John Gyakum didn’t set the timetable for his Climate and Climate Change – ATOC 183 course, but the fact that 500+ students enrolled in the class this semester, speaks volumes about its popularity.
It’s being held on Fridays from 4 to 7 p.m.
Each time Gyakum, a renowned professor in the Department of Atmospheric and Oceanic Sciences, teaches this course, enrolment rises sharply.
Launched in 2024, the course explores the science of climate and climate change. It’s open to students across the University, and Gyakum aims to make topics such as radiation and energy balance accessible since many enrolled students don’t have a background in physics or high-level mathematics.
“My goal is to really inform students from all Faculties of the factual basis for climate change so that they understand some of the scientific details that will allow them to make intelligent decisions in the future, whether they be policymakers or whatever field of work they might choose to go into,” he says.
The course tackles a different aspect of climate change each week, including its impact, the carbon cycle, and mitigation policies.
“The students have an opportunity in this class to identify what they can do as individuals and collectively to influence policies and so forth,” Gyakum says.
He points out an interesting fact that may surprise many of them: water vapour is the most important greenhouse gas. “One of the reasons why water vapour is not heavily publicized is that we don’t have a whole lot of direct control over emitting water vapour, the way we do over carbon dioxide and methane,” he says.
“Global warming is driven by fossil fuel emissions. Water vapour’s importance is its positive feedback on warming the climate, which helps keep the planet habitable for humans. However, as warming occurs, water vapour also increases, further warming the climate,” explains Gyakum. Moreover, increases in water vapour boost the likelihood of more extreme weather events, specifically extreme rainfalls.
The study of water vapour is closely related to Gyakum’s research on extreme weather, and how it can modulate the climate. (Gyakum helped coin the meteorological term ‘bomb cyclone’ for fierce storms that rapidly intensify, accompanied by a sharp drop in atmospheric pressure.)
“My goal is to really inform students from all Faculties of the factual basis for climate change so that they understand some of the scientific details that will allow them to make intelligent decisions in the future.”
Professor John Gyakum
In the course, Gyakum also touches on how the oceanic temperatures in the tropics have markedly increased with climate change. “That actually has an influence on us, even in the wintertime,” he says, referring to atmospheric rivers. “These are transports of tropical air masses into much higher latitudes, even into areas as far north as the Arctic, such as Inuvik near the Beaufort Sea.”
These tropical air masses are often responsible for some of Montreal’s most extreme weather, he says, including the 1998 ice storm that hobbled Quebec’s hydro-electric grid and left millions in the dark.
In 2025, the Faculty of Science honoured Gyakum with the Leo Yaffe Award for Excellence in Teaching as “an exceptionally talented and gifted educator.”
He teaches the climate course in Leacock 132, the same cavernous lecture hall where he and colleague Professor John Stix have taught a popular natural disasters course for 25+ years. Gyakum says he has learned a lot about delivering a course in that space. “Normally students dread going into that classroom because it can be rather impersonal with over 500 students.”
He won’t spend the entire three-hour class lecturing. He’ll mix things up, with students answering poll questions and completing pop-type quizzes (although not for marks). They will likely hear from guest speakers, academics with expertise in specific aspects of climate change. One speaker last year talked about the effect of heat stress and its impact on human health, says Gyakum, noting that Europe has been experiencing unprecedented summer heat waves.
Discussion items are also on the agenda and students can weigh in via a cube device that circulates around the lecture hall. “It’s kind of like a beach ball,” Gyakum says. “It’s heavily padded and there’s a microphone embedded inside of it so that the student can actually talk into this cube from the back of the room and everybody can hear them, and it’s also recorded. You can just throw it around and students can comment and provide insight.”
