Sustainability

D. Washoe County Community-wide GHG methodology

GHGs Three greenhouse gases are included in this inventory: carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Many charts in this report represent emissions in “carbon dioxide equivalent” (CO₂e) values, calculated using the Global Warming Potentials for methane and nitrous oxide from the IPCC 6th Assessment Report. Global Warming Potentials (GWPs) are the warming effect of an emission of 1kg of each gas relative to that of CO2.

US Community Protocol Washoe County used the ClearPath Climate Planner tool to calculate 2021 community-wide GHG emissions. ClearPath is produced and supported by the non-profit ICLEI, “Local Governments for Sustainability.” Washoe County also used earlier of versions of Clearpath for its 2008 and 2014 inventories. See 2008 and 2014 inventory summary results in Appendix 5.

The 2021 inventory follows the U.S. Community Protocol for Accounting and Reporting of Greenhouse Gas Emissions, Version 1.2, published July 2019, which aligns with the Global Protocol for Community-Scale Greenhouse Gas (GHG) Inventories. As local governments continue to join the climate protection movement, the need for a standardized approach to quantify GHG emissions is essential. The US Community Protocol (USCP) represents a national standard in guidance to help U.S. local governments develop effective community GHG emissions inventories. It establishes reporting requirements for all community GHG emissions inventories, provides detailed accounting guidance for quantifying GHG emissions associated with a range of emission sources and community activities, and provides a number of optional reporting frameworks to help local governments customize their community GHG emissions inventory reports based on their local goals and capacities.

Boundary The community “boundary” includes the entirety of Washoe County: Reno, Sparks, and Unincorporated Washoe County. Data from the total population of Washoe County is included in this inventory, as has been the case for previous inventories.

Baseline year Washoe County has established a “baseline year” of 2021. This means that the County’s GHG reduction goals of 28 percent by 2025, 45 percent by 2030, and Net Zero 2050 will be measured in comparison to the data in this inventory. Per the Paris Agreement, 2005 is typically recommended as the baseline year for measuring emissions reductions. However, data collection and GHG collection methodology has vastly improved over the past 20 years, so Washoe County is baselining against 2021 instead.

Government Operations Emissions Inventory Washoe County has also conducted a detailed County Operations GHG Inventory for 2021. The government operations inventory is a subset of the community, as shown in Figure 3. For example, data on commercial energy use by the community include energy consumed by municipal buildings, and community vehicle-miles-traveled estimates include miles driven by municipal fleet vehicles.

Figure 3: Relationship of Community and Government Operations Inventories

Sources and Activities

Communities contribute to greenhouse gas emissions in many ways. Two central categorizations of emissions are used in the community inventory: 1) GHG emissions that are produced by “sources” located within the community boundary, and 2) GHG emissions produced as a consequence of community “activities.”

By reporting on both GHG emissions sources and activities, local governments can develop and promote a deeper understanding of GHG emissions associated with their communities. A purely source‐based emissions inventory could be summed to estimate total emissions released within the community’s jurisdictional boundary. In contrast, a purely activity‐based emissions inventory could provide perspective on the efficiency of the community, even when the associated emissions occur outside the jurisdictional boundary. The division of emissions into sources and activities replaces the scopes framework (Scope 1, 2, and 3) that is used in government operations inventories, but that does not have a clear definition for application to community inventories.

Input Data for this Inventory Local utility operators provided data to Washoe County for this analysis, and the list of these specialists and their agencies are listed in Appendix 1. Some other data comes from federal databases from, for example, the Environmental Protection Agency (EPA), or other agencies. Data sources are listed in sector descriptions.

Quantification Methods

GHG emissions can be quantified in two ways:

1. Measurement-based methodologies refer to the direct measurement of GHG emissions (from a monitoring system) emitted from a flue of a power plant, wastewater treatment plant, landfill, or industrial facility.
2. Calculation-based methodologies calculate emissions using activity data and emission factors. To calculate emissions accordingly, the basic equation below is used:

Activity Data x Emission Factor = Emissions

Most emissions sources in this inventory are quantified using calculation-based methodologies. Activity data refers to the relevant measurement of energy use or other GHG-generating processes such as fuel consumption by fuel type, metered annual electricity consumption, and annual vehicle miles traveled.

Known emission factors are used to convert energy usage or other activity data into associated quantities of emissions. Emissions factors are usually expressed in terms of emissions per unit of activity data (e.g. lbs CO2/kWh of electricity). For this inventory, calculations were made using ICLEI’s ClearPath Climate Planner tool.

Emissions generating activities

In ClearPath, the five basic emissions generating activities are included in the analysis:

1. Use of Electricity by the community Power plant emissions associated with generating electricity used within the jurisdictional boundary of the community, regardless of the location of the electricity generation facility.
2. Use of Fuel in Residential and Commercial Stationary Combustion Equipment Combustion emissions associated with fuels used in residential and commercial stationary applications (e.g., natural gas used in boilers and furnaces) within the jurisdictional boundary of the community, excluding fuels used for production of electricity or district energy.
3. On-Road Passenger and Freight Motor Vehicle Travel Emissions associated with transportation fuels used by on-road passenger and freight motor vehicles.
4. Use of Energy in Potable Water and Wastewater Treatment and Distribution Emissions associated with energy used in the treatment and delivery of potable water used in the community and in the collection and treatment of wastewater used in the community, regardless of the location of the water and wastewater infrastructure.
5. Generation of Solid Waste by the Community End-of-life emissions (i.e., projected future methane emissions) associated with disposal of waste generated by members of the community during the analysis year, regardless of disposal location or method.

The community inventory also includes:

• Wastewater treatment processes
• Off-road, rail, and aviation travel
• Process & fugitive emissions from natural gas distribution

The table below lists the Required, Recommended, and Optional Community-wide Inventory inputs from the US Community Protocol. The following sections have detailed descriptions of Washoe County community operations by sector as well as explanations of the methodology for calculating GHGs for each activity.