Comparison of Life Cycle Greenhouse Gases from Natural Gas Pathways for Medium and Heavy-Duty Vehicles

Environmental Science and Technology

Volumn 49, Issue 12, 2015, Pages 7123-7133

  Tong, Fan ^a   Jaramillo, Paulina ^a   Azevedo, Inês M L ^a  

^a CARNEGIE MELLON UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

AIRSHIPS; AUTOMOBILES; CARBON; CARBON FOOTPRINT; ELECTRIC VEHICLES; EMISSION CONTROL; ENGINEERING EDUCATION; FUELS; GAS EMISSIONS; GASES; GREENHOUSE GASES; LIFE CYCLE; METHANE; NATURAL GAS; NATURAL GAS TRANSPORTATION; RESEARCH AIRCRAFT; TRACTORS (TRUCK); TRUCKS; VEHICLES;

BATTERY ELECTRIC VEHICLES; CURRENT TECHNOLOGY; EMISSION REDUCTION; EMISSIONS REDUCTION; FUEL TECHNOLOGY; HEAVY DUTY VEHICLES; PARCEL DELIVERY; VEHICLE FUEL EFFICIENCIES;

NATURAL GAS VEHICLES;

NATURAL GAS; PETROLEUM; PROPANE; EXHAUST GAS; GAS; METHANE;

CARBON FOOTPRINT; CARGO; COST-BENEFIT ANALYSIS; DIESEL ENGINE; ELECTRIC VEHICLE; EMISSION CONTROL; EMISSION INVENTORY; ENERGY EFFICIENCY; GLOBAL WARMING; GREENHOUSE GAS; LIFE CYCLE ANALYSIS; METHANE; NATURAL GAS; REFUSE; SHALE; TRAFFIC EMISSION; TRUCKING;

ARTICLE; CARBON FOOTPRINT; GREENHOUSE GAS; LIFE CYCLE; MOTOR VEHICLE; OIL SHALE; ANALYSIS; COMPARATIVE STUDY; EXHAUST GAS; GAS; GREENHOUSE EFFECT;

UNITED STATES;

GASES; GREENHOUSE EFFECT; METHANE; MOTOR VEHICLES; NATURAL GAS; VEHICLE EMISSIONS;

EID: 84934977160     PISSN: 0013936X     EISSN: 15205851     Source Type: Journal    
DOI: 10.1021/es5052759     Document Type: Article

References (95)

