Researchers at McGill University have found that methane emissions are unevenly distributed across Montreal.<\/p>\n
Over 3,000 methane hotspots were found by researchers over a four-year monitoring program, where it was discovered that Montreal\u2019s east end saw the highest concentrations of methane.<\/p>\n
One of the worst polluters was the city\u2019s largest snow dump, which researchers say emits methane at levels comparable to the city\u2019s current and former landfills, and natural gas leaks.<\/p>\n
\u201cThough there\u2019s 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\u00a0molecule,\u201d said\u00a0Peter Douglas<\/a>, Associate Professor in the\u00a0Department of Earth and Planetary Sciences<\/a>\u00a0and study co-author. \u201cWe need to know where these emissions are coming from to resolve them.\u201d<\/p>\n Behind the study<\/p>\n Montreal, like many cities, only publishes estimated emission statistics according to McGill University. This led them to use mobile monitoring to try and determine more accurate information.<\/p>\n The study was carried out over four years \u2014 2019, 2022-24 \u2014 over 3,300 square kilometres of Montreal, and some off-island sites like the Saint-Sophie landfill.<\/p>\n Researchers were able to collect air samples with a device that measures carbon dioxide and methane levels every second.<\/p>\n What was found was that inactive landfills were among the biggest polluters, alongside the Francon Quarry \u2014 site of Montreal\u2019s largest snow dump.<\/p>\n \u201cIt\u2019s as large as some of the other landfills. A ton of stuff is dumped there, stuff that\u2019s picked up off the roads,\u201d Douglas said. As the snow melts, it creates a lake that potentially harbours microbes capable of releasing additional methane.<\/p>\n Additionally, researchers found that more gas leaks happen in the east end, which also raised emission levels.<\/p>\n \u201cMost gas leaks are concentrated where we use this older infrastructure,\u201d said Douglas. \u201cBut we really focused on population density. With more people, there are more natural gas lines and more leaks.\u201d<\/p>\n The researchers looked at three specific areas over ten weeks, which allowed them to learn how methane emissions changed over time, revealing which hotspots were persistent and which were more short-lived.<\/p>\n \u201cWe\u2019d see an increase in concentration and then it would come back down, so we could figure out approximately how much gas was coming from that source and locate where it was, especially when we had wind data to help us triangulate the location,\u201d Douglas said.<\/p>\n McGill University will continue to monitor methane emissions to see how levels change during different seasons.<\/p>\n