HomeMy WebLinkAbout2024 GHG Emissions Inventory Report Revised 09082025
City of Bozeman
2024 Community Greenhouse
Gas Emissions Inventory
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TABLE OF CONTENTS
Table of Figures .................................................................................................................................................................................... i
Table of Tables ..................................................................................................................................................................................... ii
Introduction .......................................................................................................................................................................................... 1
Overview of Emissions ......................................................................................................................................................................... 2
Emissions by Scope ............................................................................................................................................................................. 5
Transmission and Distribution Losses .............................................................................................................................................. 5
Emissions by Sector & Source ............................................................................................................................................................. 6
Stationary Energy .............................................................................................................................................................................. 11
Transportation .................................................................................................................................................................................... 12
Transportation – Aviation ................................................................................................................................................................ 12
Waste & Wastewater.......................................................................................................................................................................... 14
Industrial Processes & Other Scope 3 Emissions ............................................................................................................................... 15
Drivers of Greenhouse Gas Emissions .............................................................................................................................................. 16
Urban Tree Canopy Analysis ............................................................................................................................................................. 18
Per Capita Emissions ......................................................................................................................................................................... 19
Bozeman Climate Plan Goals ............................................................................................................................................................ 20
Summary ........................................................................................................................................................................................... 22
Appendix A: Data Sources ................................................................................................................................................................. 23
Appendix B: Emissions Factors .......................................................................................................................................................... 24
TABLE OF FIGURES
Figure 1. 2024 Bozeman City Limits. .................................................................................................................................................... 1
Figure 2. 2024 Greenhouse gas emissions by sector. .......................................................................................................................... 2 Figure 3. Annual Greenhouse Gas emissions for the City of Bozeman. ............................................................................................... 3
Figure 4. Annual per capita greenhouse gas emissions for the City of Bozeman. ................................................................................ 4
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Figure 5. 2024 Greenhouse gas emissions by scope. .......................................................................................................................... 5
Figure 6. Annual greenhouse gas emissions by sector. ....................................................................................................................... 6
Figure 7. 2024 Greenhouse gas emissions by sector and source. ....................................................................................................... 7
Figure 8. Stationary energy emissions. .............................................................................................................................................. 11
Figure 9. Transportation emissions. ................................................................................................................................................... 12
Figure 10. Air travel at BZN and domestic US airports - US Dept. of Transportation – Bureau of Transportation Statistics ................ 13
Figure 11. Waste emissions. .............................................................................................................................................................. 14 Figure 12. ICLEI Contribution Analysis. .............................................................................................................................................. 17
Figure 13. 2024 Urban Tree Canopy Analysis Landcover Dataset ..................................................................................................... 18
Figure 14. Per capita emissions over time by sector. ......................................................................................................................... 19
Figure 15. Bozeman Climate Plan Goals: Annual Emissions & Reduction Pathway ........................................................................... 21
TABLE OF TABLES
Table 1. 2024 Greenhouse gas emissions by sector, source, and scope. ............................................................................................ 8
Table 2. Contribution Analysis factors. ............................................................................................................................................... 16
Table 3. Local, national, and international per capita emissions. ........................................................................................................ 19
1
INTRODUCTION
Since 2008, the City of Bozeman has tracked community-
wide greenhouse gas (GHG) emissions, and beginning in
2016, has conducted bi-annual GHG inventories following
the Global Protocol for Community-Scale Greenhouse
Gas Emission Inventories (GPC). These inventories,
developed with ongoing guidance from the International
Council for Local Environmental Initiatives (ICLEI), have
enabled Bozeman to identify key emission sources,
observe trends, and understand the drivers of change
across four main sectors: building energy use (stationary
energy), transportation, waste, and industrial processes.
Using 2008 as a baseline year, Bozeman adopted its
Climate Plan in 2020, setting bold targets including a 26%
reduction in emissions by 2025, achieving 100% clean
electricity by 2030, and reaching carbon neutrality by
2050. As the city continues to grow, these bi-annual
inventories play a crucial role in tracking progress,
identifying opportunities for emissions reductions, and
guiding local and individual climate action.
The GHG inventory captures emissions within Bozeman’s
city limits, serving as the geographic boundary for
assessing the scope of emissions by both source and
activity (Figure 1).
Figure 1. 2024 Bozeman City Limits.
2
OVERVIEW OF EMISSIONS
In 2024, Bozeman’s greenhouse gas (GHG) emissions
totaled 705,542 metric tons of carbon dioxide equivalent
(mt CO₂e), encompassing all emissions generated within
the city from building energy use (stationary energy),
transportation, and waste.