1. Tezak, C. (BAIRD) NGVs:Progress on an Uphill Road, (2009. https://baird.bluematrix.com/docs/pdf/e8bd177a-87a5-43cd-8c7f-d8fc23bde70f.pdf.
2. Werpy, M. R., Santini, D., Burnham, A., and Mintz, M. Natural Gas Vehicles: Status, Barriers, and Opportunities; Argonne National Laboratory: Lemont, IL, 2010; http://www.afdc.energy.gov/pdfs/anl-esd-10-4.pdf.
3. Whyatt, G. Issues Affecting Adoption of Natural Gas Fuel in Light- and Heavy-Duty Vehicles; Pacific Northwest National Laboratory: Richland, WA, 2010; http://s3.amazonaws.com/zanran-storage/www.pnl.gov/ContentPages/184758856.pdf.
4. Marbek. Study of Opportunities for Natural Gas in the Transportation Sector; Natural Resources Canada: Ottawa, Ontario, Canada, 2010; http://www.xebecinc.com/pdf/Marbek-NGV-Final-Report-April-2010.pdf.
5. Alan Krupnick Energy, Greenhouse Gas, and Economic Implications of Natural Gas Trucks; Resources for the Future (RFF): 2010; http://www.rff.org/RFF/Documents/RFF-BCK-Krupnick-NaturalGasTrucks.pdf.
6. Krupnick, A. J. Will Natural Gas Vehicles Be in Our Future?; Resources for the Future: Washington, DC, 2011; http://www.rff.org/RFF/Documents/RFF-IB-11-06.pdf.
7. Encouraging Natural Gas Vehicles in Pennsylvania, Allegheny Conference on Community Development (ACCD), 2012. http://www.alleghenyconference.org/NaturalGasVehicles/Resources/ACCDNGVehiclesAnalysis.pdf.
8. ACT Research. The Future of Natural GasEngines in HeavyDuty Trucks: The Diesel of Tomorrow?, (2012. http://www.actresearch.net/wp-content/uploads/2013/04/ACT-NGP.pdf.
9. Deal, A. L. What Set of Conditions Would Make the Business Case to Convert Heavy Trucks to Natural Gas? A Case Study; National Energy Policy Institute: Tulsa, OK, 2012; http://www.tagnaturalgasinfo.com/uploads/1/2/2/3/12232668/natural-gas-for-heavy-trucks.pdf.
10. Knittel, C. R. Leveling the Playing Field for Natural Gas in Transportation; Brookings Institution: Washington, DC, 2012; http://www.brookings.edu/~/media/research/files/papers/2012/6/13%20transportation%20knittel/06-transportation-knittel.pdf.
11. Lee, A., Zinaman, O., and Logan, J. Opportunities for Synergy Between Natural Gas and Renewable Energy in the Electric Power and Transportation Sectors; National Renewable Energy Laboratory (NREL): Golden, CO, 2012; http://www.nrel.gov/docs/fy13osti/56324.pdf.
12. Advancing Technology for America's Transportation Future; National Petroleum Council (NPC): Washington, DC, 2012; https://www.npc.org/FTF-80112.html.
13. U.S. and Canadian Natural Gas Vehicle Market Analysis: Heavy-Duty Vehicle Ownership and Production; TIAX: Lexington, MA, 2012.
14. Natural Gas Vehicles and Fueling; Love's Travel Stops & Country Stores: Oklahoma City, OK, 2014; http://www.loves.com/portals/0/Images/CNG/CNG-WhitePaper05-02-14.pdf.
15. Morse, E. L., Yuen, A., Kleinman, S. M., Wetherbee, C., Thein, T., Michaeli, I., Cunningham, G., and Smith, R. P.; Energy 2020: Trucks Trains & Automobiles; Citi Global Perspectives & Solutions (GPS): New York, 2013; https://ir.citi.com/ROzgbJktqIDIbvbbj8Kae%2BI%2F1te4V9Hh91ex5wFyG1wuStLT5EL8L%2BP7DiZLBZC%2FZIYJ%2BHi13iU%3D.
16. IHS CERA. Fueling the Future with NaturalGas: BringingIt Home, (2014. https://www.fuelingthefuture.org/assets/content/AGF-Fueling-the-Future-Study.pdf.
17. U.S. National Research Council (NRC). Reducing the Fuel Consumption and Greenhouse Gas Emissions of Medium- and Heavy-Duty Vehicles, Phase Two First Report; The National Academies Press: Washington, DC, 2014.
