HomeMy WebLinkAboutICMunicipalGreenhouseGasUpdate-2017Iowa City Municipal
Greenhouse Gas Emissions
Prepared by the City of Iowa City
Inventory UpdateAugust 2017
Executive Summary .............................................................................................................................................................1
Introduction .........................................................................................................................................................................2
Background .........................................................................................................................................................................2
STAR Community Rating ......................................................................................................................................................3
Purpose and Goals ...............................................................................................................................................................3
Methods ..........................................................................................................................................................................4
Data .................................................................................................................................................................................4
Municipal Results Summary ............................................................................................................................................5
City of Iowa City Municipal Operations Greenhouse Gas Inventory ...................................................................................6
Overview ..........................................................................................................................................................................6
Emissions by Source .........................................................................................................................................................7
Emissions by Sector ..........................................................................................................................................................8
2015 Emissions by Sector ..........................................................................................................................................9
Annual Emissions Comparison by Sector ...................................................................................................................9
Solid Waste Emissions .............................................................................................................................................10
Energy Usage by Sector ..................................................................................................................................................12
2015 Energy Use ......................................................................................................................................................12
Annual Energy Use Comparison ..............................................................................................................................13
Heating and Cooling Days ........................................................................................................................................14
Vehicle and Transit Fuel Use ....................................................................................................................................15
Energy Costs by Sector ...................................................................................................................................................16
2015 Energy Costs ...................................................................................................................................................16
Annual Energy Costs Comparison ............................................................................................................................17
Energy Costs by Source ..................................................................................................................................................18
2015 Energy Costs and Usage by Source .................................................................................................................18
Annual Energy Costs by Source Comparison ...........................................................................................................19
Comparison to Iowa City Community ............................................................................................................................20
Projections .....................................................................................................................................................................21
Population Projections .............................................................................................................................................21
Electricity Emissions Projection ...............................................................................................................................22
Municipal Operations 2025 Total Emissions Projection ...........................................................................................23
Projected Municipal Operations Emissions by Source (2019 & 2025) .....................................................................23
Reducing Emissions ........................................................................................................................................................25
Completed, Ongoing and Future Emissions Reduction Projects by Department .....................................................25
Emissions Reduction Background Information ........................................................................................................27
Potential Municipal Emission Reduction Projects ....................................................................................................27
Next Steps ......................................................................................................................................................................28
Conclusion ......................................................................................................................................................................29
Appendix 1. Municipal Facilities Energy Use, Emissions, and Cost by Site ........................................................................30
Appendix 2. 2015 Emissions Factors .................................................................................................................................31
Appendix 3. Global Warming Potentials ............................................................................................................................32
Appendix 4. Definitions .....................................................................................................................................................33
Appendix 5. Summary of Iowa City’s STAR Rating .............................................................................................................36
Table of Contents
Tables
Table 1. Municipal CO2e Emissions by Sector and Year.......................................................................................................7
Table 2. Municipal CO2e Emissions by Source.....................................................................................................................8
Table 3. Vehicle & Transit CO2e Emissions by Fuel Type .....................................................................................................8
Table 4. Solid Waste Tonnage per Fiscal Year ....................................................................................................................11
Table 5. Municipal Energy Usage by Sector and Year ........................................................................................................12
Table 6. Annual Heating and Cooling Degree Days (2000- 2015) ......................................................................................14
Table 7. 2015 Transit & Fleet Fuel Use ..............................................................................................................................15
Table 8. Municipal Energy Costs by Sector and Year .........................................................................................................16
Table 9. 2015 Municipal Energy Usage and Costs by Source .............................................................................................18
Table 10. Average Energy Cost per Unit (2000, 2008, 2015) .............................................................................................19
Table 11. 2015 Community Emissions Comparison ...........................................................................................................20
Table 12. Iowa City Population Growth & Projection (2000-2050) ....................................................................................21
Figures
Figure 1. Municipal GHG Emissions (2000-2015) ................................................................................................................1
Figure 2. Iowa City's Climate Action Timeline .....................................................................................................................2
Figure 3. Municipal Operations Emissions and Reduction Targets (2000-2015) .................................................................6
Figure 4. 2015 Municipal Operations CO2e Emissions by Source .......................................................................................7
Figure 5. 2015 Municipal Operations CO2e Emissions by Sector ........................................................................................9
Figure 6. Municipal Operations CO2e Emissions by Sector, with Solid Waste (2000, 2008, 2015) ....................................10
Figure 7. Municipal Operations CO2e Emissions by Sector, without Solid Waste (2000, 2008, 2015) ..............................10
Figure 8. Solid Waste CO2e Emissions (2000-2015) ..........................................................................................................11
Figure 9. Solid Waste Tonnage per Year ............................................................................................................................11
Figure 10. 2015 Municipal Operations Energy Usage by Sector ........................................................................................12
Figure 11. Municipal Operations Energy Usage by Sector (2000, 2008, 2015) ..................................................................13
Figure 12. Annual Degree Days & Average Annual Temperature (2000-2015) ..................................................................14
Figure 13. 2015 Municipal Operations Energy Cost by Sector ...........................................................................................16
Figure 14. Municipal Operations Energy Cost by Sector (2000, 2008, 2015) ....................................................................17
Figure 15. 2015 Energy Costs by Source ............................................................................................................................18
Figure 16. 2015 Municipal Operations and Community CO2e Emissions Comparison .....................................................20
Figure 17. Iowa City Population Growth & Projection (2000-2050) ..................................................................................21
Figure 18. Projected CO2e Electricity Emissions with Increasing Renewable Energy (2005-2025) ...................................22
Figure 19. Projected Municipal CO2e Emissions (2005-2025) ...........................................................................................23
Figure 20. Projected Municipal Operations CO2e Emissions by Source in 2019 ...............................................................23
Figure 21. Projected Municipal Operations CO2e Emissions by Source with 100% Renewable Energy ............................24
Table of Contents
Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017 1
Executive Summary
The City has made substantial progress
since 2000 in reducing greenhouse gas
(GHG) emissions, increasing energy
efficiencies and reducing energy costs
in city operations. The goal of this report
is to update the past municipal GHG
inventory (completed in 2009) using
updated data for our new benchmark.
In comparing past inventories, we can
gain understanding of trends over time
to learn what has been successful, as
well as understand how to interpret
what efforts might be most impactful
in reducing future GHG emissions.
This report will also provide baseline
information for creating a plan to reduce
municipal GHG emissions.
Municipal GHG inventories have been
completed for the years 2000, 2008,
and 2015, with estimates calculated for
2002 and 2005. Results are graphed to
the right (Figure 1). In 2015, municipal operations generated 44,194 metric tonnes CO2e, roughly 4.5% of the Iowa City
community’s total emissions. Just over half of all of the municipal emissions were generated by waste in the Iowa City
Landfill. Wastewater treatment generated 15.0%, buildings and facilities generated 12.3%, water treatment generated
5.7%, the vehicle fleet generated 5.0%, the transit fleet generated 4.5%, streetlights and traffic signals generated 3.0%,
and airport facilities generated less than 1%.
The baseline year and targets for GHG reductions used here match those set for the community, though the city
council has not yet set specific reduction targets for municipal operations. In the baseline year of 2005, Iowa City’s
municipal operations emitted an estimated 52,304 metric tonnes CO2e. Emissions have dropped 15.5% from 2005 to
2015.
Emissions have dropped 54.5% from 2000’s total of 97,173 metric tonnes CO2e. Capturing and flaring methane
generated by the Iowa City Landfill began in 2001 and provided the majority of this reduction. Emissions reductions
since 2008 have been driven by increasing renewable energy production, reduced energy use, and increased energy
efficiency.
As our local utility increases renewable energy production in the coming years, municipal operations are projected to
meet a 26-28% reduction in emissions from 2005 levels by 2025. Meeting an 80% reduction in emissions by 2050 will
require significant work, and such a reduction will not be possible with renewable energy alone.
This report reviews trends in GHG emissions, energy usage, and costs of fossil fuels used and produced from municipal
operations. Each of these can vary due to different factors, such as utility and fuel pricing, annual weather patterns,
efficiency measures, and electricity emission factors due to increased renewable energy. In looking to reduce GHG
emissions, cost and feasibility will need to be considered if efforts are to be successful.
* 2002 and 2005 emissions estimated based on average annual emissions change
from 2000 to 2008 combined with the reduction in solid waste emissions that
began in May 2001.
Figure 1. Municipal GHG Emissions (2000-2015)
4
* 2002 and 2005 emissions estimated based on average annual emissions change from 2000 to 2008
combined with the reduction in solid waste emissions that began in May 2001.
Figure 1. Municipal GHG Emissions (2000-2015)
Introduction
Decades of scientific research have concluded that human activities are changing our climate. In
Iowa, climate change causes more frequent extreme storms and floods, increases soil erosion, and
creates a more favorable environment for pathogens and pests (Iowa Greenhouse Gas Inventory &
Reference Case Projections 1990-2025, October 2008). The reduction of greenhouse emissions has
become a serious and pressing matter not just for the planet, but for the Iowa City community as
well.
This municipal greenhouse gas inventory summarizes the greenhouse gas emissions generated by
the City of Iowa City’s municipal operations and supplements the Iowa City community -wide
greenhouse gas inventory. A greenhouse gas inventory allows the City to track changes in
emissions, identify where reductions can be made, and design plans to reduce emissions.
Background
Iowa City began formally working on climate issues in 2007, when Mayor Ross Wilburn signed the
Mayor’s Climate Protection Agreement. In 2008, Iowa City joined the “Cities for Climate Protection
Campaign,” which prompted the creation of a community and municipal greenhouse gas (GHG)
inventory that was completed in August, 2009. Iowa City was the first city in the state of Iowa to
complete a GHG inventory. This report is an update to the 2009 GHG inventory report, which
calculated municipal GHG inventories for the years 2000 and 2008.
