Creating a greenhouse gas emissions inventory and forecast
A greenhouse gas inventory brings together data on community and municipal energy use and solid waste generation in order to estimate greenhouse gas (GHG) emissions in a given year. The forecast projects future emissions based on assumptions about population, economic growth and fuel mix.
The inventory can be used to document energy consumption and waste composition data, and to calculate the resulting greenhouse gas emissions.
An emissions inventory consists of:
- A community inventory: residential, institutional, commercial, industrial, transportation, and solid waste sectors.
- A corporate inventory: municipal government facilities and operations, including buildings, street lighting, water and wastewater treatment, municipal fleet, and corporate and/or community solid waste.
The greenhouse gas inventory is developed by collecting data on:
- Electricity and fossil fuel energy use;
- Transportation (such as vehicle kilometres travelled, fleet composition and fuel(s) consumed); and
- The quantity and composition of waste and disposal methods.
PCP recommends that municipalities choose the baseline year of 1994 or a year for which reliable data is available. The baseline year will serve as a basis for setting an emissions reduction target and act as a point of comparison for the future.
Greenhouse gases measured
The inventory tracks three principal greenhouse gases: carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), expressed as a CO2 equivalent (eCO2). Typically, these greenhouse gases are generated from:
- Burning fossil fuels to light, heat, cool and ventilate buildings, homes and offices, and to run municipal operations, industrial processes and vehicles; and
- Decomposing organic waste in landfills.
Why develop an inventory?
An inventory can be used as a management tool to:
- Save money: The inventory helps track dollars spent on energy. What can be measured can be managed. An inventory can reveal opportunities for investment in energy efficiency improvements.
- Provide valuable information: An emissions inventory is a useful first step in the development of a Local Action Plan. Identifying significant sources of GHG emissions will help a municipality implement appropriate emissions reduction measures and develop an effective Local Action Plan.
- Provide a valuable reference point: Selecting a baseline year, and completing an emissions inventory for that year, is essential to track reductions in GHG emissions.
- Participate in carbon trading: A verifiable greenhouse gas inventory is required before participating in the emerging carbon trading market.
Completing an inventory
An interdepartmental team should be formed to undertake and/or delegate the data collection tasks required to prepare an emissions inventory and forecast, and to develop and implement a Local Action Plan (see Milestones Three and Four). The team should include staff from all departments involved in the various sectors contained in the inventory.
The inventory can be completed by in-house staff, interns or outside consultants.
Requirements for Recognition
- In table form, summarize the municipality's corporate and community emissions in the base year and other inventory year(s), if available, and the emissions from municipal operations and the community by their respective sectors.
- List the emission coefficients in the body of the text or as an appendix to the plan.
- Using a table and/or chart, show the corporate (municipal operations) and community emissions forecast for 10 years past the year in which the municipal government committed to PCP. Include a brief discussion of how the forecast was derived. Include the base year and other inventory years, if any, and calculate the per cent change in each corporate and community sector. Explain why emissions decreased or increased in each sector according to any changes to municipal operations and the community that occurred between the two comparison years.