Buildings continue to be the largest emitting sector in Halton, Peel, and Toronto. Emissions come from natural gas (90%), of which 71% is consumed on-site for space and water heating, and electricity (10%) generated using natural gas.
Residential construction in 2021 was 19% higher than a 20-year historical average, indicating that buildings will continue to play a crucial role in mitigating emissions across the GTHA. Municipal adoption of ambitious green development standards is critical in achieving the reductions needed in this sector.
Natural Gas for Heating
“Natural gas” (also known as methane or fossil gas) consumption for space and water heating continues to drive most building emissions. In 2021, total building emissions were 22.6Mt, with nearly 90% coming directly from natural gas combustion. And if upstream fugitive methane emissions are included, that number is 30% higher.
Despite warmer weather, natural gas consumption in this sector increased by 1.7% overall in 2021. Residential consumption dropped by 3%, while industrial and commercial consumption increased by 16% and 1%, respectively, indicating a partial return to the office.
Emissions have climbed back to 2019 levels when normalizing for weather, and the longer trend indicates that emissions have remained relatively unchanged since 2015. We must stop delays in this sector, which will result in having to make drastic reductions in future years to meet targets. Direct action and policies towards electrification and the use of alternative fuels are needed from all levels of government and the private sector. Policies like Canada’s Green Building Strategy, the Ontario Building Code and municipal green development standards can play an important role in the decarbonization of buildings.
Emissions from electricity consumption in the GTHA increased by 28% in 2021, up from 1.8 MT to 2.3 MT, rebounding to levels not seen since 2016. This change is attributable to an increasing proportion of natural gas generation in Ontario’s electricity system.
Electricity emissions are primarily driven by total demand and the emissions intensity of the grid. In recent years, changes in total emissions have been primarily driven by the latter, reflecting changes in the amount of natural gas generation in the grid, while demand has remained relatively constant.
Electricity emissions are forecasted to triple by 2030. Increasing temperatures, nuclear refurbishments, and growing demand as we electrify vehicles and heating put our aging electricity grid at risk. Supplying this demand with natural gas as planned will significantly increase emissions.
Governments, utilities, and system operators must make necessary investments to modernize the grid, build non-emitting supply and storage, develop distributed energy resources, and scale up conservation efforts. Ontario’s phase-out of coal in 2014 was a major achievement and the most significant climate action in the last 20 years. Continuing along our current path threatens to reverse much of that progress and undermine efforts to decarbonize our building, transportation, and industrial sectors.