On February 17, 2016, Mayor Jim Throgmorton reaffirmed the City’s continued commitment to
addressing climate change by signing a letter to join the U.S. Compact of Mayors. The Compact of
Mayors recently joined with the European Union’s Covenant of Mayors to form the Global
* * 2005 Baseline
28% Reduction from
2005
80% Reduction from
2005
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
CO2e (tonnes) Municipal Operations Greenhouse Gas Emissions
2000-2015
Municipal Emissions 2005 Baseline 2025 Goal 2050 Goal
Decades of scientific research have concluded that
human activities are changing our climate. In Iowa,
climate change causes more frequent extreme storms
and floods, increases soil erosion, and creates a more
favorable environment for pathogens and pests (Iowa
Greenhouse Gas Inventory & Reference Case Projections
1990-2025, October 2008). The reduction of greenhouse
emissions has become a serious and pressing matter not
just for the planet, but for the Iowa City community as
well.
This municipal inventory summarizes the GHG emissions
generated by the City of Iowa City’s municipal operations
and supplements the community-wide GHG inventory.
A GHG inventory allows the City to track changes in
emissions, identify where reductions can be made, and
design plans to reduce emissions.
Background
Iowa City began formally working on climate issues in
2007, when Mayor Ross Wilburn signed the Mayor’s
Climate Protection Agreement. In 2008, Iowa City joined
the “Cities for Climate Protection Campaign,” which
prompted the creation of a community and municipal
GHG inventory that was completed in August 2009. Iowa
City was the first city in the state of Iowa to complete a
GHG inventory. This report is an update to the 2009 GHG
inventory report, which calculated municipal
GHG inventories for the years 2000 and 2008.
On Feb. 17, 2016, Mayor Jim Throgmorton
reaffirmed the City’s continued commitment
to addressing climate change by signing a
letter to join the U.S. Compact of Mayors.
The Compact of Mayors recently joined with
the European Union’s Covenant of Mayors
to form the Global Covenant of Mayors for
Climate and Energy. While cities can work
towards climate mitigation independently,
joining the Covenant of Mayors offers a
recognized framework, provides city staff
with information and support, and connects
Iowa City with other cities around the globe
committed to taking actions to reduce GHG
emissions.
By formally committing to the Global
Covenant of Mayors for Climate and Energy,
Iowa City agreed to complete the following milestones
over a three-year period:
At engagement:
• Mayor makes a formal commitment to reduce GHG
emissions and address climate change risks (signed
Feb. 17, 2016)
Within 1 Year:
• Complete a Community-wide GHG inventory, using
the Global Protocol for Community-Scale GHG
Emissions (submitted December 2016)
• Report local hazards related to climate change
(submitted December 2016)
Within 2 years:
• Set a GHG Reduction Target (Resolution signed Dec.
6, 2016)
• Complete a climate risk vulnerability assessment
Within 3 Years:
• Complete a Climate Action and Adaptation Plan
While the Covenant of Mayors agreement focuses on
community-wide emissions, many local governments
follow these same reductions goals in their municipal
operations to demonstrate their commitment and to
lead by example.
Figure 2. Iowa City’s Climate Action Timeline
Introduction
2 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Introduction
STAR Community Rating
On March 9, 2016, Iowa City was awarded a 4-STAR Community Rating for
sustainability excellence by being formally certified in the STAR (Sustainability Tools
for Assessing and Rating Communities) Community Rating System. Although Iowa
City was the highest-scoring city in the state and achieved high rankings in most
goal areas, the City scored lowest in its Climate and Energy goals. The creation of
the Climate Action and Adaptation Plan, appointment of the Climate Action Steering
Committee, and climate actions undertaken by City staff have been a focus of the City
Council. The STAR framework is a tool that communities can use to quantify these
efforts. City staff held a workshop July 2016 and identified STAR actions items to undertake before recertifying. This
report will fulfill one of the actions identified at a workshop: Conduct a municipal GHG inventory at least every five
years. Iowa City plans on recertifying with STAR in 2020. More information about Iowa City’s STAR rating can be found
at icgov.org/STAR and in Appendix 5.
Purpose and Goals
The purpose of this report is to summarize the results of the municipal GHG inventory using the
Local Government Operations Protocol (LGOP). This data is made available to the Climate Action and
Adaptation Steering Committee and Iowa City residents in order to inform future actions to be taken
by the municipality and community. Emissions-reducing actions will be included in a forthcoming
municipal plan that focuses on emissions from local government operations. Some of these
prioritized actions may be also be included in the community-wide Climate Action and Adaptation
Plan, especially those relating to community services such as waste, water, and wastewater
treatment.
On Dec. 7, 2016, the City Council approved a resolution setting community GHG reduction goals of
26-28% by the year 2025 and 80% by 2050. The baseline year for these reductions is 2005. At the
time the reduction goals were set, they were in alignment with the United States’ targets set by
the Paris Agreement and agreed upon for the United States by President Obama in 2016 (unfccc.
int/paris_agreement/items/9485.php). Despite the United States withdrawal from the Paris
Agreement in 2017, Iowa City remains committed to meeting the reduction targets set by the
agreement. The development and implementation of the Climate Action and Adaptation Plan will
assist in meeting these targets.
As the Council has not yet set specific goals for reductions in municipal operations emissions
reductions, this report assumes reductions targets matching the overall community emissions
reductions targets.
3Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Methods
The methods used in this inventory are consistent with
guidelines outlined by the Local Government Operations
Protocol (LGOP). LGOP was developed by the California
Air Resources Board, the California Climate Action
registry, ICLEI (Local Governments for Sustainability),
and The Climate Registry. The protocol was designed to
provide a consistent methodology for the quantification
and reporting of municipal GHG emissions across U.S.
municipalities.
LGOP groups GHG emissions into three categories: Scope
1, 2, and 3. Scope 1, or direct GHG, includes emissions
generated directly from sources owned and operated
by an organization. Scope 2, or energy indirect GHG,
includes emissions from the use of energy sources
generated outside of the organization (such as electricity
purchased from local utilities). Scope 3, or other indirect
GHG, includes emissions generated as a consequence of
an organization’s activities, but are not directly owned
or controlled by the organization, such as employee
commuting, business travel, and production of goods
purchased by the City.
This report takes into account all emissions generated
by Scope 1 and Scope 2 activities. Scope 3 emissions are
outside of the purview of this report and are not taken
into account.
For this report, City staff totaled GHG emissions
generated from municipal operations by calculating
emissions of carbon dioxide (CO2), methane (CH4), and
nitrous oxide (N2O) from acquired data on energy use
and waste generation. CH4 and N2O were converted
to CO2 equivalent (CO2e), then multiplied by global
warming potential (GWP) units developed by the
Intergovernmental Panel on Climate Change (IPCC).
GWPs were taken from the IPCC Fifth Assessment
Report (2013), and the 100-year GWP units were used in
calculations. The total units of CO2e then represent the
sum total of the global warming potential of calculated
GHGs. Electricity emissions factors were provided by
MidAmerican Energy, Eastern Iowa Light and Power
(EILP), and the Environmental Protection Agency’s
Emissions & Generation Resource Integrated Database
(eGRID). This municipal analysis did not calculate
hydrofluorocarbons (HFCs), perfluorocarbons (PFCs),
sulfur hexafluoride (SF6), or other GHGs. All GHGs are
reported in the standard GHG units of metric tonnes
CO2e. One metric tonne is equivalent to 2,205 U.S.
pounds.
Data
Municipal operations GHG totals included emissions
from all City of Iowa City government activities. This
report includes the total combined energy usage and
emissions from the following sectors:
• Airport Facilities
• Buildings and Facilities
• Solid Waste
• Streetlights and Traffic Signals
• Transit Fleet
• Vehicle Fleet
• Wastewater Treatment
• Water Treatment
Data for this analysis was provided and verified by
various City departments and staff. Energy usage was
collected from City of Iowa City utility bills for sum
totals of electrical, natural gas, and propane usage
and cost. The City has a total of almost 300 natural gas
and electricity accounts from the two local utilities.
MidAmerican Energy supplied two-thirds of electricity
and all of the natural gas for the City of Iowa City. Just
under one-third of electricity was supplied by Eastern
Iowa Light and Power for the wastewater treatment
plant and other facilities located in the southern portion
of Iowa City. Vehicle and transit fuel usage data was
provided by the City Equipment Division and includes all
fuel (gasohol, diesel and propane) for 280 fleet vehicles
and 29 transit vehicles. The Iowa City Landfill provided
data on waste collected throughout Johnson County.
Information from the City’s wastewater treatment plant
was analyzed for CH4 and N2O produced from treatment
procedures. Total electricity and natural gas usage data
for City facilities can be found in Appendix 1.
