Are TransformTO targets good enough?

Do you remember this? it was a result of the ice storm in Toronto in 2013. There was also the heat wave in 2016. We can expect more frequent climate change events in the future.

Toronto's emissions reduction targets are documented in the TransformTO plan (pdf):

  • 30% by 2020 (19 MtCO2e per year)
  • 80% by 2050 (5.4 MtCO2e per year)

Both targets are based on Toronto's 1990 CO2e emissions. If Toronto follows the TransformTO plan our cumulative emissions will be approximately 575 MtCO2e. The Intergovernmental Panel on Climate Change (IPCC) report included estimates for the maximum global cumulative CO2 emissions in order to keep global temperatures under various levels. I believe that Toronto's share of these global budgets should be based on our share of the global population (0.03%). The budgets that I used are for a likely (greater than 66%) chance of global temperature increases remaining under 1.5 and 2 degrees C. (Aside: would you get on a plane if you knew that you had a 30% chance of not surviving? I wouldn't but then I also do not get on planes because of their emissions).

If Toronto wants to do our share to prevent global temperatures from increasing by more than 2oC, the limit on our cumulative emissions (based on our share of the global population) is 230 MtCO2e.

I created this animated chart which illustrates how the TransformTO targets compare to our population-based shares of the limits for 1.5oC and 2oC.

The Paris Agreement did not specify how countries should share the emission limits. There are different sharing strategies. One is based on our share of global emissions. On that basis our remaining emissions-based shares are 80 MtCO2e for a likely chance of remaining below 1.5oC and 440 MtCO2e for below remaining below 2oC. Although that gives us longer to meet our Paris Agreement pledge, it does so at the expense of developing nations.