The Futility of Relative Methane Reduction Targets in the Absence of Measurement-Based Inventories

• Published in: Environmental science & technology Vol. 57; no. 50; pp. 21092 - 21103
• Main Authors: Conrad, Bradley M., Tyner, David R., Johnson, Matthew R.
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 19.12.2023
• Subjects: Air Pollutants - analysis; Canada; Emission measurements; Emissions; Emitters; Energy and Climate; Inventories; Medical Futility; Methane; Methane - analysis; Natural Gas - analysis; Oil and gas industry; Reduction; Canada; Saskatchewan Canada; measurement-based inventory; methane inventory; oil and gas; methane emissions; mitigation targets; inventory projections; methane intensity; regulatory effectiveness
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/acs.est.3c07722

Under the Global Methane Pledge, Canada is developing oil and gas sector methane regulations targeting 75% reductions from 2012 levels by 2030. Without measured baselines and inventories, such policies are ultimately unverifiable and unenforceable. Using the major oil and gas producing province of Saskatchewan as a case study, we derive first-ever measurement-based methane inventories for the region and comprehensively model previous emissions back to the 2012 baseline. Although relative reductions of 23–69% have likely occurred, the dispersion of modeled possibilities and the high emissions from continuing production illustrate the limits of this approach as a meaningful policy metric. Moreover, nearly 90% of apparent reductions are explained by decreased production at heavy oil facilities, suggesting emissions have potential to rebound if production resumes. By contrast, derived measurement-based methane emissions intensities facilitate quantitative assessment and show that despite any past reductions, Saskatchewan’s 0.41 ± 0.03 g/MJ intensity remains among the highest in North America. This highlights how relative reduction targets absent measured baselines and inventories are inherently futile and risk rewarding high emitters while obscuring ongoing mitigation potential. Ultimately, required global methane reductions will only be achieved by adopting objectively and independently verifiable emission metrics while measuring and tracking progress toward a net zero future.