Greenhouse gas (GHG) emissions from Canada’s buildings sector indicate improvement in 2022 in keeping with the general results of the newly released national inventory report. The 89 megatonnes of carbon dioxide equivalent (Mt CO2e) emanating from commercial, institutional and residential buildings accounted for 13 per cent of economy-wide GHG output and surpassed the buildings sector’s 85 Mt tally in 2005. However, it is a 5.3 per cent drop in annual emissions compared to 94 Mt in 2019.
That pre-pandemic year has been tapped as the most relevant benchmark for monitoring Canada’s progress toward its target to cut economy-wide GHG emissions to at least 40 per cent below 2005 levels by 2030. The latest data, which Canada is required to report under its commitment to the United Nations Framework Convention on Climate Change (UNFCC), shows a mere 7 per cent decrease (from 761 to 708 Mt) had been achieved eight years out from that deadline. Nevertheless, it’s a reversal of the upward emissions trajectory seen earlier last decade.
“We have bent the curve and emissions remain on a long-term downward track,” maintains Steven Guilbeault, Canada’s Minister of Environment and Climate Change.
That’s largely due to a nearly 60 per cent drop in emissions from electricity generation, tumbling from 117 to 47 Mt over 17 years. In 2005, electricity accounted for 15.4 per cent of economy-wide emissions versus just 6.7 per cent by 2022. In contrast, buildings now represent a larger share of the total than their 11.2 per cent quotient in 2005.
Among the five other economic sectors tracked: heavy industry and waste posted improvements; transport sits back at its starting level after first trending upwards; and, like buildings, agriculture and oil and gas have slipped farther behind. In 2022, oil and gas emitted 217 Mt of GHG for 31 per cent of the total — up from 195 Mt and 25.6 per cent of the economy-wide output in 2005. Even so, emissions from oil and gas have edged down since peaking at 228 Mt in 2018.
Growth factors into the pace and interpretation of progress. Canada gained about 6.7 million residents between 2005 and 2022, boosting the population by roughly 20 per cent. The emissions intensity of the economy, which measures GHGs per dollar of gross domestic product (GDP), declined by 30 per cent in the same period. Per capita emissions stood at 24 tonnes of CO2e in 2005 versus 18 tonnes of CO2e in 2022.
“The decline in emissions intensity can be attributed to factors such as fuel switching, increases in efficiency, the modernization of industrial processes and structural changes in the economy,” states the executive summary to the GHG inventory report.
Carbon dioxide represented 78 per cent of Canada’s GHG mix in 2022. Other components include: methane (CH4) at 17 per cent; nitrous oxide (N2O) at 4 per cent; and fractions of perfluorocarbons (PFCs), hydrofluorocarbons (HFCs), sulphur hexafluoride (SF6) and nitrogen trifluoride (NF3) making up the remainder. “Canada’s emissions profile is similar to most industrialized countries,” the report also notes.
Space and water heating, maintenance vehicles and equipment comprise major scope one sources
Within the buildings sector, the GHG inventory report provides a breakdown of direct, or scope one, GHG emissions with separate data for commercial/institutional and residential buildings. Meanwhile, other sectors and subcategories — notably, public electricity and heat production, transportation and mining/extracting, refining and manufacturing processes — cover the buildings sector’s scope two and three emissions.
On-site energy combustion for space and water heating accounts for the vast share of the buildings sector’s GHG output. In 2022, commercial/institutional buildings emitted 35 Mt and residential buildings emitted 39 Mt from this source. Residential emissions were down by 4 Mt from the 2005 output of 43 Mt, while commercial/institutional emissions were 3 Mt higher than in 2005, largely attributed to floorspace expansion in that period.
“The 4.3 Mt (10 per cent) decrease in emissions in the residential category between 2005 and 2022 is largely driven by energy efficiency improvements, with smaller decreases due to warmer weather and reduced consumption of light fuel oil,” the inventory report states.
Looking at smaller, but growing sources of GHGs, off-road combustion vehicles and machinery for grounds-keeping, property maintenance and snow removal produced 6 Mt of emissions in the commercial/institutional buildings sector in 2022. That’s up from 4.5 Mt in 2005. Residential emissions from those sources are on the inverse trajectory, tallying 0.87Mt in 2022 versus 1.2 Mt in 2005.
In contrast, residential buildings are a greater source of emissions from biomass combustion via fireplaces, wood-burning stoves and furnaces — amounting to 3.9 Mt in 2022. “Biomass used to generate electricity is a small source of emissions in the commercial/institutional subcategory,” the inventory report observes.
Buildings are also a source of fugitive emissions leaking from the piping of gas-fired appliances such as water heaters, stoves and clothes dryers. The inventory report cites this as a combined number for the commercial/institutional and residential sectors, totaling 1.7 Mt in 2022. That’s an increase from 1.4 Mt in 2005.
The inventory report flags the changing emissions profile related to hydrofluorocarbons (HFCs) commonly used in refrigerants and blowing agents, although this is categorized as GHGs arising from industrial production and product use rather than directly attributed to the buildings sector. Releases from HFCs accounted for 10.6 Mt of emissions in 2022. That’s a 120 per cent increase from 2005, reflective of their arrival in the marketplace to replace ozone-depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), but a drop from an 11.5 Mt peak in 2018.
The recent pullback on emissions aligns with the in-progress phase-down of HFC imports under the Kigali Amendment to the Montreal Protocol. That mandated a 10 per cent reduction in HFC imports, relative to the average net imports in 2014-2015, for the five-year period from 2019-2023. The next step of the phase-down — a 40 per cent reduction — is now in place until the end of 2028.
The GHG inventory report categorizes construction separately from buildings. For 2022, 1.6 Mt of construction emissions are attributed to on-site energy combustion, up from 1.4 Mt in 2005. However, a seemingly far greater amount is more difficult to quantify precisely since emissions from off-road vehicles and machinery for construction, mining and manufacturing are lumped together as one number. This tally was 18.6 Mt in 2002, an increase from 16.2 Mt in 2005.