18. Natural Gas in Transportation White Paper; J.B. Hunt Transport Services, Inc.: Lowell, AR, 2014; http://www.jbhunt.com/files/0001723-NATURAL-GAS-WHITE-PAPER-022014.pdf.
19. MacLean, H. L.; Lave, L. B. Evaluating automobile fuel/propulsion system technologies Prog. Energy Combust. Sci. 2003, 29, 1-69
20. Hesterberg, T.; Bunn, W.; Lapin, C. An evaluation of criteria for selecting vehicles fueled with diesel or compressed natural gas Sustain. Sci. Pract. Policy 2009, 5, 20-30
21. Barnitt, R. A.; Brooker, A. D.; Ramroth, L. Model-Based Analysis of Electric Drive Options for Medium-Duty Parcel Delivery Vehicles; National Renewable Energy Laboratory (NREL): Golden, CO, 2010; http://www.nrel.gov/docs/fy11osti/49253.pdf.
22. Delorme, A.; Karbowski, D.; Sharer, P. Evaluation of Fuel Consumption Potential of Medium and Heavy Duty Vehicles through Modeling and Simulation; Argonne National Laboratory: Lemont, IL, 2009; http://www.autonomie.net/docs/6%20-%20Papers/nas-mediumheavyduty-2009.pdf.
23. Karbowski, D.; Delorme, A.; Rousseau, A. Modeling the Hybridization of a Class 8 Line-Haul Truck; Argonne National Laboratory: Lemont, IL, 2010; http://www.autonomie.net/docs/6%20-%20Papers/Heavy%20duty/modeling-the-hybridization.pdf.
24. Gao, Z.; LaClair, T.; Daw, C. S.; Smith, D. E. Fuel Consumption and Cost Savings of Class 8 Heavy-duty Trucks Powered by Natural Gas. Presented at the TRB 92nd Annual Meeting Compendium of Papers, 2013; http://trid.trb.org/view.aspx?id=1241749.
25. Laclair, T.; Gao, Z.; Siekmann, A.; Fu, J.; Calcagno, J.; Yun, J. Truck Technology Efficiency Assessment (TTEA) Project Final Report; Oak Ridge National Laboratory: 2012; http://info.ornl.gov/sites/publications/files/Pub40546.pdf.
26. Daw, C. S.; Gao, Z.; Smith, D. E.; Laclair, T. J.; Pihl, J. A.; Edwards, K. D. Simulated Fuel Economy and Emissions Performance during City and Interstate Driving for a Heavy-Duty Hybrid Truck SAE Int. J. Commer. Veh. 2013, 6 (1) 161-182
27. Zhao, H.; Burke, A.; Zhu, L. Analysis of Class 8 Hybrid-Electric Truck Technologies Using Diesel, LNG, Electricity, and Hydrogen, as the Fuel for Various Applications; Institute of Transportation Studies, University of California: Davis, CA, 2013; http://www.its.ucdavis.edu/research/publications/publication-detail/?pub-id=2003.
28. Zhao, H.; Burke, A.; Miller, M. Analysis of Class 8 truck technologies for their fuel savings and economics Transp. Res., Part D Transp. Environ. 2013, 23, 55-63
29. U.S. Environmental Protection Agency (EPA). MOVES (MotorVehicle Emission Simulator). http://www.epa.gov/otaq/models/moves/ (accessed May 20, 2014).
30. Using LNG as a Fuel in Heavy-Duty Tractors; National Renewable Energy Laboratory (NREL): Golden, CO, 1999; http://www.nrel.gov/docs/fy99osti/24146.pdf.
31. Davies, C.; Findsen, J.; Pedraza, L. Assessment of the Greenhouse Gas Emission Benefits of Heavy Duty Natural Gas Vehicles in the United States; Science Applications International Corporation (SAIC): McLean VA, 2005; http://climate.dot.gov/documents/natgasvehic092205.pdf.
32. Freight Transportation Case Studies: Clean Air Corridor-Enbridge Gas; Transport Canada: North York, Ontario, Canada, 2006; http://tc.gc.ca/media/documents/programs/enbridge-1.pdf.
33. Frey, H. C.; Rouphail, N. M.; Zhai, H.; Farias, T. L.; Gonçalves, G. A. Comparing real-world fuel consumption for diesel- and hydrogen-fueled transit buses and implication for emissions Transp. Res., Part D Transp. Environ. 2007, 12, 281-291