Introduction
4 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
2015 Municipal Results:
Total municipal operations CO2e emissions: 44,194
metric tonnes
~4.5% of Iowa City community’s total GHG
emissions
Municipal CO2e emissions by source:
54.0% from methane production from waste
in the Iowa City Landfill (which is captured and
flared)
26.4% from electricity use
9.5% from vehicle fuel use
7.3% from natural gas use
2.5% from nitrous oxide generated during
wastewater treatment
Less than one percent from methane (from
wastewater treatment) and propane (for
heating landfill buildings and fuel for forklifts)
Municipal Emissions Dropped:
21.0% since 2008
15.5% since 2005
54.5% since 2000
Major City Energy Use & Emission Reduction
Initiatives 2000-2015
Since 2000, staff across multiple departments have been
working on projects to lower energy use and emissions:
Capturing and flaring methane generated by the
Iowa City Landfill beginning in May 2001, which was
EPA-mandated as an operational requirement
Traffic signals converted to LED (2002-present)
Stimulus funding assisted in the $1.2 million project
to install LED lighting in all five City parking ramps
(2010)
Iowa City was awarded $692,300 in stimulus funding
in 2011-2014 and completed the following projects:
Energy audits for all facilities over 25,000 sq ft
(eight facilities)
Efficient lighting replacements at Mercer Park,
the Robert A. Lee Recreation Center, and the
water and wastewater treatment plants
Efficient aeration blower installed at wastewater
treatment plant
Variable frequency drive (VFD) motors with
higher efficiencies installed at Mercer Aquatic
Center
Purchased energy tracking software to track
municipal energy usage
Hired temporary personnel to track energy usage
and write facility reports
Created a revolving loan fund with energy cost
savings to continue energy retrofits
Three LEED certified buildings - East Side Recycling
Center Education Building (Platinum), Fire Station #2
(Gold), Fire Station #4 (Gold)
Geothermal heat source pumps (no natural gas is
used for building, only electricity) for three facilities:
East Side Recycling Center Education Building, Fire
Station #2, and Fire Station #4
Ongoing LED replacement of City-owned streetlights
(since 2013)
Contract to replace MidAmerican-owned streetlights
with LEDs over 10-year period (2015)
One hybrid vehicle (2008) and three electric
wastewater vehicles (2015, 2016) for the vehicle
fleet
Energy audits for additional City-owned buildings
(2015)
MidAmerican Energy Emission Reduction
Initiatives
35.5% renewable energy in 2015, which increased
from 0% in 2000
Approved by Iowa Utility Board to generate 89%
renewable electricity by 2019
100% renewable electricity goal, sometime after
2019
Eastern Iowa Light and Power Emission Reduction
Initiatives
60% of electricity generation was carbon-free
in 2015; however, the majority of carbon-free
generation was sold as carbon credits and cannot be
claimed in this report
In 2015, 25% of EILP’s electrical generation was
wind/hydro, and 35% was nuclear energy. While EILP
plans to add solar and wind installments over the
next few years, they currently project their overall
carbon-free generation percentage to remain steady
at 60% through 2031
These combined initiatives resulted in a 54.5% reduction
in city operations’ GHG emissions during the period of
2000 to 2015.
Municipal Results Summary
5Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Overview
Municipal GHG inventories have been completed for
2000, 2008, and 2015. Inventories for 2002 and 2005
are estimates, as complete data for those years was not
available at the time of this report. The only sectors not
showing significant emissions reductions from 2008 to
2015 are the solid waste facilities, the vehicle fleet and
the transit fleet. Emissions data is summarized in Table 1
and Figure 3.
City of Iowa City municipal activities generated 44,194
metric tonnes CO2e in 2015, or roughly 4.5% of the
Iowa City community’s total for the year. Since 2000,
emissions from municipal operations have dropped
54.5%, in large part due to capturing and flaring
methane at the Iowa City Landfill beginning in 2001.
Since 2005, emissions have dropped 15.5%, even with
increases in energy use and waste production. Increased
energy use has been offset by efficiency improvement
projects and increased renewable energy production.
Emissions dropped 21.0% between 2008 and 2015 due
to increased renewable energy production and reduced
energy use (Table 1; Figure 3).
The City has not set specific reduction targets for
municipal operations, so placeholder reduction targets
have been set to match goals made for the Iowa
City community and the Paris Agreement. Municipal
operations generated an estimated 52,304 metric tonnes
CO2e in the baseline year of 2005. Municipal operations
emissions will need to amount to 37,659 metric tonnes
CO2e (or less) per year in 2025 to meet a 28% reduction
goal, and to amount to 10,461 metric tonnes CO2e (or
less) per year in 2050 to meet an 80% reduction goal
(Figure 3).
* 2002 and 2005 emissions estimated based on average annual emissions change from 2000 to 2008 combined
with the reduction in solid waste emissions that began in May 2001.
Figure 3. Municipal Operations Emissions and Reduction Targets (2000-2015)
Municipal Greenhouse Gas Inventory
6 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Emissions by Source
The Iowa City municipal GHG inventory breaks down
emissions sources into seven categories:
Landfill Carbon Dioxide (CO2)
Waste generates methane, which when captured
and flared is converted to CO2
Electricity
Emissions generated by electricity used in
municipal operations
Diesel, Gasoline, & Ethanol
Emissions from burning fuels for the vehicle
fleet, transit fleet, and backup generators
Natural Gas
Emissions generated by burning natural gas in
city facilities, primarily for heating
Nitrous Oxide (N2O)
Primarily emissions generated from wastewater
operations, but small amounts also generated by
the burning of fossil fuels
Methane (CH4)
Primarily emissions generated by wastewater
treatment operations, but small amounts are
also generated by the burning of fossil fuels
Propane
Emissions generated by burning propane
(heating, forklifts)
Breaking municipal emissions down by emission source,
landfill CO2 accounts for 54.0% of total emissions in
2015. Electricity use accounts for 26.4% of the total,
followed by fuels at 9.5%, natural gas at 7.3%, nitrous
oxide at 2.5%, and propane and methane with less than
1% each (Table 2; Figure 4).
Municipal Greenhouse Gas Inventory
CO2e Emissions (metric tonnes)
Sector 2000 2002* 2005* 2008 2015
Solid Waste 72,053 21,470* 22,054* 22,638 24,001
Wastewater Treatment 7,042 7,741* 8,789* 9,837 6,621
Buildings and Facilities 6,779 7,765* 9,245* 10,724 5,426
Water Treatment 4,077 4,381* 4,836* 5,291 2,523
Vehicle Fleet 2,445 2,519* 2,629* 2,739 2,209
Transit Fleet 1,524 1,598* 1,708* 1,819 1,976
Streetlights and Traffic Signals 3,064 2,974* 2,839* 2,704 1,314
Airport Facilities 189 195* 205* 214 124
Totals: 97,173 48,642* 52,304* 55,966 44,194
* 2002 and 2005 emissions estimated based on average annual emissions change from 2000 to 2008 combined
with the reduction in solid waste emissions that began in May 2001.
Table 1. Municipal CO2e Emissions by Sector and Year
Figure 4. 2015 Municipal Operations CO2e Emissions by Source
23,845
54.0% 11,656
26.4%
4,185
9.5%
3,213
7.3%
1,107
2.5%
131
0.3% 57
0.1%
2015 Municipal Operations Emissions by Source
(metric tonnes CO2e)
Landfill Carbon Dioxide
Electricity
Diesel, Gasoline, & Ethanol
Natural Gas
Nitrous Oxide
Methane
Propane
23,845
54.0% 11,656
26.4%
4,185
9.5%
3,213
7.3%
1,107
2.5%
131
0.3% 57
0.1%
2015 Municipal Operations Emissions by Source
(metric tonnes CO2e)
Landfill Carbon Dioxide
Electricity
Diesel, Gasoline, & Ethanol
Natural Gas
Nitrous Oxide
Methane
Propane
7Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
The Iowa City vehicle and transit fleets run on a variety of fuel types, and emitted a total of 4,185 metric tonnes CO2e
in 2015. Off-road vehicles refer to heavy duty machinery (such as dump trucks, garbage trucks, landfill equipment,
etc.). Vehicles running on gasoline are fueled with a 10% ethanol blend (E10).
Breaking down emissions by fuel type, diesel for on-road vehicles accounted for 66.2% of all vehicle greenhouse
emissions, with off-road diesel accounting for 17.4%. Gasoline and ethanol for on-road and off-road vehicles combined
comprise 16.3% of the total (Table 3).
Emissions by Sector
The Iowa City municipal GHG inventory breaks down city operations into eight sectors:
Solid Waste
Iowa City Landfill facilities, operations, and emissions from waste
Wastewater Treatment
Wastewater treatment, lift stations, sanitary sewers
Buildings and Facilities
All buildings and facilities not under another sector
Water Treatment
Water treatment and distribution
Vehicle Fleet
Vehicles used for City of Iowa City activities (except Transit)
Transit Fleet
Vehicles used by Iowa City Transit including buses and other vehicles
Streetlights and Traffic Signals
Streetlights and traffic signals within city limits
Airport Facilities
Iowa City Municipal Airport buildings (does not include aircraft fuel use)
These sectors were defined in the first municipal inventory as divisions created within the software used to calculate
municipal emissions (CACP). To remain consistent and to compare across inventory years, these categories were
retained.
Municipal Greenhouse Gas Inventory
Source CO2e (Tonnes) % of Total
Landfill CO2 23,845 54.0%
Electricity 11,656 26.4%
Diesel, Gasoline, & Ethanol 4,185 9.5%
Natural Gas 3,213 7.3%
Nitrous Oxide 1,107 2.5%
Methane 131 0.3%
Propane 57 0.1%
Totals: 44,054 100%
Table 2. Municipal CO2e Emissions by Source
Table 3. Vehicle & Transit CO2e Emissions by Fuel Type
8 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Diesel, Gasoline, & Ethanol Breakdown:
Type CO2e (Tonnes) % of Total
Diesel 2,771 66.2%
Off road diesel 728 17.4%
Gasoline 621 14.8%
Ethanol 47 1.1%
Off road gasoline 18 0.4%
Fuel Totals 4,185 100%
Figure 5. 2015 Municipal Operations CO2e Emissions by Sector
Figure 6. Comparisons of per capita emissions with other Midwestern college towns
(data from reportingSTARcommunities.org/indicators and lawrenceks.org)
Annual Emissions Comparison by Sector
Since 2000, all sectors, except the transit fleet, have seen reductions in emissions. During this time period, the transit
fleet increased services to the public by operating more buses and increasing the number of routes. Solid waste has
seen the largest drop in emissions with a 66.7% reduction in emissions over the past 15 years, due to EPA requirements
to capture and flare methane created within the landfill.
