Sources and reliability of reported methane reductions from the oil and gas industry in Alberta, Canada

Abstract

Since committing to a 40%–45% reduction in methane emissions from the oil and gas industry in Canada by 2025, relative to 2012 levels, the federal government has reported significant emission reductions from the industry in its largest producing province, Alberta. At the same time, multiple measurement studies have shown that the industry’s emissions in Canada’s national greenhouse gas inventory are underreported, generally by a factor of 1.5 to 2. To better understand the source and reliability of claimed emission reductions, we developed an upstream oil and gas (UOG) methane emissions inventory model for the province of Alberta, 2011–2021, following government methodologies. The model revealed that historically only approximately 28% of Alberta’s UOG methane emissions are based on reported data, and although more comprehensive reporting was enforced in 2020, further analysis suggests that this reporting shift could represent a significant fraction of the apparent emission reductions since 2012. Reviewing the data and modeling assumptions underlying the inventory estimate revealed significant uncertainty in not only modeled emission sources but also in the operator-reported data. These findings imply that the reported emission trends since 2012 are highly uncertain, and even future emission factor updates might not improve the reliability in reported trends of emission reduction. This poses a significant problem for the validation of the stated 40%–45% reduction from 2012 levels. To improve the representativeness of both annual inventory magnitudes and the emission trends for the upstream sector in Alberta, we make recommendations to the Canadian federal and Alberta provincial governments.