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Suggested Citation: "9. Resources Summary." National Academies of Sciences, Engineering, and Medicine. 2024. Airport Greenhouse Gas Emissions Inventory: A Primer. Washington, DC: The National Academies Press. doi: 10.17226/27981.

9. Resources Summary

9.1 Global Warming Potentials

Table 9-1 presents GWPs that airport operators may use while calculating their GHG inventories. It is common practice within the United States to use GWPs in use by the national inventory report—the Inventory of U.S. Greenhouse Gas Emissions and Sinks—which usually applies those from the most recent IPCC assessment report.

9.2 Resources for Emissions Calculations

Table 9-2 presents resources that may be useful for emissions calculations.

Table 9-1: Fifth Assessment Report Global Warming Potentials

Chemical	AR5
CO₂	1
CH₄	28
N₂O	265

Table 9-2: Resources for Greenhouse Gas Emissions Calculations

Resource	Calculation Relevance
2006 IPCC Guidelines for National Greenhouse Gas Inventories	Scope 1 Scope 2 Scope 3
EPA Center for Corporate Climate Leadership	Scope 1 Scope 2 Scope 3
EPA GHG Emission Factors Hub	Scope 1 Scope 2 Scope 3
Airport Carbon and Emissions Reporting Tool (ACERT)	Scope 1 Scope 2 Scope 3
The International Organization for Standards: Environmental Management: Greenhouse Gases (ISO 14064)	Scope 1 Scope 2 Scope 3
GHG Protocol Scope 2 Guidance	Scope 2
EPA Emissions & Generation Resource Integrated Database (eGRID)	Scope 2
IPCC 2006 Aircraft Emissions	Scope 3
Greenhouse Gas Protocol Corporate Value Chain (Scope 3) Accounting and Reporting Standard	Scope 3
Greenhouse Gas Protocol Technical Guidance for Calculating Scope 3 Emissions	Scope 3

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9.3 Basic Unit Conversions

Table 9-3 presents common unit conversions used in emissions calculations.

Table 9-3: Basic Unit Conversions

Value	Unit	Equivalent Value	Unit
1.00	U.S. gallons (gal)	3.79	Liters (l)
1.00	Square foot (ft²)	0.09	Square meter (m²)
1.00	Cubic feet (ft³)	0.03	Cubic meter (m³)
1,000,000.00	British thermal units (Btu)	1.06	Gigajoules (GJ)
1.00	U.S. therms	0.11	Gigajoules (GJ)
1.00	Mile (mi)	1.61	Kilometer (km)
1.00	Short tons (tons)	0.91	Metric ton (MT)
1.00	Metric ton (MT)	1,000.00	Kilograms (kg)
1.00	Pounds (lbs)	0.45	Kilograms (kg)
1.00	Megawatt hours (MWh)	1,000.00	Kilowatt hours (kWh)

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9.4 Fuel Units to Energy Conversion

Table 9-4 presents conversions to calculate GJ of energy per unit of fuel for common fuel types.

Table 9-4: Fuel Units to Energy Conversions

GJ per Unit of Fuel
Unit	Aviation Gasoline	Compressed Natural Gas (CNG)	Electricity	Gas/Diesel Oil	Gasoline	Jet Fuel	Liquefied Petroleum Gas (LPG/Propane)	Liquified Natural Gas (LNG)	Natural Gas	Residual Fuel Oil	Steam
Barrels				6.11510458	5.53904400	5.98216752	4.05458021			6.64685280
Btu		0.00000106		0.00000106	0.00000106	0.00000106	0.00000106	0.00000106	0.00000106	0.00000106	0.00000106
CCF		0.10930000						0.10930000	0.10930000
DTH		1.05505600		1.05505600	1.05505600		1.05505600	1.05505600	1.05505600	1.05505600	1.05505600
GJ		1.00000000		1.00000000	1.00000000		1.00000000	1.00000000	1.00000000	1.00000000	1.00000000
kWh		0.00360000	0.00360000	0.00360000	0.00360000		0.00360000	0.00360000	0.00360000	0.00360000	0.00360000
lbs											0.00125974
Liters	0.03344596			0.03846286	0.03483954	0.03762671	0.02550255	0.02282036		0.04180745
M³		0.02800000						0.02800000	0.02800000
MCF		1.09300000						1.09300000	1.09300000
MJ		0.00100000		0.00100000	0.00100000		0.00100000	0.00100000	0.00100000	0.00100000	0.00100000
MLBs											1.25973686
MMBtu	1.05505600	1.05505600		1.05505600	1.05505600	1.05505600	1.05505600	1.05505600	1.05505600	1.05505600	1.05505600
Pounds											0.00125974
Therms		0.10550560		0.10550560	0.10550560		0.10550560	0.10550560	0.10550560	0.10550560	0.10550560
Tonnes								50.43300000
U.S. Gallons	0.12660672			0.14559773	0.13188200	0.14243256	0.09653762	0.08638447		0.15825840