Stationary energy was the largest emissions source,
contributing 50% of the total. Within that category,
commercial and industrial buildings accounted for 28%,
while residential buildings made up 22%. Transportation
was the second-largest source, responsible for 38% of
total emissions. Waste and wastewater processes
contributed 11% of total emissions. The remaining 1% of
total emissions are from other industrial processes as well
as indirect upstream and downstream emissions,
generally defined as Scope 3 emissions. For more on
emissions by Scope see Figure 5 on page 5.
Figure 2. 2024 Greenhouse gas emissions by sector.
Residential Buildings22%
Commercial and Industrial Buildings28%
Transportation38%
Waste11%
Industrial Processes0.2%
Other Scope 31%
3
Bozeman’s total greenhouse gas (GHG) emissions in 2024 rose 3% from 2022 and are 35% higher relative to the 2008
baseline. On a per capita basis, emissions showed no change from 2022 and have declined by 17% since 2008. A key
driver of the rise in overall emissions is Bozeman’s rapid population growth, which has increased by 62% between 2008
and 2024. Although population growth has slowed slightly from the average 4% annual increase of the last decade to 3%
between 2022 and 2024, the community is still managing the effects of growth, which have exceeded the emissions forecast
from the 2020 Climate Plan. See Figure 3.
Figure 3. Annual Greenhouse Gas emissions for the City of Bozeman.
523,826 552,116 522,404
607,139 576,868
687,194 705,542
-
10,000
20,000
30,000
40,000
50,000
60,000
70,000
-
100,000
200,000
300,000
400,000
500,000
600,000
700,000
800,000
2008 2012 2016 2018 2020 2022 2024 PopulationAnnual Emissions (mt CO2e)Annual GHG Emissions for the City of Bozeman
Annual Emissions Population
4
While Bozeman’s population continues to grow, surpassing the projections used to set goals in the 2020 Climate Plan, per
capita emissions have decreased. This decline suggests that collective and individual actions have mitigated the growth of
greenhouse gas emissions.
Figure 4. Annual per capita greenhouse gas emissions for the City of Bozeman.
14.7 14.7
11.6 12.5
10.8
12.2 12.2
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10,000
20,000
30,000
40,000
50,000
60,000
70,000
0.0
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4.0
6.0
8.0
10.0
12.0
14.0
16.0
2008 2012 2016 2018 2020 2022 2024 PopulationPer Capita Emissions (mt CO2e)Annual Per Capita GHG Emissions for the City of Bozeman
Per Capita Emissions Population
5
EMISSIONS BY SCOPE
Greenhouse gas emissions are categorized by sector,
scope, and source. When assessing emissions by scope,
each source is evaluated based on where the emissions
are released in relation to the city boundary.
Scope 1 emissions originate within the city limits and
include direct sources such as natural gas consumption,
vehicle use, and local waste processing.
Scope 2 emissions result from the use of grid-supplied
electricity that is produced outside the city and consumed
within it.
Scope 3 emissions occur outside the city boundary but are
driven by activities within Bozeman, such as the disposal
of waste in external landfills.
Figure 5. 2024 Greenhouse gas emissions by scope.
In 2024, Scope 1 emissions accounted for 53% of
Bozeman’s total greenhouse gas emissions, totaling
374,686 metric tons of CO₂e. The primary contributor was
on-road vehicle activity, followed by natural gas use in
both commercial and residential buildings.
Scope 2 emissions represented 25% of total emissions, or
174,018 metric tons of CO₂e. These emissions stem
primarily from the consumption of grid-supplied electricity
in commercial and residential buildings, with a fraction
associated with charging electric vehicles.
Scope 3 emissions made up the remaining 22% (156,838
metric tons of CO₂e). Approximately half of these
emissions were from aviation, while the other half resulted
from sources such as waste and wastewater treatment,
the transport of waste beyond city limits, and transmission
and distribution (T&D) losses from electricity delivery.
Transmission and Distribution Losses
Transmission and distribution (T&D) losses refer to the
portion of electricity lost during the process of delivering
power from generation to end-users. NorthWestern
Energy estimates a T&D loss rate of 6.27%, which equates
to 25,274,794 kilowatt-hours lost while supplying electricity
to Bozeman. These losses resulted in 11,593 metric tons
of CO₂e emissions, accounting for approximately 2% of
the city’s total greenhouse gas emissions.
Scope 153%
Scope 225%
Scope 322%
Emissions by Scope
6
EMISSIONS BY SECTOR & SOURCE
Bozeman’s community-scale greenhouse gas inventory is
organized into four main sectors, each encompassing a range of emission sources: stationary energy,
transportation, waste and waste processes, and industrial
processes.
