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

Abstract

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.

Quantification of Methane Emissions from Cold Heavy Oil Production with Sand Extraction in Alberta and Saskatchewan, Canada

“…As shown in Figure , the site-level emission rates for CHOPS facilities in Alberta have decreased from 2018 to 2021, indicating regulatory impacts in mitigating CHOPS emissions in Alberta. However, despite regulatory efforts, results from the aerial surveys conducted in 2018, 2020, and 2021 showed no significant difference in emission rates in Saskatchewan. While Saskatchewan has declared to have met its 2025 reduction target based on inventory estimates, uncertain baselines, underreported emissions, decreased production, and lack of measurement data preclude a definitive conclusion regarding the efficacy of recent regulations. , Of particular concern is the potential for significant, often underestimated CH 4 emissions from CHOPS operations in Saskatchewan, , which may not have received adequate attention during the implementations of CH 4 reduction regulations.…”

“…As with most other well types, casing pressure must be relieved to avoid restricting oil production and to avoid pushing the liquid column down to the point where gas enters the pump and leads to cavitation and motor failure . Thus, the potential sources of CH 4 emissions from a CHOPS facility includes the release of casing gas from an annular vent, engine shed vents, failing pneumatics, flashing losses, breathing losses from storage tanks, truck loading emissions as well as fugitive leakage including leaking connectors and valves. ,, Emissions can also arise from abandoned or suspended CHOPS wells. Casing gas can be utilized as fuel for the engine, and studies have reported that a large portion of total site emissions in Lloydminster was from sheds containing fuel gas engines. ,, …”

Highly Uncertain Methane Leakage from Oil and Gas Wells in Canada Despite Measurement and Reporting

“…We also tested the performance of Bridger Photonics’ Gas Mapping LiDAR, an aircraft-based remote sensing system that quantifies observed plume emissions. , The use of this technology has proliferated in Canada to quantify upstream oil and gas methane emissions ,,, and has been supported by federal and provincial Canadian governments. Using POD curves from Conrad et al (175-m altitude, 3-m/s wind speed), we found that only the largest 7% of emitters, representing 47% of methane emissions, are expected to be detected in Alberta (<2% of emitters and 44% of emissions in B.C.).…”

“…Simple calculations or infrequent measurement can lead to considerable uncertaintyand often underestimationfor many emission sources. While recent work has shed new light on emissions from on-site compressors, liquid storage tanks, and heavy oil production, − wellbore leakage remains understudied.…”

“…However, these reported data were not designed for methane emission estimation and are notably incomplete, , requiring governments to apply assumptions to derive methane emission estimates. , Interestingly, differing assumptions between governmental bodiesimplying different understandings about underlying mechanismshave led to methane estimates that fundamentally disagree in magnitude and trend despite being derived from the same data sets (Figure ). Recent measurement-based inventories suggest that such leakage represents ∼7% of upstream oil and gas methane in Canada. ,, …”