consumption 74

3. INDUSTRIAL PROCESSES 77

Iron and Steel Production 79

Cement Manufacture 81

Ammonia Manufacture 83

Lime Manufacture 85

Limestone and Dolomite Use 89

Soda Ash Manufacture and Consumption 91

Ferroalloy Production 93

Titanium Dioxide Production 95

Carbon Dioxide Consumption 97

Petrochemical Production 98

Silicon Carbide Production 99

Adipic Acid Production 100

Nitric Acid Production 102

Substitution of Ozone Depleting Substances 104

Aluminum Production 105

HCFC-22 Production 109

Semiconductor Manufacture 110

Electrical Transmission and Distribution 112

Magnesium Production and Processing 113

Industrial Sources of Ambient Air Pollutants 116

4. SOLVENT USE 117

5. AGRICULTURE 119

Enteric Fermentation 120

Manure Management 122

Rice Cultivation 128

Agricultural Soil Management 132

Agricultural Residue Burning 137

6. LAND-USE CHANGE AND FORESTRY 143

U.S. Greenhouse Gas Emissions and Sinks: 1990-2000 4/15/02 Page v

Changes in Forest Carbon Stocks 144

Changes in Carbon Stocks in Urban Trees 150

Changes in Agricultural Soil Carbon Stocks 152

Changes in Yard Trimming Carbon Stocks in Landfills 161

7. WASTE 165

Landfills 165

Wastewater Treatment 169

Human Sewage 172

Waste Sources of Ambient Air Pollutants 174

REFERENCES 177

Executive Summary 177

Changes in this Year’s Inventory 178

1. Introduction 185

2. Energy 186

3. Industrial Processes 197

4. Solvent Use 206

5. Agriculture 206

6. Land-Use Change and Forestry 224

7. Waste 228

ANNEXES 231

List of Annexes 231

ANNEX A: Methodology for Estimating Emissions of CO2 from Fossil Fuel Combustion 233

ANNEX B: Methodology for Estimating Carbon Stored in Products from Non-Energy Us