Directly Monitoring Landfill Methane Emissions: Nova Scotia’s Flux Lab Measured Emissions at Landfills Across Canada and Found Emissions Were Less Than Models Predicted in Some Regions Due to Seasonal Climate Variations

    

      Most countries that estimate landfill gas emissions do it by modeling the emissions based on the parameters available rather than directly measuring them. However, as emissions monitoring technologies get better, become more available, and get cheaper, it is now possible to measure them directly. Research groups have done just that, initiating landfill gas emissions assessments. One such research group, Flux Lab, based at St. Francis Xavier University in Nova Scotia, measured LF methane emissions across Canada, as shown in the map below. Flux Lab’s previous work was in oil & gas methane monitoring, where they honed their skills. In June, they published a peer-reviewed study in the journal Elementia: Science of the Anthropocene.

     The study includes 42 landfills. It was noted that predicted emissions often exceeded measured levels, particularly at sites in cold, arid environments. There were other discoveries as well that did not fit the models. A broad finding is that regional climate affects landfill methane generation.

     Waste Dive interviewed Flux Lab’s science lead, Dave Risk. Canada has variable climates and big seasonal climate differences. This gives LF gas emissions estimates a corresponding wide range. Canada has better data at the provincial level, but estimates more, resulting in wider ranges at the federal level.

     The measurements from the study are being used to develop federal LF methane policy. They previously did something similar for oil & gas methane emissions. He also said that estimations from modeling need to be updated.

     They utilized two truck-mounted detection and measurement systems in two parts of the country, and aircraft monitoring as well. They noted that one of their trucks was stolen, including the attachments. They found it later, abandoned, but with equipment stripped.

“Waste Dive: Carbon Mapper was also conducting its work using airborne measurements to identify fugitive landfill methane emissions around the time of this study. How should we think about your measurements and data in the context of those other attempts to calculate emissions?”

Risk: “I think that we’re seeing very much the same things, and that was very reassuring once we began comparing notes with Carbon Mapper.”

“That tells us there’s some basic things that are important. Like the work face is more important than we’ve been giving it credit for at most landfills. I think that’s a universal theme between our different studies. We do definitely see emissions across the gas-gathering system. Those emissions can sometimes even be higher, ironically, at sites that are actually producing RNG because they’re optimizing the landfill characteristics to produce gas. That’s creating issues, or it’s just not as fully captured as it could be.”

     Flux Lab’s study differed in its emphasis on climatic variations driving emissions variations. Their study also better explored landfills of different sizes.

“We found that some of those really small sites had quite low collection efficiencies, and it’s probably mostly down to the relative size of the work face versus the area with the waste stack and collection. They’re small, so they have a relatively large active face.”

     They tested their tools and did controlled emissions to validate their measurements. Truck-mounted measurements matched aircraft measurements. These things increased their confidence that their measurements were more accurate than the estimates of the IPCC model and other models.

     He notes that measurements were as estimated in much of the country, with the major exception of the cold, dry climates, where they were much lower than estimated. In those climates, he says, the models got the wrong decay constant. He also notes that Canada has a very high rate, about 95%, of what is known as ‘organics diversion,’ where organics like yard waste are diverted to compost facilities. That reduces measured emissions relative to estimates as well.

     The measurements were taken over a five-month period, mostly in the summer. That may offset the missing emissions in the cold, dry areas, which would be expected to be a little higher in winter.

“In Canada, where we have pretty severe winters in some areas, we really have the surface microbiological activity shutting off in the winter. We don’t have that oxidation potential that will remove methane in the winter time, so we can see that emissions can tick upward somewhat in the winter.”

     They hope to get a study going in the winter months in those areas to measure the seasonal variations.

     In the study, they note that challenges to measuring methane emissions include “changes in barometric pressure and wind speed, limited site accessibility, complex dispersion patterns caused by wind conditions, topography or obstacles, and the heterogeneous nature of landfill methane sources.”

     The following section from the paper’s conclusion explains the findings, their implications, and what the next steps should be.

“By integrating bias-corrected mobile survey measurements with inventory data, we demonstrated that Canada’s landfill methane inventory might be overstated—potentially by a factor of two. This suggests that methane mitigation targets could be more achievable than anticipated, especially if active work faces and other high-emitting sources were effectively managed. However, improving inventory accuracy requires measurement campaigns, not necessarily similar to the survey approach used in this exploratory study, at a selection of sites that reflect all the landscape and climatic conditions encountered in Canada, and better inventory data collection on landfill operations and waste composition to improve the input parameters of FOD models. Tracking emissions over an extended period at certain sites would provide valuable insights into how factors such as weather and operational changes affect emission variability. As Canada moves toward ambitious waste sector methane reduction targets, aligning mitigation strategies with measurement-informed inventories will be critical to success. Our study underscores how valuable empirical data can be for validating models and supporting the case for scaling up measurement-informed approaches—already pioneered in Canada’s oil and gas sector—to achieve similar transparency and effectiveness in waste management.”

 

 

References:

 

FluxLab’s ‘fast and furious’ campaign to measure Canada’s landfill emissions. Dave Risk discusses the research group’s latest study, which validated emerging understanding of the landfill conditions that lead to methane emissions. Jacob Wallace. Waste Dive. July 27, 2026. FluxLab’s ‘fast and furious’ campaign to measure Canada’s landfill emissions | Waste Dive

Canada’s landfill methane inventories: The challenge of accurate modeled and measurement-based emissions. Jordan Stuart, Evelise Bourlon, Rebecca Martino, Lindelwa Coyle, Susan Fraser, Emil Laurin, Felix Vogel, Nicholas Bishop, Sebastien Ars, and David Risk. Elementa: Science of the Anthropocene (2026) 14 (1): 00115. June 26, 2026. Canada’s landfill methane inventories: The challenge of accurate modeled and measurement-based emissions | Elementa: Science of the Anthropocene | University of California Press