Appendix A — Supplementary data

A.1 Emissions factors

Note for solid waste, the global warming potentials used to calculate CO₂e are sourced AR4, not AR5, like the rest of our inventory. However, documentation for the EPA WARM tool (USEPA 2019), indicates that the differences in total CO₂e emissions is negligible.

All EPA Emission Factor Hub values were pulled from an Excel workbook downloaded from the EPA website. Values were processed in epa_ghg_factor_hub.R.

Table A.1: Electricity emission factors. 2021 EPA GHG Emission Factor Hub, EPA eGRID2019, February 2021.

eGrid Subregion	Grid Output	GHG	lb GHG per MWh
MROW (MRO West)	Total output	CO₂	995.80000
MROW (MRO West)	Total output	CH₄	0.10700
MROW (MRO West)	Total output	N₂O	0.01500
MROW (MRO West)	Total output	CO₂	1821.84000
MROW (MRO West)	Total output	CH₄	0.02800
MROW (MRO West)	Total output	N₂O	0.03071

Table A.2: Stationary combustion emission factors. 2021 EPA GHG Emission Factor Hub, Federal Register EPA; 40 CFR Part 98.

Fuel type	GHG	GHG Quantity	Unit	Value
Natural Gas
Natural Gas	CO₂	Kilograms	mmBtu	53.06000
Natural Gas	CH₄	Grams	mmBtu	1.00000
Natural Gas	N₂O	Grams	mmBtu	0.10000
Natural Gas	CO₂	Kilograms	scf	0.05444
Natural Gas	CH₄	Grams	scf	0.00103
Natural Gas	N₂O	Grams	scf	0.00010
Petroleum Products
Kerosene	CO₂	Kilograms	mmBtu	75.20000
Kerosene	CH₄	Grams	mmBtu	3.00000
Kerosene	N₂O	Grams	mmBtu	0.60000
Kerosene-Type Jet Fuel	CO₂	Kilograms	mmBtu	72.22000
Kerosene-Type Jet Fuel	CH₄	Grams	mmBtu	3.00000
Kerosene-Type Jet Fuel	N₂O	Grams	mmBtu	0.60000
Propane	CO₂	Kilograms	mmBtu	62.87000
Propane	CH₄	Grams	mmBtu	3.00000
Propane	N₂O	Grams	mmBtu	0.60000

Table A.3: Solid waste emission factors. 2021 EPA GHG Emission Factor Hub, EPA WARM version 15, November 2020.

Material	Metric tons CO₂e per short ton material
Recycled
Mixed Recyclables	0.09
Mixed Organics	NA
Mixed MSW	NA
Landfilled
Mixed Recyclables	0.68
Mixed Organics	0.48
Mixed MSW	0.52
Combusted
Mixed Recyclables	0.11
Mixed Organics	0.05
Mixed MSW	0.43
Composted
Mixed Recyclables	NA
Mixed Organics	0.17
Mixed MSW	NA

A.2 Global Warming Potential (GWP)

The Global Warming Potential (GWP) was developed to allow comparisons of the global warming impacts of different gases. Specifically, it is a measure of how much energy the emissions of 1 ton of a gas will absorb over a given period of time, relative to the emissions of 1 ton of carbon dioxide (CO₂). The larger the GWP, the more that a given gas warms the Earth compared to CO2 over that time period (USEPA 2023).

Across all sectors, we used the GWP values established in the Intergovernmental Panel on Climate Change (IPCC) 6th Assessment Report (AR6), Table 7.SM.7 (IPCC 2023). We processed these values in global_warming_potential.R.

Table A.4: Global Warming Potential (GWP) values

Gas	100-year GWP value	Source
CO₂	1.0	IPCC AR6 (2021)
CH₄	27.9	IPCC AR6 (2021)
N₂O	273.0	IPCC AR6 (2021)
CF₄	7380.0	IPCC AR6 (2021)
HFC-152a1	164.0	IPCC AR6 (2021)
1 Hydrofluorocarbon-152a, Difluoroethane

A.3 Geographic data

Geographic data were processed in cprg_geography.R.

A.3.1 Counties

County data was pulled using {tigris}, an R package that downloads TIGER/Line shapefiles from the US Census Bureau (Walker 2023). 2021 geographies for Minnesota and Wisconsin were pulled, combined, and saved.

Table A.5: County geography metadata

Column	Class	Description
geoid	character	Five digit county GEOID
county_name	character	County name
county_name_full	character	Full county name
state_name	character	Full state name
statefp	character	State FIPS code
state_abb	character	Abbreviated state name
cprg_area	logical	Whether county is included in the CPRG area
geometry	sfc_MULTIPOLYGON	Simple feature geometry

Additionally, population estimates were obtained from the American Community Survey 5-Year estimates (2017-2021) using {tidycensus} (U.S. Census Bureau 2021).

Table A.6: County population metadata

Column	Class	Description
geoid	character	Five digit county GEOID
county_name	character	County name
state_name	character	Full state name
state_abb	character	Abbreviated state name
population	numeric	Total county population estimate (persons)
population_data_source	character	Population estimate data source

A.3.2 Cities

Minnesota cities, townships, and unorganized territories were imported from Minnesota Geospatial Commons (MnDOT 2023).

Wisconsin cities, towns, and villages were imported from Wisconsin’s Legislative Technology Services Bureau (Wisconsin Legislature 2023).

Data from both states was then combined and filtered to include only the workplan area counties.

Table A.7: City geography metadata

Column	Class	Description
ctu_name	character	City, township, unorganized territory, or village name
ctu_class	character	City class (City, township, unorganized territory, or village)
gnis	numeric	Minnesota geographic identifier
geoid_wis	character	Wisconsin geographic identifier
geometry	sfc_MULTIPOLYGON	Simple feature geometry
county_name	character	County name
state_name	character	Full state name
statefp	character	State FIPS code
state_abb	character	Abbreviated state name
cprg_area	logical	Whether county is included in the CPRG area
geometry	sfc_MULTIPOLYGON	Simple feature geometry

IPCC. 2023. Climate Change 2021 – The Physical Science Basis: Working Group I Contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. 1st ed. Cambridge University Press. https://doi.org/10.1017/9781009157896.

MnDOT. 2023. “City, Township, and Unorganized Territory in Minnesota - Minnesota Geospatial Commons.” Minnesota Geospatial Commons. https://gisdata.mn.gov/dataset/bdry-mn-city-township-unorg.

U.S. Census Bureau. 2021. “ACS Demographic and Housing Estimates.” U.S. Census Bureau. https://data.census.gov/table/ACSDP5Y2021.DP05?g=050XX00US27053_040XX00US27.

USEPA. 2019. “WARM - Management Practices Chapters (Version 15).” Government. US EPA Office of Resource Conservation and Recovery, Prepared by ICF. https://www.epa.gov/sites/default/files/2019-10/documents/warm_v15_management_practices_updated_10-08-2019.pdf.

———. 2023. “Understanding Global Warming Potentials.” Government. April 18, 2023. https://www.epa.gov/ghgemissions/understanding-global-warming-potentials.

Walker, Kyle. 2023. Tigris: Load Census TIGER/Line Shapefiles. Manual. https://CRAN.R-project.org/package=tigris.

Wisconsin Legislature. 2023. “Wisconsin Cities, Towns and Villages (July 2023).” Legislative Technology Services Bureau (LTSB). https://gis-ltsb.hub.arcgis.com/datasets/LTSB::wi-cities-towns-and-villages-july-2023/explore.