• Stationary energy includes emissions from
electricity and natural gas use in commercial and
residential buildings, as well as propane and diesel
combustion and transmission and distribution
(T&D) losses.
• Transportation includes emissions from on-road
and off-road gasoline and diesel use, aviation,
public transit, electric vehicle charging, and
associated T&D losses.
• Waste and waste processes account for emissions
from the collection, transport, and treatment of
waste, along with methane released from
decomposing organic materials in landfills.
• Industrial processes consist primarily of emissions from refrigerant leaks in heating, ventilation, and air
conditioning (HVAC) systems.
Figure 6. Annual greenhouse gas emissions by sector.
0 100,000 200,000 300,000
2008
2012
2016
2018
2020
2022
2024
Sector GHG Emissions (mt CO2e)
Emissions by Sector Over Time
Industrial Processes Waste
Residential Buildings Commercial Buildings
Transportation
7
Figure 7. 2024 Greenhouse gas emissions by sector and source.
Residential Fuel Use22%
Commercial Fuel Use28%
Transportation38%
Waste11.4%
Industrial Processes0.2%
Other Scope 30.6%
Residential Electricity12.6%
Residential Natural Gas8.9%Residential Propane0.3%
Fugitive Emissions0.3%Commercial Electricity13.6%
Commercial Natural Gas13.9%
Fugitive Emissions0.5%
Commercial Propane0.1%
On-Road Gasoline15.5%
Aviation10.6%
On-Road Diesel7.1%
Off-Road4.4%
On-Road Electricity0.1%
Transit0.1%
Landfilled9.4%
Closed Landfill1.8%Compost0.1%
Wastewater0.0%Emissions by Sector
and Source
8
Table 1. 2024 Greenhouse gas emissions by sector, source, and scope.
Stationary Energy
Fuel Usage GHG Emissions (mt CO2e) Scope Percentage of Total
Commercial and Industrial Natural Gas 97,822 1 14%
Commercial and Industrial Propane 1,048 1 0.1%
Residential Propane 1,824 1 0.3%
Residential Natural Gas 62,912 1 9%
Residential Wood 249 1 0.04%
Electricity GHG Emissions (mt CO2e) Scope Percentage of Total
Commercial and Industrial Grid-Supplied Electricity 90,015 2 13%
Residential Grid-Supplied Electricity 83,013 2 12%
Commercial and Industrial T&D Losses 6,031 3 1%
Residential T&D Losses 5,562 3 1%
Fugitive Emissions GHG Emissions (mt CO2e) Scope Percentage of Total
Commercial and Industrial 3,180 1 0.5%
Residential 2,045 1 0.3%
Total Stationary Energy 353,699
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Transportation
On-Road Vehicles GHG Emissions (mt CO2e) Scope Percentage of Total
Emissions from fuel combustion on-road transportation occurring in the city 159,287 1 22.6%
Emissions from grid-supplied energy consumed in the city for on-road transportation 989 2 0.1%
EVs T&D Losses 66 3 0.0%
Off-Road GHG Emissions (mt CO2e) Scope Percentage of Total
Off-road fuel use 31,343.1 1 4.4%
Transit GHG Emissions (mt CO2e) Scope Percentage of Total
Transit activities within the city (buses) 501 1 0.1%
Aviation GHG Emissions (mt CO2e) Scope Percentage of Total
Transboundary aviation 74,466 3 10.6%
Total Transportation 266,653
Waste
Community Solid Waste GHG Emissions (mt CO2e) Scope Percentage of Total
Landfilled waste treated outside the City 65,988 3 9.4%
Composted waste treated inside the City 162 1 0.0%
Composted waste treated outside the City 802 3 0.1%
Emissions from closed landfill 12,933 1 1.8%
Wastewater Treatment and Discharge GHG Emissions (mt CO2e) Scope Percentage of Total
Wastewater Generated and Treated in City 313 1 0.0%
Total Waste 80,198
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Industrial Processes and Product Use
Refrigerant Leakage GHG Emissions (mt CO2e) Scope Percentage of Total
Emissions from leaked refrigerants in the City 1,068 1 0.2%
Total Refrigerants 1,068
Other Scope 3
Other Scope 3 GHG Emissions (mt CO2e) Scope Percentage of Total
Emissions from transport, collection, and processing of waste 3,923 3 0.6%
Total Other Scope 3 3,923
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STATIONARY ENERGY
In 2024, stationary energy remained Bozeman’s largest
source of greenhouse gas emissions, contributing 50% of
total community-wide emissions, equal to 353,699 metric
tons of CO₂e. This reflects a 2% decrease from 2022
levels.