Since 2008, all sectors, except solid waste and transit, have seen reductions in emissions. Wastewater treatment, water
treatment, buildings and facilities, streetlights and traffic signals, and airport facilities saw emissions reductions of 30%
or more from 2008 levels. Reductions in emissions since 2008 are due to a combination of increased renewable energy,
decreased energy use, and numerous energy efficiency improvement projects (Table 1; Figures 6 & 7).
2015 Emissions by Sector
Solid waste accounted for 54.3% of municipal operations’ GHG emissions in 2015. Unlike many local governments,
the City of Iowa City owns and operates the Iowa City Landfill, which services the entire Johnson County community.
Since the municipal analysis includes all City operations, waste-generated CO2 emissions for Iowa City, ten smaller
municipalities, and the rural community are included in this total. The population for Johnson County in 2015
was 139,436, nearly twice the size of Iowa City’s 2015 population of 74,220. For this reason, Iowa City’s municipal
operations waste emissions may be higher compared to other cities of similar size, as well as having a much higher
percentage in the municipal GHG inventory in comparison to the community-wide inventory.
Treatment of wastewater comprised the second largest source of GHG (15.0%), followed by energy use at buildings
and facilities (12.3%). Water treatment comprised 5.7% of the total. The Iowa City vehicle fleet emitted 5.0% of the
total, and Iowa City Transit fleet emitted 4.5%. Streetlights and traffic signals were 3.0% of emissions, and the Iowa City
Municipal Airport generated less than one percent of total emissions in 2015 (Table 1; Figure 5).
Municipal Greenhouse Gas Inventory
24,001
54.3%
6,621
15.0%
5,426
12.3%
2,523
5.7%
2,209
5.0%
1,976
4.5%
1,314
3.0%
124
0.3%
2015 Municipal Operations Emissions by Sector
(metric tonnes CO2e)
Solid Waste
Wastewater Treatment
Buildings and Facilities
Water Treatment
Vehicle Fleet
Transit Fleet
Streetlights & Traffic Signals
Airport Facilities
9Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Figure 7. Municipal Operations CO2e Emissions by Sector, without Solid Waste (2000, 2008, 2015)
Solid Waste Emissions
Emissions from the landfill dropped dramatically after capturing and flaring methane began in May 2001. Since 2001,
emissions have gradually increased as total waste placed in the landfill increases with increasing population in Iowa
City and Johnson County. In 2012, the shredded tire liner of a new landfill cell caught on fire. The emissions from the
burning of tires have not been quantified and are not included in these numbers. Note that emissions are calculated
based on the cumulative waste in place. Although annual landfill tonnages may decrease, GHG emissions may still
show an increase due to ongoing methane production from prior waste in place (Table 1; Figure 8).
Municipal Greenhouse Gas Inventory
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
CO2e (tonnes) Municipal Operations CO2e Emissions by Sector
(with Solid Waste)
2000 2008 2015
Figure 6. Municipal Operations CO2e Emissions by Sector, with Solid Waste (2000, 2008, 2015)
0
2,000
4,000
6,000
8,000
10,000
12,000
CO2e (tonnes) Municipal Operations CO2e Emissions by Sector
(without Solid Waste)
2000 2008 2015
10 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Waste placed in the landfill has varied between
110,000 and 150,000 tons per fiscal year during
the period of 2007-2015. Landfill tonnage
varies during this reporting period due to
several factors. The summer of 2008 flood
resulted in higher rates due to residential,
commercial and public building demolitions,
ruined household and property items, and used
sandbags. The local economy also influences
landfill tonnage per year. In a 2013 study, the
EPA found that for every $5,000 increase in GDP,
the tons of municipal solid waste increase by
approximately 130 lbs. (0.065 tons) per year.
Waste tonnage dropped in 2013, but has been
steadily increasing since then. Since 2015, five
new landfill initiatives have been passed by
City Council: curbside food waste collection, electronics waste ban, mandatory multi-family recycling, cardboard ban at
the landfill, and single stream recycling. Once in place, these initiatives are estimated to divert over 15,000 tons from
the landfill annually. It is estimated that by the end of 2018, landfill tonnage will decrease by about 15% due to the
implementation of these initiatives (Table 4; Figure 9).
Municipal Greenhouse Gas Inventory
2000
2002* 2005* 2008 2015
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
CO2e (tonnes) Iowa City Landfill CO2e Emissions
2000-2015
* 2002 and 2005 emissions estimated based on average annual emissions change from 2000 to 2008 combined with
the reduction in solid waste emissions that began in May 2001.
Figure 8. Solid Waste CO2e Emissions (2000-2015)
0
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
2007 2008 2009 2010 2011 2012 2013 2014 2015tonnes Iowa City Landfill Solid Waste per Fiscal Year
Figure 9. Solid Waste Tonnage per Year
Solid Waste per Year
Fiscal Year 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Tonnage 135,315 132,760 140,810 150,369 147,265 148,953 111,445 115,624 123,692 126,875
Table 4. Solid Waste Tonnage per Fiscal Year 11Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
2015 Energy Use
City energy use was measured in KWh, terms, and gallons and converted to MMBTUs for comparison purposes. In
2015, Iowa City municipal operations consumed a total of 207,169 MMBTUs (one million British thermal units 'BTU')
worth of energy. This figure includes electricity, vehicle fuels, natural gas, methane, and propane use. Buildings and
facilities consumed the most energy, at 62,873 MMBTUs, or 30.3% of the total. Wastewater facilities used the second
most (25.6%), followed by the vehicle and transit fleets (14.5% and 13.0%, respectively), water treatment facilities
(10.1%), streetlights and traffic signals (5.0%), and solid waste and airport facilities (less than 1% each).
The combined energy use of water and wastewater treatment consumed the most energy, at 35.7%, a larger
percentage than all other City buildings and facilities combined (30.3%); (Table 5; Figure 10).
Table 5. Municipal Energy Usage by Sector and Year
Energy Usage by Sector
62,873
30.3%
53,120
25.6%
30,140
14.5%
26,988
13.0%
20,834
10.1%
10,263
5.0%
1,674
0.8% 1,277
0.6%
2015 Municipal Operations Energy Use by Sector
(MMBTUs)
Buildings and Facilities
Wastewater Treatment
Vehicle Fleet
Transit Fleet
Water Treatment
Streetlights and Traffic Signals
Solid Waste
Airport Facilities
Figure 10. 2015 Municipal Operations Energy Usage by Sector
MMBTUs
Sector 2000 2008 2015
Buildings and Facilities 51,243 70,842 62,873
Wastewater Facilities 45,477 57,985 53,120
Vehicle Fleet 33,260 37,131 30,140
Transit Fleet 20,816 24,162 26,988
Water Treatment Facilities 18,940 25,440 20,834
Streetlights and Traffic Signals 12,515 11,157 10,263
Solid Waste 541 1,285 1,674
Airport Facilities 1,345 1,683 1,277
Totals: 184,137 229,685 207,169
12 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Annual Energy Use Comparison
Since 2000, total municipal energy use has increased 12.5%, from 184,137 MMBTUs to 207,169 MMBTUs. During
this time period, Iowa City’s population increased 12%. As Iowa City’s population increases, we can expect municipal
energy use to parallel this growth. Buildings and facilities, wastewater treatment, transit fleet, water treatment, and
solid waste facilities have all seen increases in energy use over the past 15 years. Decreases were seen in the vehicle
fleet, streetlights and traffic signals, and at the airport facilities.
Since 2008, energy use has decreased 9.8%, from 229,685 MMBTUs to 207,169 MMBTUs. All sectors, except for transit
and solid waste, have seen decreases in energy use since 2008. All sectors, except the vehicle and transit fleets, have
worked on significant efficiency improvement projects during this time (Table 5; Figure 11).
Energy usage varies year-to-year due to a variety of factors:
• Variations in weather
• Changes in demand for services
• Changes in wastewater and drinking water regulations
• Efficiency improvements (higher efficiency appliances and equipment)
• Changes in facilities operations by facilities managers
• Employee behaviors (turning off lights, running water, idling cars, etc.)
• Adoption of energy codes for new buildings
Energy Usage by Sector
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
Buildings and
Facilities
Wastewater
Treatment
Vehicle Fleet Transit Fleet Water
Treatment
Streetlights
and Traffic
Signals
Solid Waste
Facilities
Airport
FacilitiesMMBTU Municipal Operations - Energy Usage
2000 2008 2015
Figure 11. Municipal Operations Energy Usage by Sector (2000, 2008, 2015)
13Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Heating and Cooling Days
Variations in energy usage are partially attributable to variations in climate year-to-year. The annual sum of heating
degree days (HDD) and cooling degree days (CDD) provides an approximation of the energy required to heat and cool a
building during a year. Heating and cooling degree days are calculated by taking the difference between the mean daily
temperature and 65 degrees Fahrenheit (F). Daily temperature means above 65 degrees F are CDD, while daily means
below 65 degrees F are HDD. For example, if the average temperature on a given day was 45 degrees, that day had 20
HDD. The more total heating and cooling degree days there are in a year, the more energy is required to heat and cool
buildings. Typically, natural gas is used for heating on HDD, and electricity is used for cooling on CDD.
Iowa City’s total combined heating
and cooling degree days has varied
between just under 6,000 to nearly
8,500 per year during the period of
2000-2015. Heating degree days make
up the majority of degree days in Iowa
City. Average annual temperature
ranged from 47 degrees Fahrenheit to
54 degrees Fahrenheit over the same
period. In 2008, high energy usage
in buildings and facilities is partially
attributable to the high number of
heating degree days that year (7,659),
necessitating considerably more
heating energy (Table 6; Figure 12).