34. Graham, L. A.; Rideout, G.; Rosenblatt, D.; Hendren, J. Greenhouse gas emissions from heavy-duty vehicles Atmos. Environ. 2008, 42, 4665-4681
35. Hesterberg, T. W.; Lapin, C. A.; Bunn, W. B. A comparison of emissions from vehicles fueled with diesel or compressed natural gas Environ. Sci. Technol. 2008, 42, 6437-6445
36. Multi-Fleet Demonstration of Hydraulic Regenerative Braking Technology in Refuse Truck Applications; New West Technologies, LLC: Englewood, CO, 2011.
37. Green Truck Partnership. Case Study-Liquefied NaturalGas (High Pressure Direct Injection), (2012. http://www.rms.nsw.gov.au/documents/about/environment/air/case-study-lng.pdf.
38. Argonne National Laboratory. Case Study-LiquefiedNatural Gas, (2013. http://www.afdc.energy.gov/uploads/publication/lng-case-study-8-2013.pdf.
39. Gallo, J.-B.; Tomić, J. Battery Electric Parcel Delivery Truck Testing and Demonstration; California Hybrid, Efficient and Advanced Truck Research Center (CalHEAT): Pasadena, CA, 2013; http://www.calstart.org/Libraries/CalHEAT-2013-Documents-Presentations/Battery-Electric-Parcel-Delivery-Truck-Testing-and-Demonstration.sflb.ashx.
40. MJB&A. Comparison of Modern CNG, Dieseland Diesel Hybrid-ElectricTransit Buses: Efficiency & Environmental Performance, (2013. http://mjbradley.com/sites/default/files/CNG%20Diesel%20Hybrid%20Comparison%20FINAL%2005nov13.pdf.
41. Chernich, D. J.; Misra, C.; Herner, J.; Collins, J.; Krishnamurthy, M.; Burnitzki, M.; Sobieralski, W.; Ianni, R.; Riemersma, R. In-use Testing of Late Model Diesel, LNG and Hybrid Refuse Trucks During Regular Route Service-Lessons Learned. Presented at 2014 PEMS Conference and Workshop, 2014; http://www.cert.ucr.edu/events/pems2014/liveagenda/18chernich.pdf.
42. Sandhu, G.; Frey, H. C.; Bartelt-Hunt, S.; Jonez, E. Real-World Activity and Fuel Use of Diesel and CNG Refuse Trucks. Presented at 2014 PEMS International Conference & Workshop, 2014; http://www.cert.ucr.edu/events/pems2014/liveagenda/25sandhu.pdf.
43. Beer, T.; Grant, T.; Brown, R.; Edwards, J.; Nelson, P.; Watson, H.; Williams, D. Life-cycle Emissions Analysis of Alternative Fuels for Heavy Vehicles: Stage 1; CSIRO: Aspendale, Victoria, Australia, 2000; http://www.arb.ca.gov/research/seminars/beer/csiro-report.pdf.
44. Beer, T.; Grant, T.; Morgan, G.; Lapszewicz, J.; Anyon, P.; Edwards, J.; Nelson, P.; Watson, H.; Williams, D. Life-Cycle Emissions Analysis of Alternative Fuels for Heavy Vehicles: Stage 2; CSIRO: Aspendale, Victoria, Australia, 2001; http://www.globalbioenergy.org/uploads/media/06-Australian-Greenhouse-Office---Comparison-of-Transport-Fuels.pdf.
45. Ally, J.; Pryor, T. Life-cycle assessment of diesel, natural gas and hydrogen fuel cell bus transportation systems J. Power Sources 2007, 170, 401-411
46. Comparison of Greenhouse Gas Emissions from Natural Gas and Diesel Vehicles; The California Air Resources Board (CARB): 2008; http://www.arb.ca.gov/fuels/lcfs/100708ng-comparison.pdf.
47. Beer, T.; Grant, T.; Williams, D.; Watson, H. Fuel-cycle greenhouse gas emissions from alternative fuels in Australian heavy vehicles Atmos. Environ. 2002, 36, 753-763
48. Clark, N. N.; Zhen, F.; Wayne, W. S.; Lyons, D. W. Transit Bus Life Cycle Cost and Year 2007 Emissions Estimation; Federal Transit Administration, Department of Transportation: Washington, DC, 2007; http://www.fta.dot.gov/documents/WVU-FTA-LCC-Final-Report-07-23-2007.pdf.
