According to a new study by a leading Canadian researcher, the biggest sources of methane emissions from oil and gas sites are not the devices widely believed to be the main culprit.
The result is that Canada may underestimate its emissions of the potent greenhouse gas and overlook effective ways to meet its reduction targets, says Matthew Johnson, director of the Energy and Emissions Lab at Carleton University and co-author of the paper.
“This suggests it is time to rethink,” he told CBC News.
“Maybe we can be a little more efficient so that we don’t look for the things that matter.”
Research, which relied on laser technology mounted on an aircraft that flew over oil and gas reservoirs in British Columbia in 2019, estimates methane emissions to be 1.6 to 2.2 times higher than current federal estimates.
Methane, the main component of natural gas, is released from various systems in a production facility during oil and gas production. As a heat-storing greenhouse gas, it is around 70 times more effective than carbon dioxide, but only lasts in the atmosphere for around nine years. Canada’s goal is to cut methane emissions 40-45 percent below 2012 levels by 2025.
Reducing methane is seen as a way to get more immediate positive benefits in the fight against climate change, but Canada can only do so if it knows where the colorless and odorless gas is coming from.
Large methane sources are overlooked
The regulations in Canada are primarily based on surveys that gas optical cameras (OGI) use at oil and gas sites to identify sources of methane leaks. However, the study suggests that there is a “stark difference” between what the OGI surveys find and what the new airborne technology can see and “policies and regulations that rely solely on OGI surveys “risk missing a significant portion of the emissions”.
According to the study, more than half of methane emissions were attributed to storage tanks, reciprocating compressors, and unlit flares. Storage tanks, which alone were responsible for a quarter of methane emissions at oil and gas sites, proved to be a particularly worrying source of emissions.
These sources are harder to spot with OGI surveys because they are elevated and could be overlooked by a camera on the ground.
“So these three sources are usually very important,” said Johnson. “And if all of your inventory is based on camera work, then it makes sense why we keep seeing these persistent differences.”
Total emissions probably under counted
methane currently makes 13 percent of Canada’s total greenhouse gas emissions, based on official estimates, however several studies based on field measurements have shown that the actual amount of methane emitted is much higher. Until this new study, it was not known exactly which devices were causing this discrepancy.
Tom Green, a policy analyst at the David Suzuki Foundation in Vancouver, has been following the methane problem closely. He says the new study’s finding that methane emissions are likely to be much higher than official estimates is not surprising, but is still “alarming” given the potential climate impact.
“Right now we’re doing something pretty unfair, which is to report relatively low methane emissions to the United Nations,” said Green.
“For such a large country around the world, we should do much, much more about our position on natural gas exports and take a leadership role on this dossier.”
Green said a key issue is that current regulations place too much emphasis on checking for leaks in general rather than identifying more fundamental problems.
“If you can see that about a quarter of emissions are coming from tanks, it’s not a leak,” Green said.
“The tank is designed so that the methane can outgas. So that’s a design problem.”
Regulations under review
BC has set limits for tank leakage, but the study found tank leak rates much higher than the limits. Federal methane regulations, which back up provincial regulations, do not directly regulate leaks from compressors and unlit flares.
The study was carried out in collaboration with the British Columbia government, which has its own methane regulations along with Alberta and Saskatchewan. The federal government granted that the equivalence agreements of the three provinces to have their own regulations rather than the federal regulations imposing on them.
“The results of the new methane study require additional research and measurements to ensure we have the most accurate estimates of total emissions from the sector, and we continue to support these efforts,” the BC Department of Environment and Climate Change Strategy said in a statement.
The ministry said it will take the new information into account as it develops its detailed plan to meet its emissions targets for 2030, due to be released later this year.
In a statement to CBC News, Environment and Climate Change Canada admitted uncertainties in estimating methane emissions and said it was working to improve the methodology of its official estimates.
“ECCC will review the author’s research for relevance both to assessing existing regulations and developing new policy options to further reduce methane emissions from the oil and gas sector.”