Montreal’s Methane Problem: From Snow Dumps to Landfills

A dirty little secret.

STARTER STATS

• Anthropogenic methane accounts for 60% of total methane emissions (Global Methane Assessment, 2021).

• Primary anthropogenic sources: agriculture (40%), fossil fuel (35%), and waste (20%)

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McGill University researchers have found that Montreal’s largest snow dump, along with inactive landfills and aging natural gas infrastructure, are among the city’s top methane polluters.

Methane, despite being less abundant than carbon dioxide, has been found to be ~32 times as impactful in the atmosphere, making these emissions particularly important to study.

More than 3,000 hotspots were identified during a four-year mobile monitoring survey. Unexpectedly, the snow dump at Francon Quarry emits methane levels comparable to active and former landfills, partly due to melting snow creating lakes that foster methane-producing microbes. The highest methane concentrations were concentrated in the city’s east end, where older infrastructure leads to more natural gas leaks, amplified by population density.

“Though there's much less methane than carbon dioxide (CO2) in the atmosphere, every methane molecule will warm the planet by about 32 times as much as every CO2 molecule. We need to know where these emissions are coming from to resolve them.”

— Dr. Peter Douglas, McGill University

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