Energy Usage by Sector
40
42
44
46
48
50
52
54
56
58
60
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
Degrees (F) Degree Days Iowa City Annual Heating & Cooling Degree Days
2000-2015
Heating Degree Days Cooling Degree Days Total Degree Days Avg. Annual Temp
Figure 12. Annual Degree Days & Average Annual Temperature (2000-2015)
Year Avg. Annual Temp Heating Degree Days Cooling Degree Days Total Degree Days
2000 48 5249 622 5871
2001 50 6214 856 7070
2002 50 6308 940 7248
2003 49 6502 807 7309
2004 51 5864 662 6526
2005 52 5874 1303 7177
2006 53 5625 1074 6699
2007 51 6353 1087 7440
2008 48 7659 741 8400
2009 49 6536 597 7133
2010 51 6375 1158 7533
2011 51 6316 1092 7408
2012 54 5350 1257 6607
2013 49 6869 1064 7933
2014 47 7320 779 8099
2015 51 6027 934 6961
Table 6. Annual Heating and Cooling Degree Days (2000- 2015)14 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Vehicle and Transit Fuel Use
In 2015, the combined City vehicle and transit fleets
used 342,947 gallons of diesel, 79,887 gallons of gasohol
(E10, a blend of 10% ethanol and 90% gasoline), and
201 gallons of propane. Transit diesel fueled a fleet of
26 buses, each consuming an average of nearly 7,500
gallons of diesel in 2015. Diesel fueled roughly 130 fleet
vehicles, consisting of heavy-duty equipment and trucks,
while gasohol fueled roughly 150 fleet vehicles. Propane
fueled three forklifts (Table 7).
Energy Usage by Sector
2015 Transit & Fleet Fuel Use (gallons)
Sector Diesel Gasohol (E10) Propane
Transit 195,247 971 -
Fleet 147,700 78,915 201
Totals: 342,947 79,887 201
Table 7. 2015 Transit & Fleet Fuel Use
15Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
2015 Energy Costs
In 2015, Iowa City municipal operations total energy cost was $2,951,347. This figure includes electricity, vehicle fuels,
natural gas, and propane use. Buildings and facilities had the highest energy costs, at $751,004, or 25.4% of the total.
Wastewater treatment cost the second most (20.3%), followed by the vehicle fleet (14.6%), streetlights and traffic
signals (13.7%), transit fleet (12.6%), water treatment (11.6%), solid waste (1.1%), and airport facilities (less than 1%);
(Table 8; Figure 13).
Energy Costs by Sector
$751,004
25.4%
$598,019
20.3%
$430,043
14.6%
$405,009
13.7%
$372,339
12.6%
$342,455
11.6%
$31,009
1.1%
$21,469
0.7%
2015 Municipal Operations - Energy Cost by Sector
Buildings and Facilities
Wastewater Treatment
Vehicle Fleet
Streetlights and Traffic Signals
Transit Fleet
Water Treatment
Solid Waste Facilities
Airport Facilities
Figure 13. 2015 Municipal Operations Energy Cost by Sector
Energy Cost
Sector 2000 2008 2015
Buildings and Facilities $514,937 $981,753 $751,004
Wastewater Facilities $381,229 $752,408 $598,019
Vehicle Fleet $246,320 $678,213 $430,043
Streetlights and Traffic Signals $417,767 $411,329 $405,009
Transit Fleet $144,699 $593,033 $372,339
Water Treatment Facilities $257,103 $370,836 $342,455
Solid Waste Facilities $8,604 $28,232 $31,009
Airport Facilities $17,080 $24,229 $21,469
Totals: $1,987,739 $3,840,033 $2,951,347
Table 8. Municipal Energy Costs by Sector and Year
16 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Annual Energy Costs Comparison
Since 2000, municipal operations total energy costs have risen from $1,987,739 to $2,951,347, a 48.5% increase. Costs
have risen in all sectors except for streetlights and traffic signals, which have decreased in cost by 3.1%. Increases in
energy costs have outpaced increases in energy use since 2000.
Since 2008, municipal operations total energy costs have dropped $888,686, or 23.1%. All sectors saw decreases in
costs except solid waste facilities (Table 8; Figure 14).
Energy Costs by Sector
$0
$100,000
$200,000
$300,000
$400,000
$500,000
$600,000
$700,000
$800,000
$900,000
$1,000,000
Buildings and
Facilities
Wastewater
Treatment
Vehicle Fleet Streetlights
and Traffic
Signals
Transit Fleet Water
Treatment
Solid Waste
Facilities
Airport
Facilities
Municipal Operations - Energy Costs
2000 2008 2015
Figure 14. Municipal Operations Energy Cost by Sector (2000, 2008, 2015)
17Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
2015 Energy Costs and Usage by Source
Electricity accounted for the majority of energy costs in 2015, at 63.6% of the total, followed by diesel (22.5%), natural
gas (8.5%), gasohol (4.8%), and propane (0.7%); (Table 9; Figure 15).
Energy Costs by Source
$1,883,614
63.6%
$666,371
22.5%
$250,878
8.5%
$142,336
4.8%
$19,423
0.7%
2015 Energy Costs by Source
Electric
Diesel
Natural Gas
Gasahol
Propane
Figure 15. 2015 Energy Costs by Source
1
Shannon McMahon
From:Brenda Nations
Sent:Friday, August 18, 2017 4:37 PM
To:Shannon McMahon
Subject:graphs
Follow Up Flag:Follow up
Flag Status:Flagged
I can’t seem to find one of the graphs that Dylan redid so I will have to send you Table 3 (p. 8) to you on Monday.
This is Table 9 that goes on p. 18 and the only change I made was to add the word “Ave.”. If you can do that in your
software, it might be easier, but here it is:
Energy Source Usage Cost
Ave. Cost
per unit
Electric 25,999,570 kWh $1,883,614 $0.07
Natural Gas 604,009 Therm $250,878 $0.42
Diesel 344,774 gal $666,371 $1.93
Gasahol 79,887 gal $142,336 $1.78
Propane 11,992 gal $19,423 $1.62
Have a good weekend.
Brenda Nations
Sustainability Coordinator
City of Iowa City
410 E. Washington St.
Iowa City, IA 52240
Phone: (319) 887-6161
www.icgov.org/sustainability
Table 9. 2015 Municipal Energy Usage and Costs by Source
18 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Annual Energy Costs by Source Comparison
All energy sources rose in price over the period from 2000 to 2015, with the exception of natural gas. Natural gas prices
fluctuate year-to-year, with the average price in 2015 being roughly equivalent to costs in 2000. Fuel prices for gasoline
and diesel are roughly double their costs in 2000. The high energy costs in 2008 are attributable to a combination of
high energy prices and high energy use (Table 10).
Energy costs vary year-to-year due to a number of variables:
• Market price for electricity and fuel
• Variations in climate
• Usage
Energy Costs by Source
Average Energy Cost per Unit by Year
Source 2000 2008 2015
Electricity (per kWh) $0.05 $0.05 $0.07
Natural Gas (per ccf) $0.42 $0.81 $0.42
Gasohol (E10) (per gallon) $0.97 $2.28 $1.78
Diesel (per gallon) $0.88 $3.02 $1.93
Table 10. Average Energy Cost per Unit (2000, 2008, 2015)
19Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
In 2015, Iowa City municipal operations accounted for just 4.5% (44,194 metric tonnes CO2e) of the Iowa City
Community’s total GHG emissions (987,735 metric tonnes CO2e). Note that this is an imperfect comparison, as this
municipal GHG inventory includes landfill emissions for waste from all Johnson County residents, while the community
inventory only includes emissions from waste produced by residents in Iowa City. Although we can work towards
lowering local government emissions, collaboration with the community to lower community-wide waste emissions
will be essential for Iowa City to reach emissions reduction goals (Table 11; Figure 16).
Comparison to Iowa City Community
44,194
987,735
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
City Operations Community
(total)CO2e (tonnes) 2015 Iowa City CO2e Emissions
Comparison
City
Operations
4.5%
Community
95.5%
2015 Iowa City Emissions Comparison
City Operations vs. Community
2015
Sector CO2e (tonnes) Percent of Total
City Operations 44,194 4.5%
Community 943,541 95.5%
Community (total) 987,735 100%
Figure 16. 2015 Municipal Operations and Community CO2e Emissions Comparison
Table 11. 2015 Community Emissions Comparison
20 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Population Projections
Iowa City’s population has been steadily increasing, and Census projections anticipate that the population will continue
to increase; necessitating increased municipal services in the future. Increased services will, without increased
efficiency, require greater energy usage and cause potentially higher GHG emissions (Table 12; Figure 17).
Projections
Table 12. Iowa City Population Growth & Projection (2000-2050)
Year Population
2000 62,220
2005 65,641
2006 66,085
2007 66,529
2008 66,974
2009 67,418
2010 67,862
2011 69,094
2012 70,133
2013 71,591
2014 73,415
2015 74,220
2020 77,970
2025 80,700
2030 84,450
2035 88,200
2040 91,950
2045 95,700
2050 99,450
50,000
60,000
70,000
80,000
90,000
100,000
110,000
2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Iowa City Population Projection
2000-2050
Linear projection based on average growth between 2000, 2010, and 2014 Census figures
Figure 17. Iowa City Population Growth & Projection (2000-2050)21Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Electricity Emissions Projection
MidAmerican Energy produced just over two-thirds of Iowa City’s municipal operations electricity in 2015 and has
been increasing renewable wind energy production since 2004. Prior to 2015, the majority of the carbon emission
reductions had been sold as carbon credits; meaning that entities could purchase the carbon credits to perceptually
(but artificially) offset their carbon emissions. Due to this, Iowa City municipal operations could not claim the lowered
emissions from the wind and renewable generation until 2015.