49. Alvarez, R. a; Pacala, S. W.; Winebrake, J. J.; Chameides, W. L.; Hamburg, S. P. Greater focus needed on methane leakage from natural gas infrastructure Proc. Natl. Acad. Sci. U. S. A. 2012, 109, 6435-6440
50. Meier, P. J.; Holloway, T.; Luedke, M.; Frost, E. A.; Scotty, E.; Williams, S. P.; Bickford, E. Does Natural Gas Make Sense for Freight? Environmental Implications of the "Pickens Plan"; National Center for Freight & Infrastructure Research & Education, University of Wisconsin-Madison: Madison, WI, 2013; http://www.wistrans.org/cfire/documents/FR-CFIRE0422.pdf.
51. Venkatesh, A.; Jaramillo, P.; Griffin, W. M.; Matthews, H. S. Uncertainty in life cycle greenhouse gas emissions from United States natural gas end-uses and its effects on policy Environ. Sci. Technol. 2011, 45, 8182-8189
52. Santini, D.; Rood Werpy, M.; Burnham, A.; Wallner, T.; Grannis, L.; Laughlin, M. D. Energy Security and Greenhouse Gas Emissions of Natural Gas Heavy-Duty Commercial Trucking. Presented at A&WMA's 106th Annual Conference & Exhibition, 2013.
53. Xu, Y.; Lee, D.; Gbologah, F.; Cernjul, G.; Elango, V.; Rodgers, M.; Guensler, R. Load-Based Life Cycle Greenhouse Gas Emissions Calculator for Transit Buses: An Atlanta, GA, Case Study Green St., Highw., Dev. Proc 2013, 284-294 10.1061/9780784413197.023
54. (S&T)2 Consultants, Inc. GHGenius, (2014. http://www.ghgenius.ca/.
55. Taptich, M. N.; Horvath, A. Bias of Averages in Life-Cycle Footprinting of Infrastructure: Truck and Bus Case Studies Environ. Sci. Technol. 2014) 48, 13045-13052
56. Allen, D. T.; Torres, V. M.; Thomas, J.; Sullivan, D. W.; Harrison, M.; Hendler, A.; Herndon, S. C.; Kolb, C. E.; Fraser, M. P.; Hill, A. D. Measurements of methane emissions at natural gas production sites in the United States Proc. Natl. Acad. Sci. U. S. A. 2013, 110, 17768-17773
57. U.S. Environmental Protection Agency (EPA). Greenhouse GasReporting Program (GHGRP): 2011 Data Sets. http://www.epa. gov/ghgreporting/ghgdata/2011data.html (accessed Nov 10, 2013).
58. Shires, T.; Lev-on, M. Characterizing Pivotal Sources of Methane Emissions from Natural Gas Production: Summary and Analysis of API and ANGA Survey Responses; American Petroleum Institute (API): Washington, DC, 2012; http://www.api.org/~/media/Files/News/2012/12-October/API-ANGA-Survey-Report.pdf.
59. Allen, D. T.; Pacsi, A. P.; Sullivan, D. W.; Zavala-Araiza, D.; Harrison, M.; Keen, K.; Fraser, M. P.; Daniel Hill, A.; Sawyer, R. F.; Seinfeld, J. H. Methane Emissions from Process Equipment at Natural Gas Production Sites in the United States: Pneumatic Controllers Environ. Sci. Technol. 2015, 49 (1) 633-640
60. Allen, D. T.; Sullivan, D. W.; Zavala-Araiza, D.; Pacsi, A. P.; Harrison, M.; Keen, K.; Fraser, M. P.; Daniel Hill, A.; Lamb, B. K.; Sawyer, R. F. Methane Emissions from Process Equipment at Natural Gas Production Sites in the United States: Liquid Unloadings Environ. Sci. Technol. 2015, 49 (1) 641-648
61. Brantley, H. L.; Thoma, E. D.; Squier, W. C.; Guven, B. B.; Lyon, D. Assessment of Methane Emissions from Oil and Gas Production Pads using Mobile Measurements Environ. Sci. Technol. 2014, 48 (24) 14508-14515
62. Life-Cycle Cost Model and Pollutant Emissions Estimator; TIAX: Cupertino, CA, 2008; http://s3.amazonaws.com/zanran-storage/www.westport.com/ContentPages/16679159.pdf.
