Earth is like a greenhouse, with the atmosphere serving as its shell, explains Kuljeet Grewal, an assistant professor at the University of Prince Edward Island’s Faculty of Sustainable Design Engineering. Grewal shared insights on the greenhouse gas effect and its significant impacts during a recent interview.
“It is very similar to the greenhouse we use to grow things. When the sun heats it, it traps the heat, and if people enter their greenhouse, it would be warm,” said Grewal. This analogy reflects the mechanism by which our planet retains heat; as greenhouse gas emissions rise, more heat becomes trapped within the atmosphere.
While the greenhouse gas effect is necessary to maintain Earth's temperature, excessive accumulation contributes to global warming. Grewal elaborated, stating, “When the sun is heating the Earth, then at night, when the heat is emitting to the atmosphere, some of it is being trapped by gases.” The dilemma occurs when the balance is disrupted, resulting in temperature spikes.
Grewal identifies several major contributors to greenhouse gas emissions on Prince Edward Island, such as energy production, livestock farming, deforestation, and transportation. About 24% of P.E.I.'s emissions stem from agriculture, primarily through livestock and crop production, with methane being the major greenhouse gas produced by cattle.
“Transportation is the biggest contributor to P.E.I. emitting greenhouse gases, responsible for 42% of total greenhouse gas emissions,” Grewal noted, with passenger cars and trucks accounting for 71% of these emissions. Buildings contribute 19%, manufacturing 11%, and the waste sector adds another 4% to the overall emissions.
Climate change is not just about rising temperatures; it is also altering weather patterns. Grewal pointed out, “Due to increased emissions, we have more severe weather events like heat waves, heavy rainfall, storms.” Such extreme weather conditions are becoming increasingly common due to the heightened greenhouse effect.
Despite not all greenhouse gases posing risks to the ozone layer, some compounds, like chlorofluorocarbons (CFCs), are notorious for their damaging effects. Grewal explained how these chemicals, often used in aerosols and refrigerants, degrade ozone molecules and thin the protective layer of the stratosphere.
The Montreal Protocol, established to phase out production and consumption of ozone-depleting substances, plays a pivotal role in combating climate change. Grewal highlighted its importance, stating, “The Montreal Protocol aims to phase out the production and consumption of ozone-depleting substances such as CFCs.” He also emphasized how the treaty has been ratified by all countries and is expected to prevent significant global temperature rise.
According to government forecasts, 2025 is projected to be warmer than any year prior to 2023, with global mean temperatures at least 1°C above pre-industrial levels. Last year was reported as the hottest on record globally, with temperatures surpassing the 1.5°C threshold above pre-industrial levels, which aligns with targets set by the Paris Agreement on climate change.
Did you know? Heavy fuel oil generates three kilograms of greenhouse gas per litre, compared to propane, which emits 1.5 kilograms per litre. These statistics indicate the significant environmental cost of relying on fossil fuels.
Despite these challenges, P.E.I. is making strides toward meeting its climate goals. The province is currently on track to achieve 75% of its 2030 greenhouse gas emissions target. Grewal’s insights underline the necessity of continuing our commitment to reducing greenhouse gas emissions as the climate crisis intensifies.