In 2015, 35.5% of MidAmerican’s electricity in Iowa was generated using renewable wind energy. Going forward,
MidAmerican Energy projects 89% of its electricity production to be renewable by 2019, and 100% to be renewable
sometime after 2019. Current projections set 2025 as the goal for 100% renewable energy generation, but this date is
not currently finalized and subject to change. For more information on MidAmerican’s renewable energy goals, visit
their website at www.midamericanenergy.com/our-renewable-energy-vision.aspx.
Eastern Iowa Light and Power (EILP) provided just under a third of the local government’s purchased electricity in 2015,
and 98.5% of the electricity provided by EILP is used for wastewater treatment. While 60% of EILP’s energy sources
were carbon-free in 2015, EILP sold a large portion of its emissions reductions as carbon credits. While EILP plans
to add solar and wind installments over the next few years, it currently projects its overall carbon-free generation
percentage to remain steady at 60% through 2031.
The projected increase in MidAmerican Energy’s renewable energy production will drastically reduce municipal
emissions from electricity use. Compared to a scenario with no renewable electricity production, municipal operations
will produce roughly 10,500 fewer metric tonnes CO2e per year by 2019 (assuming electricity usage and the ratio
of electricity generated by MidAmerican and EILP remains constant at 2015 levels). If MidAmerican’s electricity
generation becomes 100% renewable by 2025, municipal operations will produce 12,000 fewer metric tonnes CO2e per
year when compared to a scenario with no renewable generation. All remaining emissions from electricity use would
come from electricity generated by EILP (Figure 18).
Projections
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
18,000
20,000
MidAmerican Percent Renewable Energy Generation CO2e (tonnes) Projected Municipal Electricity CO2e Emissions
Projected Emissions Emissions Without Renewables MidAm Renewable Energy PercentagePrevented GHG Emissions Based on MidAmerican Energy projections for percent renewable energy generation, assumes electricity use remains
constant at 2015 levels and EILP always provides 32% of municipal electricity.
Figure 18. Projected CO2e Electricity Emissions with Increasing Renewable Energy (2005-2025)22 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Municipal Operations
2025 Total Emissions
Projection
Provided MidAmerican becomes 100%
renewable by 2025, municipal operations
would be on track to reduce total
emissions by 30% from 2005 levels in 2025
(assuming other emissions sources follow
2015 trends). This reduction would exceed
the goal of a 28% reduction from 2005
levels, but more effort will be needed
to reach the goal of an 80% emissions
reduction by 2050. This allows the
opportunity to focus efforts in the areas
of natural gas usage, fleet and transit
vehicles, and landfill gas to energy options
(Figure 19).
Projections
2005 Baseline
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
CO2e (tonnes) Projected Municipal Operations GHG Emisisons
2005-2025
Projected Emissions 2005 Baseline 2025 Goal 2050 Goal
28% Reduction
80% Reduction
Figure 19. Projected Municipal CO2e Emissions (2005-2025)
63.1% 14.0%
11.0%
8.5%
2.9% 0.3% 0.2%
2019 Projected Municipal CO2e Emissions by Source
Landfill CO2
Electricity
Diesel, Gasoline, & Ethanol
Natural Gas
Nitrous Oxide
Methane
Propane
Figure 20. Projected Municipal Operations CO2e Emissions by Source in 2019
23Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Projected Municipal
Operations Emissions
by Source
(2019 & 2025)
With MidAmerican Energy’s increase
to 89% renewable electricity in 2019,
electricity GHG emissions will drop
from 26.4% to 14.0% of total municipal
emissions (assuming other emissions
sources follow 2015 trends). CO2
generated by waste at the Iowa City
Landfill will increase from 54.0% to
63.1% of the total. Total municipal
emissions will have dropped roughly
28% from 2005 levels (Figure 20).
If MidAmerican becomes 100% renewable by 2025, electricity emissions will drop to 10.9% of the toal, reducing annual
emissions from 2005 levels by roughly 30% (assuming other emission sources follow 2015 trends). Landfill CO2 will
produce nearly two-thirds of all municipal emissions (Figure 21).
Projections
Figure 21. Projected Municipal Operations CO2e Emissions by Source with 100% Renewable Energy
65.3%
11.4%
10.9%
8.8%
3.0% 0.4% 0.2%
2025 Projected Municipal CO2e Emissions by Source
Landfill CO2
Diesel, Gasoline, & Ethanol
Electricity
Natural Gas
Nitrous Oxide
Methane
Propane
24 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Water Division
• Replacement of eight variable frequency drives
with more efficient up-to-date technology at four
ground storage reservoirs and four collector wells
• Right-sized motor and pump and variable frequency
drives in Collector Well #1
• Right-sized motor and pump in Silurian Well #2
• Lighting replacements to LED (ongoing)
• Creation of wellhead protection areas and
establishing 370 acres of prairie and timber to
protect water resources and reduce mowing
• Construct bike path to improve pedestrian and
bicycle access to Water Plant
• Wind feasibility study (in 2002, DNR and HR Green
documented not feasible)
• Proposed: Future distribution growth study which
may allow reduce pumping costs
Streets Division
• Traffic signals converted to LED
• Ongoing LED replacement of City-owned
streetlights
• Contract to replace MidAmerican-owned
streetlights over 10-year period
• Proposed: Improved traffic signal coordination,
actuated traffic signals (installing vehicle detection)
Transportation Services
• LED lighting in all six City parking ramps
• ZipCar car share program
• Bongo-Bus on the Go bus location system
• Bike Share program (in progress)
• Electric vehicle (EV) charging station installations (in
progress)
• Two EV charging stations in Harrison Street Ramp
• Proposed: Route optimization study for transit
buses
• Proposed: Exploration of CNG or hybrid/electric
buses (may be cost prohibitive)
• Proposed: Explore solutions to Iowa Avenue railroad
bridge height challenge. It is too low for energy
efficient buses and most routes access UI Hospitals
Parks and Recreation
• Efficient lighting replacements at Mercer Aquatic
and Robert A. Lee Recreation Centers
• VFD motors with higher efficiencies installed at
Mercer Aquatic pool
Completed, Ongoing and
Future Emissions Reduction
Projects by Department
Public Works
• Proposed: A new Public Works Facility which would
establish a central location for City fleet vehicles,
would increase route efficiencies, decrease driving
time and mileage, and eliminate the storage of
vehicles in numerous locations; the new buildings
would also be built to higher efficiency standards
than the current facilities
Equipment Division
• One hybrid vehicle, three electric trucks
• Proposed: Modern technology vehicle telematics
system implementation to track idle times, usage,
route optimization
Landfill Division
• Capturing and flaring methane generated at the
landfill
• Wind feasibility study (in 2002, DNR and HR Green
documented not feasible)
• LEED certified building: East Side Recycling Center
Education Building (Platinum) with geothermal unit,
no natural gas usage, only electricity (which is largely
renewable)
• Solar and wind pilot installations at East Side
Recycling Center
• EPA “Food too Good to Waste” Pilot
• Recently approved recycling initiatives: mandatory
multi-family recycling, cardboard ban, electronic
waste ban, curbside food waste collection and single
stream recycling
Wastewater Division
• Biogas used to replace a portion of natural gas in
digesters
• Wind feasibility study (in 2002, DNR and HR Green
documented not feasible)
• High efficiency aeration blowers installed
• Efficient lighting replacements
• Two electric golf carts (uses three electric trucks,
listed under Equipment)
• Proposed: Explore cost benefit of heat recovery from
boiler exhaust stack
Reducing Emissions
25Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Neighborhood and Development Services
Building Inspection
• Energy code inspections
• Tracking city-wide building stock (energy use per
square footage)
Metropolitan Planning Organization
• Long Range Transportation Plan
• Bike Master Plan
Housing Authority
• Blower door energy audits and utility and water
efficiency installments on 91 public housing units
Sustainability Services
• Revolving loan fund from energy cost saving to
continue energy retrofits
• Administer City’s energy and climate grant
programs
• Completion of municipal GHG inventories
• Tracking of energy usage in municipal operations
• Proposed: Formalized plan for municipal operations
reductions
Airport
• Converted exterior halogen/mercury based lights to
LED lighting.
• Installed LED lighting in New Parallel Taxiway
• LED lighting added to South Apron Taxiway
• Ongoing replacement of incandescent lights in
T-hangar buildings with LED lighting
• Proposed: Convert HID style lighting in hangar
buildings to LED lighting
• Big Belly solar trash compactors installed in
Downtown Iowa City
• Contract to design Building Automation System
(BAS) for three facilities to detect program
efficiencies
• Energy audit for Terry Trueblood Recreation Area
Park Lodge
• Installation of energy efficient boiler and HVAC
systems at Mercer Aquatic Center
• Replacement of propane tank at H2O building at
Terry Trueblood Recreation Area with natural gas
line for improved efficiency
• Installed digital regulating values for Robert A. Lee
Recreation Center and Mercer Aquatic Center pools
for more efficient temperature regulation
• Replaced Robert A. Lee Recreation Center boilers
with high efficiency boilers
• Small installation of solar used to circulate pond
water at Thornberry Dog Park
Fire
• LEED certified buildings Fire Station #2 (Gold) and
Fire Station #4 (Gold) which use geothermal heat
sources for heating and cooling
Police
• Geothermal heat sources for heating and cooling at
the Iowa City Animal Care and Adoption Center
Library
• New bookmobile was designed with solar panel to
help charge the batteries and cut down on generator
use at stops
• HID lighting replacement with LED lights
• New recycling contract with alley waste pickup
service eliminates driving to deliver recycling to
remote sites
Senior Center
• High efficiency boiler replacement
• Roof replacement to white reflective roof
• Digital control of mechanical systems
• Proposed: Window treatment project to increase
energy efficiency
Reducing Emissions
26 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Organic material, such as food waste,
cardboard, and paper, generate the
majority of a landfill’s GHGs
Expand recycling availability and capability
Reduces waste placed in the landfill,
reducing emissions. Enables re-use of
materials, reducing their overall carbon
footprint
Expand reuse and repair options in the
community
Reduces short lifespans of items that would
otherwise end up in the landfill
3. Increase efficiency in the treatment of wastewater
and drinking water.