63. Meyer, P. E.; Green, E. H.; Corbett, J. J.; Mas, C.; Winebrake, J. J. Total fuel-cycle analysis of heavy-duty vehicles using biofuels and natural gas-based alternative fuels J. Air Waste Manage. Assoc. 2011, 61, 285-294
64. Greszler, A. D. (Volvo) Heavyduty truck technologies for reducing fuel consumption and GHG emissions, (2011. http://www.its.ucdavis.edu/files/general/pdf/2013-07-30-Asilomar-2011-Greszler.pdf.
65. MJB&A. Clean Diesel versus CNG Buses:Cost, Air Quality,& Climate Impacts, (2012. http://www.catf.us/resources/publications/files/20120227-Diesel-vs-CNG-FINAL-MJBA.pdf.
66. Final Rulemaking to Establish Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles: Regulatory Impact Analysis; U.S. Environmental Protection Agency (EPA), U.S. Department of Transportation (DOT), National Highway Traffic Safety (NHTSA): Washington, DC, 2011; http://www.epa.gov/oms/climate/documents/420r11901.pdf.
67. U.S. National Research Council (NRC). Technologies and Approaches to Reducing the Fuel Consumption of Medium- and Heavy-Duty Vehicles; The National Academies Press: Washington, DC, 2010.
68. Reyna, J. L.; Chester, M. V.; Ahn, S.; Fraser, A. M. Improving the Accuracy of Vehicle Emissions Profiles for Urban Transportation Greenhouse Gas and Air Pollution Inventories Environ. Sci. Technol. 2015, 49 (1) 369-376
69. U.S. Environmental Protection Agency (EPA); U.S. Department of Transportation (DOT); National Highway Traffic Safety Administration (NHTSA). Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles, Final Rule, 40 CFR Parts 85, 86, 600, 1033, 1036, 1037, 1039, 1065, 1066, and 1068; 49 CFR Parts 523, 534, and 535; U.S. EPA: Washington, DC, 2011; pp 57105-57513.
70. Environmental Defense Fund (EDF). Gathering Facts to FindClimate Solutions: An Unprecedented Look at Methane from the NaturalGas System. https://www.edf.org/sites/default/files/methane-studies-fact-sheet.pdf (accessed Oct 5, 2014).
71. California Air Resources Board (CARB). Low Carbon Fuel StandardProgram. http://www.arb.ca.gov/fuels/lcfs/lcfs.htm (accessed Jan 20, 2015).
72. U.S. Environmental Protection Agency (EPA). Regulations& Standards: Heavy-Duty. http://www.epa.gov/otaq/climate/regs-heavy-duty.htm (accessed Jan 20, 2015).
73. U.S. Energy Information Agency (EIA). Annual Energy Outlook, (2014. http://www.eia.gov/forecasts/aeo/.
74. Spath, P. L.; Mann, M. K. Life Cycle Assessment of a Natural Gas Combined-Cycle Power Generation System; National Renewable Energy Laboratory (NREL): Golden, CO, 2000; http://library.umac.mo/ebooks/b28020261.pdf.
75. Spath, P. L.; Mann, M. K. Life-Cycle Assessment of Hydrogen Production via Natural Gas Steam Reforming; National Renewable Energy Laboratory (NREL): Golden, CO, 2011; http://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/27637.pdf.
76. U.S. and Canadian Natural Gas Vehicle Market Analysis: Comparative and Scenario Analysis; TIAX: Cambridge, MA, 2012.
77. Harrington, W.; Krupnick, A. Improving Fuel Economy in Heavy-Duty Vehicles. Resources for the Future, 2012. http://www.rff.org/RFF/Documents/RFF-IB-12-01.pdf.
78. Brandt, A. R.; Heath, G. A.; Kort, E. A.; O'Sullivan, F.; Pétron, G.; Jordaan, S. M.; Tans, P.; Wilcox, J.; Gopstein, A. M.; Arent, D. Methane leaks from North American natural gas systems Science 2014, 343, 733-735
