Carbon emissions increased across all six regions in 2023.

Total emissions increased across the six regions of the GTHA, where all municipalities are struggling to stay on track with their climate targets. Transportation and buildings remain the two highest-emitting sectors in nearly all regions. The City of Hamilton is the exception, where the sizeable steel manufacturing sector makes industry the highest emitting sector. Cement production concentrated in Durham and Peel and agriculture in Durham contribute considerably to their respective emissions.

Per capita emissions decreased across most regions, with the exception of York where they remained the same and Hamilton where there was a small increase. The City of Toronto continues to have the lowest per capita emissions in the region, largely due to the higher use of transit, walking, and cycling, enabled by its density.