Maximize the use of biogas in the wastewater
digester for offsetting natural gas or electricity
use. It should be noted that due to industry
in town, the large amount of siloxanes in
biogas make it harder to make wastewater gas
useable, and may not be cost effective
4. Invest in and require a more efficient vehicle and
transit fleet. Potential options to reduce vehicle and
transit emissions include:
Reduce mileage
Fewer miles driven reduce GHG emissions.
Efficient driving techniques, reducing idling
time, and optimizing routes to destinations
can reduce GHG emissions
Transition to high efficiency, hybrid, and electric
vehicles
As old vehicles go out of service, replace
with high mile per gallon vehicles. If
feasible, replace with electric vehicles
Electric vehicles will emit very few GHG
emissions as Iowa City’s electricity becomes
increasingly carbon-free. Grant funding
from the State may be available
Explore feasible options to increase
efficiencies in diesel operated vehicles or
options to convert to CNG (compressed
natural gas) or RNG (renewable natural gas)
5. Reducing natural gas use, currently the fourth
largest source of municipal emissions provides
another potential avenue to reduce GHG emissions.
Increased building heating efficiency would reduce
energy usage, as would replacing current natural
gas systems with alternatives, such as electric
furnaces or geothermal.
Emissions Reduction
Background Information
As MidAmerican works towards 100% renewable
energy generation, the majority of electricity
consumed by municipal operations will be carbon-
free. Electricity GHG emissions will come almost
entirely from electricity purchased from EILP, which
services the wastewater treatment plant, the animal
shelter, and a few smaller facilities in the southern
portion of Iowa City.
Regulations in Iowa prevent net metering,
preventing solar panel installations from selling
excess energy production back to the grid.
Additionally, solar only operates during daylight
hours when the sun is shining, and might only
produce 25-30% of a building’s energy needs.
MidAmerican will be increasing costs for customers
with solar installations in order to account for
infrastructure needs when solar is not producing
electricity.
Emissions reduction plans will need to focus on
other areas in order to see any long-term emissions
reductions.
Potential Municipal Emission
Reduction Projects
1. Set municipal GHG emission reduction goals, identify
measures to undertake to reach those goals, and
monitor progress on a regular basis.
2. The Iowa City Landfill, with the largest share of
municipal GHG emissions, is a critical aspect to
reducing emissions. Potential options to reduce
landfill CO2 include:
Landfill gas to energy project
Convert captured landfill methane to energy.
Two opportunities to convert landfill gas
to energy have been considered in recent
years, a collaboration with the University
of Iowa and with the company Fiberight.
Neither option turned out to be feasible.
Other options may be complicated and
expensive, and landfill gas contains siloxanes
which must be removed to be useable
Increased organic material waste diversion
Reducing Emissions
27Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
• Consider energy efficiency policies for
community buildings and residences, i.e. when
sold
• Energy efficiency policies for employee
behaviors
• Waste policies (consider a zero waste plan)
• Update antiquated BAS, HVAC and boiler
equipment in City facilities with efficient
systems that meet the current Energy Code
• Update all lighting to LEDs
• All new purchased equipment should be Energy
Star rated or energy efficient
• Increase tree canopy, particularly for heat
island implications
• Continue to increase building efficiencies (for
energy and cost savings )
• Explore district energy using heat from
wastewater pipes in the Riverfront Crossings or
other districts
• Explore other additional options not listed here
After considering possible municipal opportunities,
staff can prioritize implementing strategies that are
reasonable and financially feasible. It will also be
necessary to accurately calculate GHG reduction
scenarios for any proposed projects or action in
order to meet future targets.
4. Incorporate recommendations into a community-
wide action plan, and include specific projects the
City and community plan to undertake to reduce
GHG emissions. The creation of an action plan
specific to municipal operations may also be useful.
5. Commit to updating the municipal GHG inventory
at least every five years or less to monitor results.
1. A realistic target reduction percentage should
be identified and a target year chosen in which
the reduction target should be achieved. Target
reductions for community and city government do
not have to be the same. Local governments have
control over all of their operations which create
emissions, and local governments can choose to
have a higher target reduction percentage. Local
governments therefore may be able to initiate,
publicize, and lead the community by example
in these endeavors. ICLEI, the State and Federal
government all recommend 80% emissions
reductions by the year 2050. Small incremental
reductions over a shorter time period are necessary
to reach this goal.
2. Work with staff, consultant, the Climate Action and
Adaptation Steering Committee, and the public in
parallel with community-wide mitigation plan to
identify municipal reduction strategies.
3. Review possible opportunities to undertake at a
municipal level:
• Explore landfill gas to energy project
• Explore wastewater gas potential
• Consider additional waste and recycling
initiatives
• Review renewable fleet and transit options
• Benchmark City facility energy use annually and
set targets to reduce energy intensity in local
government building stock
• Increase sub-metering to facilities that will
collect better information on energy and water
use
• Consider energy and water consumption in new
or retrofitted investments
• Evaluate feasibility of web-based interface that
provides the local government energy data to
the public
• Consider fleet idle policy, use location devices,
and driving practices to reduce usage
• Adopt alternative fuel guidelines or targets
• Reduce water usage within City facilities
• Insure all City facilities have recycling and
composting opportunities
• Look into possible building code policies for new
buildings
Next Steps
28 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
community behavior can impact global emissions
through consumption. Consumption-based inventories
are becoming more mainstream as cities want a
better understanding of economic consumption and
emissions which are created from consumable items
and materials.
With direct control over less than 5% of the
community’s GHG emissions, cooperative partnerships
will be needed to make a significant impact on
emissions. Cooperation with the University of Iowa,
residents, local industries, businesses, and local
government will be necessary to make community-
wide GHG reductions. Reducing emissions from waste,
vehicles, and wastewater would provide the greatest
effect. The City Council has appointed a Climate
Action and Adaptation Steering Committee to work
towards identifying and prioritizing specific actions for
community-wide reductions. The Steering Committee,
assisted by a consultant hired by the City, will be
soliciting input from the public to develop an action
plan to achieve the community-wide goals, whereas
City staff will be involved in creating a plan to reach
goals for City operations.
In closing, this quote is a reminder of the importance of
this work in our community to ensure quality of life for
future Iowa City residents:
“Continued emissions of greenhouse gases will cause
further warming and changes in all components of the
climate system. Limiting climate change will require
substantial and sustained reductions of greenhouse gas
emissions.”
— Intergovernmental Panel on Climate Change, Fifth
Assessment Report, 2013
Several decades of climate research has concluded that
human activities are changing our climate. The impact of
climate change within Iowa was summarized by the Iowa
Climate Change Advisory Council (Iowa Greenhouse
Gas Inventory & Reference Case Projections 1990-2025,
October 2008). Effects of climate change in Iowa include
increased frequency of extreme storms, floods, higher
rates of soil erosion, and damage to the economy,
ecosystems, and human health. These effects have
been linked to the rise of GHG emissions due to human
activities. The reduction of GHG emissions is a serious
and pressing matter since the U.S. is one of the largest
emitters per capita in the world, averaging about 20
metric tonnes of GHG per capita per year. Annual world-
wide average emissions are 4 metric tonnes per capita
and the estimated sustainable annual limit is 2 metric
tonnes per person.
In 2015, the City of Iowa City government operations
activities totaled 44,194 metric tonnes CO2e, or 4.5%
of the community total of 987,735 metric tonnes
CO2e. These amounts were calculated using the Local
Government Operations Protocol.
Using the estimated baseline of 2005, analysis was done
for government operations for the most recent year that
data was available (2015). Municipal emissions dropped
15.5% over the past ten years. MidAmerican Energy’s
transition to wind energy production is significant in
driving the reduction in emissions for Iowa City. Based
on MidAmerican projections for renewable energy
production, Iowa City municipal operations are on
track to narrowly meet the goal of 26-28% emissions
reduction by 2025. Reducing emissions 80% by 2050,
however, will require measures beyond reducing
emissions from electricity use. Further steps can be
taken to move forward on the process to reduce these
emissions, which can have positive effects on the local
and global environment and economy.