Legend/Source:

EPA GHG Emission Factors Hub

EIA Energy Conversion Calculators

United Kingdom Department for Energy Security and Net Zero Greenhouse Gas Reporting: Conversion Factors 2023

EPA Energy Star® Portfolio Manager® Thermal Energy Conversions

Universal conversion.

No conversion provided.

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9.5 Standards and Guidance

Resource and Hyperlink	Resource Description
ACRP Report 56: Handbook for Considering Practical Greenhouse Gas Emission Reduction Strategies for Airports	Describes best practices for identifying, evaluating, prioritizing, and implementing GHG emission reduction and management strategies for airports.
ACRP Synthesis 65: Practices to Develop Stakeholder Relationships at Smaller Airports	Describes best practices for how smaller airports can proactively and effectively manage stakeholder relationships. See Appendix C for guidance on building effective stakeholder relations.
Airport Carbon Accreditation Program	Provides guidance on emissions management for airports, including guidance for receiving Airport Carbon Accreditation, reducing airport emissions, and offsetting airport emissions.
Aviation Emissions and Air Quality Handbook	Provides guidance for conducting air quality assessments to measure the impact of aviation on air pollutants and GHG emissions in the U.S.
EPA Center for Corporate Climate Leadership: Inventory Management Plan Guidance	Describes the key components of a GHG inventory management plan to help organizations institutionalize the collection, calculation, and maintenance of GHG data.
GHG Protocol Corporate Accounting and Reporting Standard	Provides guidance on preparing a GHG inventory, including identifying operational and organizational boundaries, tracking emissions over time, and best practices for managing the quality of the inventory.
GHG Protocol Mitigation Goal Standard	Provides guidance on designing emission reduction goals and assessing and reporting on progress toward those goals.
GHG Protocol Scope 2 Guidance	Provides guidance for measuring emissions from Scope 2 sources, such as purchased electricity and steam.
Global Protocol for Community-Scale Greenhouse Gas Inventories	Provides guidance for cities on measuring emissions, identify emission reduction strategies, establishing emission reduction goals, and tracking progress toward those goals over time.
Greenhouse Gas Protocol Corporate Value Chain (Scope 3) Accounting and Reporting Standard	Provides guidance for identifying value chain emission sources in order to reduce Scope 3 emissions.
Science-Based Target Setting for the Aviation Sector	Provides guidance on setting emission reduction targets for the aviation sector, focusing primarily on emissions from jet fuel and airlines.
Technical Guidance for Calculating Scope 3 Emissions	Provides guidance for calculating Scope 3 emission sources.
Task Force on Climate-Related Financial Disclosures	Provides recommendations on how companies and organizations can better present climate-related information to support informed capital allocation.
The Corporate Net-Zero Standard	Provides guidance on best practices for establishing and achieving corporate net-zero targets in line with climate science.
The International Organization for Standardization: Environmental Management (ISO 14001 and Related Standards)	Provides criteria for companies to establish effective environmental management systems. ISO 14064 provides guidance on GHG accounting and reporting.

Airport Greenhouse Gas Emissions Inventory: A Primer (2024)

Chapter: 9. Resources Summary

9. Resources Summary

9.1 Global Warming Potentials

9.2 Resources for Emissions Calculations

9.3 Basic Unit Conversions

9.4 Fuel Units to Energy Conversion

9.5 Standards and Guidance

Additional materials

Publication information

Suggested citation

My Academies

Airport Greenhouse Gas Emissions Inventory: A Primer (2024)

Chapter: 9. Resources Summary

9. Resources Summary

9.1 Global Warming Potentials

9.2 Resources for Emissions Calculations

9.3 Basic Unit Conversions

9.4 Fuel Units to Energy Conversion

9.5 Standards and Guidance