Toronto City Council's emissions reduction targets are documented in the TransformTO plan (pdf). These targets are based on Toronto's 1990 emissions: 30% by 2020; 65% by 2030; Net zero by 2050, or sooner. In the Paris Agreement, Canada pledged to aim to keep global temperature increases well below 2 degrees C and to aim to keep them below 1.5 degrees C.

According to the IPCC for a likely chance of remaining around 1.5oC the global carbon budget is 420 GtCO2e,

Toronto's share of the global population is 0.03% so the population-share of the global carbon budget is approximately 160 MtCO2e and will be exceeded by 2033.

Toronto's share of global emissons is 0.05% so the emissions-share of the global carbon budget is 260 MtCO2e and will be exceeded by 2042.

The chart below was generated by Climate Action Now and the calculations that generated it (and others) can be examined here.