79. Weber, C. L.; Clavin, C. Life cycle carbon footprint of shale gas: Review of evidence and implications Environ. Sci. Technol. 2012, 46, 5688-5695
80. Miller, S. M.; Wofsy, S. C.; Michalak, A. M.; Kort, E. A.; Andrews, A. E.; Biraud, S. C.; Dlugokencky, E. J.; Eluszkiewicz, J.; Fischer, M. L.; Janssens-Maenhout, G. Anthropogenic emissions of methane in the United States Proc. Natl. Acad. Sci. U. S. A. 2013, 110, 20018-20022
81. U.S. Energy Information Agency (EIA). Midwest propane marketstighten further on cold weather, 2014. http://www.eia.gov/todayinenergy/detail.cfm?id=14711 (accessed Mar 20, 2014).
82. Federal Highway Administration (FHWA). Highway Statistics2010. http://www.fhwa.dot.gov/policyinformation/statistics/2010/ (accessed Aug 20, 2014).
83. U.S. Environmental Protection Agency (EPA). Greenhouse GasReporting Program. http://www.epa.gov/ghgreporting/ (accessed Nov 10, 2013).
84. Harvey Consulting, LLC. Leaking Profits: The U.S. Oil and Gas Industry Can. Reduce Pollution, Conserve Resources, and Make Money by Preventing Methane Waste; NRDC: New York, 2012; http://www.nrdc.org/energy/files/Leaking-Profits-Report.pdf.
85. ICF International. Economic Analysis ofMethane EmissionReduction Opportunities in the U.S. Onshore Oil and Natural Gas Industries. (2014. https://www.edf.org/sites/default/files/methane-cost-curve-report.pdf.
86. U.S. Environmental Protection Agency (EPA). Oil and Natural Gas Sector: New Source Performance Standards and National Emission Standards for Hazardous Air Pollutants Reviews; Final Rule, 40 CFR Parts 63; U.S. EPA: Washington, DC, 2012; pp 49489-49600. http://www.epa.gov/airquality/oilandgas/pdfs/20120417finalrule.pdf.
87. Revisions to Colorado Air Quality Control Commission's Regulation Numbers 3, 6, and 7 Fact Sheet; Colorado Department of Public Health & Environment: Denver, CO, 2014; http://www.oilandgasbmps.org/docs/CO104-revisions-colorado-air-quality-control-commission-regulation.pdf.
88. Climate Action Plan: Strategy to Reduce Methane Emissions; The White House: Washington, DC, 2014; http://www.whitehouse.gov/sites/default/files/strategy-to-reduce-methane-emissions-2014-03-28-final.pdf.
89. Shine, K. P.; Fuglestvedt, J. S.; Hailemariam, K.; Stuber, N. Alternatives to the Global Warming Potential for comparing climate impacts of emissions of greenhouse gases Clim. Change 2005, 68, 281-302
90. Peters, G. P.; Aamaas, B.; T. Lund, M.; Solli, C.; Fuglestvedt, J. S. Alternative "global warming" metrics in life cycle assessment: A case study with existing transportation data Environ. Sci. Technol. 2011, 45, 8633-8641
91. Kendall, A. Time-adjusted global warming potentials for LCA and carbon footprints Int. J. Life Cycle Assess. 2012, 17, 1042-1049
92. Edwards, M. R.; Trancik, J. E. Climate impacts of energy technologies depend on emissions timing Nat. Clim. Change 2014, 4, 347-352
93. Shindell, D. T.; Faluvegi, G.; Koch, D. M.; Schmidt, G. A.; Unger, N.; Bauer, S. E. Improved attribution of climate forcing to emissions Science 2009, 326, 716-718
94. Laughlin, M.; Burnham, A. Case Study-Compressed Natural Gas Refuse Fleets; Clean Cities, U.S. Department of Energy: Washington, DC, 2014; http://www.afdc.energy.gov/uploads/publication/casestudy-cng-refuse-feb2014.pdf.
95. National Renewable Energy Laboratory (NREL). Clean Cities Guide to Alternative Fuel and Advanced Medium- and Heavy-Duty Vehicles, 2013; http://www.afdc.energy.gov/uploads/publication/medium-heavy-duty-guide.pdf.