The stationary energy sector includes emissions from
electricity and natural gas use in buildings, along with
other fuel sources such as propane, wood, and
transmission and distribution (T&D) losses. Fugitive
emissions from natural gas sourcing, transportation, and
leakage are also included in this sector.
Electricity use, including T&D losses, accounted for 52%
of stationary energy emissions (184,621 mt CO₂e), while
natural gas use, including fugitive emissions, made up
47% (165,958 mt CO₂e). The remaining 1% (3,120 mt
CO₂e) resulted from commercial and residential propane
use as well as residential heating with wood.
Commercial and industrial buildings were responsible for
56% of stationary energy emissions (198,095 mt CO₂e),
representing 28% of Bozeman’s total emissions.
Residential buildings contributed the remaining 44%
(155,604 mt CO₂e), or 22% of total emissions. Emissions
from both building types saw modest reductions from
2022, 1% for commercial and 2% for residential.
Following the lifting of COVID-19 restrictions in 2022, an
increase in commercial energy use was anticipated due to
the return of activity in offices and educational institutions.
Likewise, population growth contributed to higher
residential energy demand between 2020 and 2022.
However, the slight decline in emissions from 2022 to 2024
suggests that both commercial and residential energy use
have stabilized.
Between 2022 and 2024, Bozeman added 54 commercial
businesses and issued 595 certificates of occupancy for
new residences. The overall observed reduction in energy
emissions over this period indicates improvements in
building efficiencies.
Figure 8. Stationary energy emissions.
Residential Electricity23.5%Residential Natural Gas17.8%
Residential Propane0.5%
Residential Wood0.1%Commercial Electricity25.4%
Commercial Natural Gas27.7%
Commercial Propane0.3%Fugitive Emissions1.5%
T&D Losses3.3%
Other
2.4%
Stationary Energy Emissions
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TRANSPORTATION
The transportation sector is Bozeman’s second-largest
source of greenhouse gas emissions, accounting for 38%
of total emissions in 2024, or 266,653 metric tons of CO₂e,
an overall 5% increase from 2022.
On-road vehicles remain the primary source of
transportation emissions. Gasoline-powered vehicles
contributed 41% of the sector’s total emissions (109,368
mt CO₂e), while diesel vehicles accounted for 19%
(49,919 mt CO₂e). Public transit emissions were minimal
at 0.2% (501 mt CO₂e), and electric vehicles, including
associated T&D losses, made up 0.4% (1,055 mt CO₂e).
Aviation contributed 28% of total transportation emissions
(71,830 mt CO₂e), marking a 4% increase from 2022.
Aviation emissions rose significantly between 2020 and
2022 as post-pandemic travel resumed but have since
stabilized.
Off-road sources made up the remaining 12% of
transportation emissions (31,343 mt CO₂e). These include
fuel use from agricultural equipment, private aviation (such
as medical helicopters and aerial surveys), boats,
construction and industrial machinery, lawn and garden
tools, and recreational vehicles like snowmobiles and
ATVs.
In total, Bozeman residents drove 341,284,544 miles in
2024, an 8% increase from 2022, based on vehicle miles
traveled (VMT) estimates from the Montana Department of
Transportation, which are derived from road mileage and
vehicle count models.
Figure 9. Transportation emissions.
Transportation – Aviation
While Bozeman does not have an airport within its city
limits, the Bozeman-Yellowstone International Airport
(BZN), located just a few miles from downtown, functions
as the primary air travel hub for the community. Although
emissions associated with air travel that occurs outside the
City’s boundary are considered optional reporting through
the GPC, the Bozeman-Yellowstone International Airport
is an integral part of the City of Bozeman’s economic
function and is included in the greenhouse gas emissions
inventory to more accurately describe overall community
emissions. Because the associated emissions occur
outside city boundaries, they are categorized as Scope 3
On-Road Gasoline 41.0%
Aviation27.9%
On-Road Diesel 18.7%
Off-Road11.8%
On-Road Electricity0.4%
Transit0.2%
Other0.6%
Transportation Emissions
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emissions. Following ICLEI guidance, these emissions are
estimated based on the proportion of airport passengers
who originate their travel in Bozeman, which serves as a
proxy for the community’s share of jet fuel and aviation
gasoline consumption. In 2024, BZN served 2,642,707
total passengers, with 38% (approximately 1 million
passengers) originating their travel from the airport. This
activity is estimated to have required 7,621,179 gallons of
jet fuel and aviation gasoline, resulting in 74,466 metric
tons of CO₂e emissions. These aviation-related emissions
accounted for 11% of Bozeman’s total greenhouse gas
emissions in 2024.
