British Columbia equivalency with federal methane regulations: emissions reduction estimation

As part of the Pan-Canadian Framework on Clean Growth and Climate Change, the Government of Canada reaffirmed its commitment to reduce methane emissions from the oil and gas sector by 40 to 45 percent from 2012 levels by 2025. Methane is a potent greenhouse gas (GHG) that is at least 25 times more powerful than carbon dioxide and methane emissions make up about 15 percent of Canada’s total GHG emissions. The oil and gas sector is the largest contributor to methane emissions in Canada.

In April 2018, Environment and Climate Change Canada (ECCC) published the federal methane regulations to deliver on this commitment. The Regulatory Impact Analysis Statement (RIAS) assessed the impacts of the regulations, including methane (in CO₂e) emissions reduction estimates.^{Footnote 1} This analysis used emissions projections as reported in Canada’s 2016 Greenhouse Gas Emissions Reference Case. ECCC has since updated its emissions reduction estimates to reflect departmental projections, as reported in Canada’s 3rd Biennial Report to the United Nations Framework Convention on Climate Change (UNFCCC).^{Footnote 2} A summary of the emissions estimation methodology and the resulting emission reduction estimates follows below.

Emissions estimation methodology

The analysis estimated emission reductions by first developing detailed engineering emissions estimates for the baseline and regulatory scenarios, and then scaling these to the Department’s overall emission estimates for the oil and gas sector in order to ensure that the estimates are consistent.

To calculate venting and fugitive gas reductions, baseline and regulatory emission factors for the various standards and product types were multiplied by the total number of devices or facilities for the respective standard. This procedure calculates the total amount of gas that will be emitted with and without the Regulations. The difference between the emissions in the baseline scenario and the emissions in the regulatory scenario were used to estimate the incremental reductions.

The sources for the emission factors differ for each standard

• For facility production venting requirements, provincial data on facility venting and flaring volumes were used to estimate the baseline emissions, and compared to the required reductions as per the regulations
• For LDAR, the emission factors derived from the Clearstone Engineering emission factor study^{Footnote 3}, and modified using a method described in the EPA Protocol for Equipment Leak Emission Estimates^{Footnote 4} 
• For pneumatic devices, emission factors were developed from an engineering assessment of pneumatic devices undertaken in British Columbia in 2013;^{Footnote 5} and
• For compressors, the emission factors for the reciprocating compressors are estimated using a dataset from Target Emission Services. For centrifugal compressors, the emission factors are obtained from an engineering assessment of compressors undertaken in 2014 by the U.S. EPA.^{Footnote 6}

To determine emissions of the various pollutants contained in emitted gases, the composition of gas streams is determined using estimates of gas composition from the Clearstone Engineering report,^{Footnote 7} with the exception of gas from facility production venting, as these composition ratios were obtained from a combination of reports from provinces.^{Footnote 8} To obtain the amounts of CO₂, CH₄ or VOCs reduced, the natural gas reductions are multiplied by the composition ratios for each standard which are provided in Table 1.

The engineering emission estimates were then scaled to align with the departmental baseline emissions forecasts. The departmental baseline emission projections for the oil and gas sector are determined using the production forecast of oil and gas from the NEB, in combination with the national inventory report. These departmental projections are developed in the Energy, Emissions and Economy Model for Canada (E3MC), one of the Department’s models for estimating methane (in CO₂e) emission trends and regulatory impacts in Canada.

The engineering estimates were used to derive a baseline for all fugitive and venting emissions, which was calculated for five sectors; natural gas production, natural gas processing, and light oil mining. These baseline estimates were then compared to the departmental baseline emissions forecast for sectors to obtain a set of ratios, or scaling factors, as follows:

These scaling factors were then applied to the engineering reduction estimates for each pollutant and for estimates of conserved gas to derive final incremental estimates for the regulations.

Emission reductions estimates

For the purposes of determining equivalent outcomes between the BC and federal regulations, the Department has estimated the methane (in CO₂e) reductions achieved by the BC regulations using the same methodology. The updated baseline emissions estimates and updated reduction estimates for the province of British Columbia, in addition to reductions estimates under the BC regulations are shown in Table 2.

Based on these estimates, the BC regulations result in cumulative emission reductions of 3.1 megatonnes of carbon dioxide-equivalent (Mt CO₂e) from 2020-2024, which exceeds the federal regulations, as summarized in Table 3.