In addition to this inventory, a consumption-based
inventory for the Iowa City community will be completed
by the fall of 2017. The consumption-based inventory
will include additional emissions due to food and
materials consumed in the community. Iowa City was
awarded grant funding from the Urban Sustainability
Directors Network (USDN) for a pilot project to complete
this work, which will give additional insight into how
Conclusion
29Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Municipal Facilities Energy Use, Emissions, and Cost by Site
Appendix 1
Metric
Use Tonnes Use Tonnes Tonnes Emissions
Sector (therms)CO2 (kWh)CO2 Total CO 2 % of Total CO2 Total Cost
Wastewater Treatment 228,199 1,214 8,877,886 4,170 5,384 36.2%598,019$
Water Treatment 19,397 103 5,536,062 2,419 2,523 17.0%342,455$
Streetlights - - 2,723,917 1,190 1,190 8.0%368,655$
Mercer 115,597 615 1,069,920 468 1,083 7.3%111,459$
Library 33,957 181 1,538,400 672 853 5.7%118,366$
Parking Ramps 26,125 139 1,550,914 678 817 5.5%120,472$
City Hall 30,341 161 1,169,040 511 672 4.5%90,298$
Rec Center 45,872 244 481,920 211 455 3.1%56,679$
Parks 9,686 52 551,695 243 294 2.0%64,162$
Senior Center 18,580 99 381,120 167 265 1.8%38,876$
City Transit 20,055 107 225,997 99 205 1.4%51,386$
Fire Stations 5,780 31 327,833 143 174 1.2%27,014$
Streets 19,350 103 95,885 42 145 1.0%20,535$
Equipment 11,281 60 197,023 86 146 1.0%6,649$
Other Sites 4,736 25 229,236 100 125 0.8%21,549$
Airport 5,285 28 219,361 96 124 0.8%21,469$
Traffic Signals - - 283,228 124 124 0.8%36,354$
Refuse 8,754 47 156,460 68 115 0.8%5,098$
Landfill - - 225,430 99 99 0.7%16,536$
Animal Shelter - - 66,662 32 32 0.2%7,434$
East Side Recycling Center - - 63,295 28 28 0.2%5,377$
Cemetery 1,014 5 18,488 8 13 0.1%2,984$
Weather Siren - - 9,798 4 4 0.0%2,837$
Totals:604,009 3,213 25,999,570 11,656 14,869 100.0%2,134,660$
2015 Municipal Facilities Natural Gas and Electricity Use and Emissions
*Data is for facilities only
**Electricity CO 2 emissions calculated using 2015 MidAmerican & EILP emission factors
***Does not include fuel use for backup generators
ElectricityNatural Gas
30 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
2015 Emissions Factors
Appendix 2
CO2 CH4 N2O Total CO 2e
kg /kWh 0.4822 0.003 0.0029 Average emission factor for national electricity grid National emissions factor database
lb /kWh 9.58E-01 1.78E-02 2.63E-02 9.65E-01 MidAmerican MidAmerican
lb /kWh 1.04E+00 1.78E-02 2.63E-02 1.04E+00 EILP MidAmerican
g /VMT 4.32E+02 2.78E-02 2.94E-02 4.40E+02 19.64 lbs CO2/gal &20.386mi/gal eia.gov
kg /Person 0.00E+00 4.45E-02 2.55E-02 8.00E+00 Iowa City South WWTP Iowa City South WWTP
kg /scf/yr 0.00E+00 2.37E-06 0.00E+00 6.62E-05 Landfill Landfill
lb /hr 3.49E+01 0.00E+00 0.00E+00 3.49E+01 34.85 lbs/h for small gas engines (lawnmowers
&lawncare)eia.gov
kg /hr 6.09E+01 0.00E+00 0.00E+00 6.09E+01 2.68kg/L for large diesel engines eia.gov
kg /L 2.68E+00 0.00E+00 0.00E+00 2.68E+00 2.68kg/L for large diesel engines eia.gov
Description SourceEmission FactorUnits
31Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
¹ Values take from Climate Change 2013: The Physical Science Basis.
Contribution of Working Group I to the Fifth Assessment Report of the
Intergovernmental Panel on Climate Change, 2013 (AR5)
² Not taken into account in this inventory
Appendix 3
Common Name
Chemical
Formula
Global Warming
Potential
(100-yr) 1
Carbon dioxide CO2 1
Methane CH4 28
Nitrous oxide N20 265
Sulfur hexaflouride 2 SF6 23,500
Hydrofluorocarbons 2 Various Varies
Perfluorocarbons 2 Various Varies
32 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Global Warming Potentials
Definitions
ADT Average Daily Traffic count: the total volume of traffic past a single point over a 24-hour period.
BAU Business as usual scenario: assumes no strategies are employed to reduce GHGs.
Biogas The gas produced from decomposition of landfill waste or sewage consisting of methane, carbon
dioxide, nitrogen and other trace gases such as hydrogen sulfide, ammonia and hydrogen.
CACP2009 2009 Clean Air and Climate Protection software supplied by ICLEI, used by Iowa City to calculate
past years municipal GHG emissions inventories. Municipal categories are grouped according to this
software, which most U.S. cities used for consistency in reporting.
CH4 Methane: A hydrocarbon that is a greenhouse gas with a global warming potential 28 times that of
carbon dioxide (CO2). Methane is produced through anaerobic (without oxygen) decomposition of
waste in landfills, the treatment of wastewater, animal digestion, decomposition of animal wastes,
production and distribution of natural gas and petroleum, coal production, and incomplete fossil fuel
combustion.
CO2 Carbon Dioxide: A naturally occurring gas, and also a by-product of burning fossil fuels, methane, and
biomass, as well as land-use changes and other industrial processes. It is the principal anthropogenic
GHG.
CO2e Carbon Dioxide Equivalent: A measure of the global warming potential of greenhouse gases emitted
including CH4, N2O and other gasses in relation to CO2.
A consumption-based inventory refers to an emissions inventory that in addition to traditional
emissions created within the city limits, evaluates emissions associated with all consumption,
regardless of where it is produced. Many local governments are pursuing this type of inventory to
better understand how food and other materials purchased and consumed by the community or
municipality have an impact on the environment and economy.
GHG Greenhouse gas: Absorbs and emits thermal radiation in the atmosphere and cause the greenhouse
effect. Examples include water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O),
hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6), and many others.
Only CO2, CH4, and N2O were considered in this report.
GPC Global Protocol for Community-scale Greenhouse Gas Emissions Inventories: The first global standard
to measure GHG emissions from cities created as a joint project by ICLEI-Local Governments for
Sustainability, the World Resources Institute (WRI) and C40 Cities Climate Leadership Group, with
additional collaboration by the World Band, UNEP, and UN-Habitat.
GWP Global Warming Potential: The GWP-weighted emissions of direct GHGs in the inventory are presented
in terms of equivalent emissions of carbon dioxide (CO2). GWP factors represent the ratio of the heat-
trapping ability of each GHG relative to that of carbon dioxide over a 100-year period.
Appendix 4
33Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Consumption-
Based
inventory
Appendix 4
HFCs Hydroflorocarbons: Compounds containing only hydrogen, fluorine, and carbon atoms. They were
introduced as alternatives to ozone depleting substances in serving many industrial, commercial,
and personal needs. HFCs are emitted as by-products of industrial processes and are also used in
manufacturing. They do not significantly deplete the stratospheric ozone layer, but they are powerful
greenhouse gases with global warming potentials ranging from 140 to 11,700 times that of carbon
dioxide by weight.
IPCC The Intergovernmental Panel on Climate Change: The leading body for the assessment of climate
change, established by the United Nations Environment Programme (UNEP) and the World
Meteorological Organization (WMO) to provide the world with a clear scientific view on the current
state of climate change and its potential environmental and socio-economic consequences. (www.
ipcc.ch/)
ICLEI Local Governments for Sustainability: An international non-profit organization providing software and
assistance for communities to calculate their emissions. ICLEI was formerly known as International
Council for Local Environmental Initiatives. (www.icleiusa.org/)
KWh Kilowatt hour, a unit of electricity use.
LED Lights Light-emitting diode lights: A high efficiency lighting technology that reduces lighting energy
consumption by as much as 80% compared to traditional incandescent lighting. The City of Iowa City
has employed this technology in a retrofit of the City’s traffic lights, street lights, and facility lighting, to
reduce consumption of fossil fuel derived energy.
LGOP Local Government Operations Protocol: Guidelines designed to provide a standardized set of
procedures for local governments to quantify and report GHG emissions associated with their
government operations. Developed by the California Air Resources Board, the California Climate Action
Registry, ICLEI, and the Climate Registry. Used by the City of Iowa City to report municipal emissions.
MMTBTU One million British Thermal Units, or 10 therms. A unit of energy measurement.
Metric Tonne One thousand kilograms, or approximately 2,205 U.S. lbs.
Natural Gas Gases consisting of 50 to 90 percent methane (CH4) and small amounts of heavier gaseous
hydrocarbon compounds such as propane (C3H8) and butane (C4H10). Most prevalent fuel used for
home and water heating in Iowa City. Some natural gas in the U.S. is recovered from underground
using the process of “fracking.”
N2O Nitrous Oxide: A powerful GHG with a 100-year global warming potential of 265 times that of
carbon dioxide (CO2). Sources of nitrous oxide include soil cultivation practices, especially the use
of commercial and organic fertilizers, wastewater treatment, fossil fuel combustion, nitric acid
production, and biomass burning.
34 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Appendix 4
PFCs Perfluorocarbons: A group of human-made chemicals composed of carbon and fluorine only.
These chemicals (predominantly CF4 and C2F6) were introduced as alternatives, along with
hydrofluorocarbons, to the ozone depleting substances. In addition, PFCs are emitted as by-products
of industrial processes and are also used in manufacturing. PFCs do not harm the stratospheric ozone
layer, but they are powerful greenhouse gases with global warming potentials ranging from 5,700 to
11,900 times that of carbon dioxide.
Scope 1 Emissions being released within the city limits resulting from combustion of fossil fuels and from waste
decomposition in the landfill and wastewater treatment plant.
Scope 2 Emissions produced outside city limits but are induced by consumption of electrical energy within the
city limits.
Scope 3 Emissions of potential policy relevance to local government operations that can be measured and
reported but do not qualify as Scope 1 or 2. This includes, but is not limited to, outsourced operations,
employee commutes, and emissions from purchased goods.
SF6 Sulfur hexafluoride: A very powerful GHG used primarily in electrical transmission and distribution
systems and as a dielectric in electronics. The 100-year global warming potential is roughly 23,500
times that of carbon.
Therm A unit of measure for energy that is equivalent to 100,000 British Thermal units, or roughly the energy
in 100 cubic feet of natural gas. Often used for measuring natural gas usage for billing purposes.
VMT Vehicle Miles Traveled: A unit used to measure vehicle travel made by private vehicles, including
passenger vehicles, truck, vans and motorcycles. Each mile traveled is counted as one vehicle mile
regardless of the number of persons in the vehicle.
35Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017
Summary of Iowa City’s STAR Rating
Appendix 5
36 Iowa City Municipal Greenhouse Gas Emissions Inventory Update - August 2017