Aviation emissions are a notable feature of Bozeman’s
2024 greenhouse gas inventory due to their significant rate
of increase following the COVID-19 pandemic. Prior to
2020, air travel at the Bozeman-Yellowstone International
Airport was growing steadily, in line with national trends.
During pandemic-related travel restriction air travel
declined sharply, dropping 58% nationwide and 43% at
BZN.
Between 2020 and 2024, domestic air travel in the U.S.
gradually rebounded to near pre-pandemic levels. In
contrast, BZN experienced a much faster recovery, with
passenger volumes surpassing pre-pandemic levels by
68% (see Figure 10). Although these numbers reflect total
air traffic at BZN and are not solely attributable to
Bozeman residents, the rapid increase in regional air
travel has a significant impact on the community’s overall
emissions.
Figure 10. Air travel at BZN and domestic US airports - US Dept. of
Transportation – Bureau of Transportation Statistics
0
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2018 2019 2020 2021 2022 2023 2024 US Airport Passengers (millions)BZN Airport Passengers (millions)BZN US Air Travel
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WASTE & WASTEWATER
In 2024, waste and wastewater processes accounted for
11% of Bozeman’s total greenhouse gas emissions,
totaling 80,198 metric tons of CO₂e, an 18% increase from
2022.
Ninety-seven percent of Bozeman’s waste is collected and
transported to the Logan Landfill and includes both solid
waste and compostable materials. Solid waste refers to
materials that are not recycled or composted, most of
which are categorized as municipal solid waste (MSW),
such as food scraps, non-recyclable paper, and plastics.
Solid waste also includes other discarded items such as
tires, electronic waste, and construction debris. In 2024,
MSW made up approximately 70% of the city’s landfilled
waste, with a total of 62,835 tons, representing a 23%
increase from the 50,894 tons recorded in 2022. Notably,
organic materials such as paper and food scraps sent to
landfills have a higher global warming potential than if they
were composted or recycled.
Solid waste emissions totaled 53,888 metric tons of CO₂e,
82% of all waste-related emissions, and rose by 22% from 2022. The second-largest contributor to emissions within
this sector is the closed Story Mill Landfill in Bozeman,
which continues to emit methane from previously landfilled
organic material. Although the methane is captured, flared, and converted to carbon dioxide before release, it still
accounts for 16% of waste-related emissions (12,933 mt
CO₂e).
Wastewater treatment added a relatively small portion—
0.4%—of waste sector emissions (313 mt CO₂e), which is
largely dependent on wastewater volume and organic
concentration. A small share of Bozeman’s waste,
including food scraps and other green waste, is
composted locally. In 2024, composted materials
contributed 1% of waste-related emissions (965 mt CO₂e).
Altogether, Bozeman generated 100,929 tons of discarded
material in 2024. The community diverted 10,448 tons
through composting and 2,078 tons through recycling,
avoiding an estimated 10,776 metric tons of CO₂e
emissions.
Figure 11. Waste emissions.
Solid Waste82%
Closed Landfill16%
Compost1%
Wastewater0.4%
Waste Emissions
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INDUSTRIAL PROCESSES & OTHER SCOPE
3 EMISSIONS
In 2024, industrial processes and other Scope 3 emissions
contributed a combined 0.7% of Bozeman’s total
greenhouse gas emissions, totaling 4,991 metric tons of
CO₂e.
Industrial product use primarily refers to emissions from
refrigerant leaks in commercial building HVAC systems.
These are estimated based on the assumption that 25%
of Bozeman’s commercial building space is refrigerated,
with a refrigerant leakage rate of 5%, following the
methodology outlined by the Intergovernmental Panel on
Climate Change (IPCC). Refrigerant leaks accounted for
0.2% of Bozeman’s total emissions (1,068 mt CO₂e).
Other Scope 3 emissions not captured elsewhere in the
inventory stem from the transportation of solid waste to the
Logan Landfill, located outside the city limits. This waste
transport activity contributed 0.6% of total emissions
(3,923 mt CO₂e).
16
DRIVERS OF GREENHOUSE GAS
EMISSIONS
The greenhouse gas emissions inventory provides
insights into the sources and sectors of emissions, and
trends over time. The 2024 GHG inventory offers a clearer
view of what recalibrated emissions may look like for the
Bozeman community following the exceptional
circumstances of the COVID-19 pandemic and the notable
drop in emissions seen in 2020. To complement the GHG
inventory, the ICLEI Contribution Analysis tool offers
valuable insights into the key sources behind changes in
emissions between inventory years.
