Synergist - February 2010

and provinces also have separate mandatory reporting requirements for certain entities. The unit of measure for most protocols is the metric ton (MT) of carbon dioxide equivalent (CO2e) emissions.

The Canadian Department of the Environment has required reporting of emissions by facilities that emit greater than 100,000 MT per year of CO2e since 2005 (for 2004 emissions). Starting with 2009 GHG emissions, the threshold for reporting is 50,000 MT per year of CO2e. The province of Alberta also has specific GHG emissions reporting requirements.

The U.S. EPA issued a final Mandatory Reporting of Greenhouse Gases Rule on Sept. 22, 2009. This rule requires major emitters of GHG in the U.S. to collect and report data on an annual basis starting with their 2010 GHG emissions. The applicability to facilities is based on “source categories” and the quantity of GHG emissions from covered sources. Facilities in certain source categories, such as electricity generators, petroleum refineries and cement plants, must report regardless of the quantity of their emissions. For some other source categories, the threshold for reporting is 25,000 MT of CO2e. Additionally, EPA is moving ahead to regulate GHG emissions under the Clean Air Act (CAA).

Mandatory GHG reporting requirements also exist for major emitters, such as electrical utilities, in 18 states. California has some of the most stringent requirements for reporting and verifying GHG emissions. Depending on your industry and the locations of your facilities, you may need to consider these requirements as well.

Since these programs are evolving, periodically check the requirements to ensure that you have the most up-to-date information.

Many of the voluntary programs are for entity-wide reporting within specific geographic boundaries. Defining boundaries for entity-wide reporting can be complex if some facilities are partially owned by another company. In all cases, the basis for determining boundaries must be well documented.

Types of Emissions

Once the boundaries have been established, you must consider which types of GHG emissions you will report. Most protocols define GHGs as the six gases and categories of gases determined by the Kyoto Protocol (see Table 1). Combustion of fossil fuels is the most common source of greenhouse gases, but many other sources exist, including process and fugitive emissions from a wide variety of sources.

The impact on global warming of these gases varies and is accounted for through the use of a Global Warming Potential (GWP) factor. The GWP is used to determine the CO2e emissions. As shown in Table 1, carbon dioxide has a GWP of 1 while sulfur hexafluoride has a GWP of 23,900. Therefore, emitting 1 MT of SF6 is equivalent to emitting 23,900 MT of CO2. SF6 is commonly used in electricity transmission as well as some manufacturing processes.

The GHG Protocol categorizes GHG emissions into three “scopes”:

Scope 1: Direct GHG emissions from
sources such as stationary fuel combus-
tion (e.g., boilers, turbines), company-
owned vehicles, process emissions and
fugitive emissions (e.g., HFCs from re-
frigeration and air conditioning systems)

Emissions Sources

The best way for the EHS professional to identify potential emissions sources at a facility is to develop a clear understanding of the processes. Obtain a process flow diagram and identify potential emissions by interviewing site personnel who are knowledgeable of the process.

Table 1. Greenhouse Gas Global Warming Potential

Common Greenhouse Gases
Global Warming Potential (GWP)

Carbon Dioxide (CO2)

1

Reporting Boundaries

Once the purpose is established, the protocol for developing the GHG emissions inventory should become clear. The protocol helps establish the boundaries of reporting.

If mandatory reporting applies, then boundaries for reporting will typically be by facility—a fairly simple requirement for a single factory wholly owned by one company, but much more complicated for an industrial complex with multiple facilities operated by various entities.