Canada

Methane emissions from Canada’s non-producing oil and gas wells appear to be seven times higher than government estimates, according to a new study led by researchers at McGill University. The findings spotlight a major gap in the country’s official greenhouse gas inventory and raise urgent questions about how methane leaks are monitored, reported and managed.

“Non-producing wells are one of the most uncertain sources of methane emissions in Canada,” said Mary Kang, Associate Professor of Civil Engineering at McGill and senior author on the paper. “We measured the highest methane emission rate from a non-producing oil and gas well ever reported in Canada.”

Methane is a potent greenhouse gas. Over a 20-year period, it traps about 80 times more heat in the atmosphere than the same amount of carbon dioxide. It’s also associated with air pollution and health risks.Kang’s team directly measured methane emissions from 494 wells across five provinces using a chamber-based method and analyzed well-level data such as age, depth and plugging status. The national emissions estimate they arrived at – 230 kilotonnes per year – is sevenfold higher than the 34 kilotonnes reported in Canada’s National Inventory Report. The study was published in Environmental Science & Technology.