From 2022 to 2024, overall emissions rose by 3%, a much
smaller increase compared to the 19% jump observed
between 2020 and 2022. The Waste sector saw the
largest increase, rising from 71,311 to 83,808 metric tons
of CO₂e, an 18% increase. While Bozeman’s growing
population continues to be a significant factor in emissions
growth, the second largest contributor in this analysis, the
rise in waste emissions, outpaced population growth,
suggesting an increase in waste generated per person.
Other contributors to rising emissions include an increase
in vehicle miles traveled per person, growth in
employment, and shifts in the electricity and heating fuel
mix.
On the other hand, several factors helped offset these
increases. Milder winters have led to reduced use of
heating fuels, lessening the emissions intensity of
stationary energy. Commercial and residential energy use
has declined, further moderating emissions from that
sector. And by composting organic materials as opposed
to landfilling, waste emissions were reduced.
Additional factors contributing to emissions reductions
include improvements in vehicle fuel efficiency, and a
decrease in methane emissions from the closed Story Mill
Landfill.
Table 2. Contribution Analysis factors.
Contribution Emissions (mt CO2e)
Waste Generation 21,870
Population 10,667
VMT 8,744
Growth in Employment 7,269
Electricity & Heating Fuels
Mix 5,861
Other 4,031
Vehicle Efficiency -2,703
Commercial Energy -4,212
Residential Energy -9,137
Compost -10,205
Warmer Winter -12,712
17
Figure 12. ICLEI Contribution Analysis.
18
URBAN TREE CANOPY ANALYSIS
In addition to the greenhouse gas emissions inventory, the
City of Bozeman conducted an urban tree canopy analysis
by using Summer 2024 aerial imagery and 2023 LiDAR
(Light Detection and Ranging) to create a high-resolution
landcover dataset. The results allow for the quantification
of urban tree canopy within Bozeman City limits and the
calculation of two key estimates: carbon stock, the total
carbon stored in trees and plants, and carbon
sequestration, the process by which trees absorb carbon
through photosynthesis and store it in biomass and soils.
In 2024, the City of Bozeman, including county inholdings,
encompassed 14,706 acres, with an estimated 1,238
acres of urban tree canopy. Based on carbon removal
rates for Montana’s urban areas and carbon storage
estimates for Gallatin County, Bozeman’s urban forest is
estimated to store 61,019 metric tons of carbon and has
the potential to remove 3,380 metric tons of CO₂ per year,
equal to roughly 0.5% of the city’s total greenhouse gas
emissions.
The 2024 urban tree canopy analysis establishes a
baseline for calculating the City’s net balance of tree
canopy carbon emissions and removals, known as carbon
flux. To calculate net GHG emissions and removals from
urban forests as defined by the IPCC gain-loss method,
multiple years of tree canopy coverage data is required.
Future GHG emission inventories will incorporate the
calculation of carbon flux.
While measuring carbon storage and sequestration
provides valuable insight it does not quantify other direct
or indirect benefits of ecosystem services provided by the
urban forest, such as air pollutant removal, stormwater
filtration, and shade that mitigates urban heat and reduces
building cooling demand.
Figure 13. 2024 Urban Tree Canopy Analysis Landcover Dataset
19
PER CAPITA EMISSIONS
Between 2022 and 2024, Bozeman’s per capita greenhouse gas emissions remained steady at 12.2 metric tons of CO₂e
per person and remains 17% lower than the 2008 baseline year. During this same period, Bozeman’s population more than
doubled. The continued decline in emissions per person since 2008 indicates that the city’s rapid population growth has not
led to a proportional rise in total greenhouse gas emissions. Bozeman’s per capita emissions are 14% below the national
average, though still more than two and a half times higher than the global average.
Table 3. Local, national, and international per capita emissions.
Per Capita Emissions (mt CO2e)
2008 2020 2022 2024
Bozeman 14.7 10.8 12.2 12.2
National 18.8 13.5 14.4 14.3
International 4.7 4.5 4.7 4.7
Figure 14. Per capita emissions over time by sector.
0.0
1.0
2.0
3.0
4.0
5.0
6.0
2008 2012 2016 2018 2020 2022 2024mt CO2e Per Capita Emissions Over Time
Commercial and Industrial Buildings Residential Buildings Transportation Solid Waste Industrial Processes
20
BOZEMAN CLIMATE PLAN GOALS
With the adoption of the 2020 Climate Plan, Bozeman set ambitious emissions and energy targets, including a 26%
reduction from 2008 levels by 2025, 100% net clean electricity by 2030, and carbon neutrality by 2050. The emissions
targets align with the 2015 Paris Climate Agreement and the United States’ original targets to reduce greenhouse gas
emissions and adapt to the impacts of climate change. Parties to the Paris Climate Agreement have Nationally Determined
Contributions that are essential to limiting the average global temperature rise to well below 2°C (3.6°F) above pre-industrial
levels, while also pursuing efforts to limit the temperature increase to 1.5°C (2.7°F). Meeting this target does not avoid
extreme, global warming effects, but serves as an agreed aspirational target to avoid the more extreme and irreversible
climate effects expected with 2°C (3.6°F) of warming. Bozeman’s climate targets were adopted in solidarity with the
commitment to limit human-driven warming to 1.5°C, representing meaningful yet daunting benchmarks in a rapidly growing
community.
