Emissions by Sector
Emissions are now at the highest levels since 2015. Continuing to delay reductions will compromise reaching climate targets.
Total 2022 carbon emissions 24.7 MtCO2eq
% Change in emissions +9.3%
% of GTHA emissions 46%


In 2022, total building emissions rose by 9% to 24.7 MtCO2eq, reaching the highest levels since TAF began publishing an inventory in 2015. Part of this can be attribued to a colder 2022. But natural gas and electricity consumption also increased.

Our region is growing quickly, and deep energy efficiency improvements aren’t happening fast enough to keep up with the scale of new development and the increase in the province’s use of gas-fired electricity generation.

Emissions came from natural gas (89%), the majority of which is consumed on-site for space and water heating, and electricity (11%).

Total Building Emissions, 2015-2022 (MtCO2eq)

Building emissions remain the largest emitting sectors in Halton, Peel and Toronto.

Per capita building emissions range from a low of 2.5 tonnes CO2eq/person in Durham to a high of 5.3 tonnes CO2eq/person in Hamilton.

According to Ontario’s Energy and Water Reporting and Benchmarking dataset, only about a third of GTHA buildings 100,000 sq. ft. or larger saw at least some reduction in GHG emissions intensity between 2020 and 2021.

TAF will review the 2022 dataset when it is released to assess any progress in this area. Notably, the average GHG emissions intensity of GTHA multi-residential and commercial buildings in the dataset is 29 kgCO2/m2.

Residential construction was 20% lower in 2022, while non-residential building construction increased by 15%.

This indicates that buildings will continue to play a crucial role in mitigating emissions and reaching climate targets across the GTHA.

Building retrofits in particular help drive reductions in energy use and carbon emissions across existing buildings, while also generating a multitude of co-benefits. For example, it is estimated that building retrofits have the potential to create 33,000 direct jobs in the GTHA annually.

Scope 3 Embodied Carbon: Together, concrete and steel emissions are responsible for nearly half of total embodied carbon emissions in buildings. A TAF-funded study benchmarked the embodied emissions of building materials, reporting that the average annual embodied emissions of all new low-rise homes built in the GTHA is 0.84 MtCO2eq. Another TAF-funded study showed that high-rise building materials account for 465 kgCO2eq/m2, totaling 1.6 MtCO2eq annually in the GTHA. Adding these two sectors together means that the GTHA’s total embodied emissions in new buildings are at least 2.5 MtCO2eq.

Natural Gas

Natural gas, also known as methane or fossil gas, is largely consumed onsite for space and water heating and continues to drive the majority of building emissions.

Gas used for heating is responsible for 74% of residential emissions, 79% of commercial emissions, and 20% of industrial emissions.

Natural Gas Emissions (MtCO2eq)

In 2022, natural gas emissions increased by 8% to 22 MtCO2eq. Specifically, residential and industrial consumption increased by 6%, while commercial consumption increased by 11%. When normalizing for weather (2022 was a colder year than 2021), natural gas weather normalized emissions increased by 1% across the GTHA. Residential weather normalized emissions decreased by 1%, while commercial and industrial emissions increased by 3% and 4%, respectively.

To reverse trends, we need to make drastic reductions in natural gas consumption. Policies are needed to scale conservation, implement existing building performance standards, restrict the use of gas-fired heating equipment, and streamline processes and services to enable electrification across the building sector.

Scope 3 Fugitive Methane: TAF reports on fugitive methane that leaks from extraction, fracking, pipelines, and distribution, the full life cycle of natural gas. Including fugitive methane demonstrates that natural gas combustion emissions are 30% higher than typically reported. Ignoring this important source of upstream emissions can undermine climate action priorities, particularly where natural gas is marketed as a “clean” fuel source.


Electricity emissions in the GTHA increased by 26% in 2022, one of the largest jumps in a single year.

Emissions have reached their highest levels since 2015, when the last of the province’s coal-fired units were still being phased out.

Electricity Emissions (MtCO2eq)

Rise in electricity emissions is primarily driven by increasing emissions intensity of the grid.

Demand continues to remain relatively constant, with electricity consumption increasing slightly from 58.0 TWh in 2021 to 58.8 TWh. The 24.5% increase in emission intensity, attributable to the increased utilization of the province’s gas-fired units, is the primary driver of growing emissions across this sector.

This upward trend will continue in the absence of investments in clean alternatives.

Electricity Consumption (TWh)

The Independent Electricity System Operator (IESO) projects that electricity demand could nearly double by 2040. The current near-term plan for supporting the electrification of our buildings, vehicles, and industries is to turn up the dial on our existing gas plants and build new capacity. Many of the gas plants have recently received upgrades and contract extensions out to 2035. This runs counter to upcoming federal regulations, and the long-term plans of almost every other jurisdiction in North America.

Forecasted ON Electricity Emissions, 2015-2040 (MtCO2eq)
Source: IESO 2021 APO

The solutions are well understood.

We need to prohibit any new or expanded gas-fired electricity generation, scale energy efficiency and conservation efforts to lower energy demand, invest in distributed energy resources to increase load flexibility, and invest in new local and utility-scale clean generation