Figure 14 provides a trend line of Bozeman’s actual GHG inventories dating back to the benchmark year of 2008. The
Climate Plan reduction pathway to carbon neutrality is represented on the green line. The 2024 greenhouse gas emissions
inventory indicates that current emissions are 35% above the 2008 benchmark. Notably, the 2008 benchmark inventory
year excluded Scope 3 aviation emissions. Aviation emissions were previously a minor source of emissions but contributed
10.6% of total emissions in 2024. A correction of the baseline year and subsequent projections relative to our climate goals will be evaluated in future inventories.
Prior inventories have included a business-as-usual (BAU) projection that was developed in 2019. Since the adoption of the Climate Plan, population growth and economic activity have surpassed the assumptions used to develop the BAU projection.
The projection also includes assumptions of incremental efficiency gains under federal policies and economic trends,
suggesting the BAU projection requires a review and update.
Overall, the trend line suggests the need for significant and impactful solutions to bend the emissions growth curve. Progress
towards Bozeman’s climate goals is achievable and relevant. Every tenth of a degree of warming avoided protects human
health and well-being in the Bozeman community and beyond. Improvements to per capita emissions demonstrate that
individuals can pursue a lower-carbon lifestyle in thriving, resilient, connected cities that support more efficient buildings
and infrastructure. Progress towards our goals will require further prioritization and implementation of the Climate Plan,
coupled with supportive state and federal climate policy comprised of consumer incentives, technology investments, and
regulatory oversight.
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Figure 15. Bozeman Climate Plan Goals: Annual Emissions & Reduction Pathway
0.39 0.36
0.52 0.55 0.52
0.61
0.58
0.69 0.71
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Emissions (millions mt CO2e)Bozeman Climate Plan Goals:
Annual Emissions and Reduction Pathway
Climate Plan Goal GHG Emissions Inventory
26% reductionfrom 2008 100%clean electricity
CarbonNeutral
22
SUMMARY
Bozeman’s 2024 greenhouse gas emissions inventory offers a clearer understanding of community-scale emissions
following the impacts of the COVID-19 pandemic, outsized population growth, and increased tourism throughout the
mountain west. While some sectors saw a rise in emissions, others showed stabilization or even reductions. Having a
broader perspective of emissions for the City of Bozeman allows for the reevaluation and prioritization of the solutions and
actions that will bring the community closer to achieving the goals established in the 2020 Climate Plan.
Overall, both emissions and population increased 3% from 2022 to 2024, this marginal decrease in population growth from
years past when Bozeman, experiencing a population boom, saw emissions growth across all sectors. From the previous
inventory year of 2022 to current, sector emissions have begun to stabilize. Both commercial and residential energy use
decreased slightly, indicating reduced energy use in homes and workplaces, as well as the construction of more efficient
buildings. The most significant increase in emissions was observed in the Waste sector, in both total and per capita
measures, highlighting an area the city and community can prioritize for emissions reduction opportunities.
Accelerating the implementation of the solutions and actions outlined in the 2020 Climate Plan will bring Bozeman closer to
achieving its community climate goals for 2025, 2030, and 2050. Ongoing monitoring of community-wide greenhouse gas emissions provides valuable insight into where policy, collaboration, and individual efforts can strengthen progress toward
these goals.
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APPENDIX A: DATA SOURCES
Emissions Source Data Source Were Emissions Estimated or Calculated?
Building Electricity Use NorthWestern Energy Calculated
Building Natural Gas Use NorthWestern Energy Calculated
Building Propane Use US Census ACS House heating Fuel Survey data, Bozeman commercial square footage data, CBECS data, and US EIA unit conversions Estimated
Building Wood Use US Census ACS House heating Fuel Survey data Estimated
Fugitive Emissions from Natural Gas Leakage GPC Protocol default leakage rate Calculated
Transmission & Distribution Losses NorthWestern Energy loss rate Calculated
Vehicle Miles Traveled City of Bozeman and MT DOT Calculated
Vehicle Registrations EPA State Inventory Tool Mobile Combustion Module Calculated
Electric Vehicle Registrations Atlas EV Dashboard Calculated
EV Transmission & Distribution Losses NorthWestern Energy loss rate Calculated
Transit Fuel Use Human Resources Development Council Calculated
Aviation Fuel Use Bozeman/Yellowstone International Airport Calculated
Waste and compost tonnage Gallatin County Solid Waste, City of Bozeman Calculated
Closed landfill emissions Estimated emissions depreciation rate via ICLEI Estimated
Waste transport, collection, and processing emissions GPC Protocol methodology Calculated
Wastewater City of Bozeman Calculated
Refrigerant Leaks Commercial square footage and IPCC methodology Estimated
NorthWestern Energy Electric Emissions Factor NorthWestern Energy N/A
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APPENDIX B: EMISSIONS FACTORS
Stationary Energy Emission Factors—Electricity & Natural Gas
Emission Source GHG Value Unit Source
CO2 0.457 mt CO2/MWh Northwestern Energy's EEI-ESG Template 2023
Electricity CH4 0.00003 mt CH4/MWh EPA's eGrid 2023
N2O 0.000004 mt N2O/MWh
CO2 0.0053 mt CO2/therm
Natural Gas CH4 0.0000005 mt CH4/therm
N2O 0.00000001 mt N2O/therm
CO2 0.00559 mt CO2/gal
Propane CH4 0.000001 mt CH4/gal 2013 ICLEI US Community Protocol: Appendix C
N2O 0.0000001 mt N2O/gal
CO2 93.8 kg/MMBTU
Wood CH4 0.316 kg/MMBTU
N2O 0.0042 kg/MMBTU
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Transportation Emission Factors—Ethanol, Gasoline, and Diesel
Emission Source GHG Value Unit Source
CO2 0.00878 mt CO2/gal
Gasoline CH4 Varies by vehicle g/mile
N2O
CO2 0.01 mt CO2/gal
Diesel CH4 Varies by vehicle g/mile EPA Estimates
N2O
CO2 0.006 mt CO2/gal
Ethanol CH4 Varies by vehicle g/mile
N2O
Off-road Emissions Factors
Emission Source GHG Value Unit Source
CO2 0.00878 mt CO2/gal
Agriculture CH4 6.26 g CH4/mile
N2O 1.05 g N2O/mile
CO2 0.00878 mt CO2/gal
Aviation CH4 3.88 g CH4/mile
N2O 2.13 g N2O/mile EPA Estimates
CO2 0.00878 mt CO2/gal
Boating CH4 3.41 g CH4/mile
N2O 0.05 g N2O/mile
CO2 0.00878 mt CO2/gal
Commercial Industrial CH4 6.13 g CH4/mile
N2O 0.97 g N2O/mile
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Off-road Emissions Factors
Emission Source GHG Value Unit Source
CO2 0.00878 mt CO2/gal
Construction CH4 7.57 g CH4/mile
N2O 1.01 g N2O/mile
CO2 0.00878 mt CO2/gal
Lawn & Garden CH4 6.53 g CH4/mile
N2O 0.92 g N2O/mile EPA Estimates
CO2 0.00878 mt CO2/gal
Recreation CH4 4.29 g CH4/mile
N2O 1.21 g N2O/mile
CO2 0.00878 mt CO2/gal
Miscellaneous CH4 5.44 g CH4/mile
N2O 1.05 g N2O/mile
Transit Emission Factors
Emission Source GHG Value Unit Source
CO2 0.01021 mt CO2/gal
Diesel CH4 0.0095 g CH4/mile EPA Estimates
N2O 0.0431 g N2O/mile
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Aviation Emission Factors
Emission Source GHG Value Unit Source
CO2 9.75 Kg CO2/gal
Jet fuel CH4 0.41 g CH4/gal
N2O 0.08 g N2O/gal Per guidance from ICLEI on emissions
CO2 8.31 kg CO2/gal factors used in the ClearPath tool.
Aviation Gasoline CH4 0.36 g CH4/gal
N2O 0.07 g N2O/gal
Waste Emission Factors
Emission Source GHG Value Unit Source
Municipal Solid Waste CH4 Varies by waste type mt CH4/ ton waste 2013 ICLEI US Community Protocol, Appendix E
Recycled Waste CH4 Varies by waste type mt CH4/ ton waste
N2O mt N2O/ wet short ton waste
Green Waste CH4 0.0036 mt CH4/ ton waste
N2O 0.00004 mt N2O/ ton waste EPA Waste Reduction Model (WARM) Documentation
Food Waste CH4 0.00251 mt CH4/ ton waste
N2O 0.00004 mt N2O/ ton waste
Wastewater CH4 Varies by treatment Varies
2013 ICLEI US Community Protocol, Appendix F
N2O