A report from the Ontario Society for Professional Engineers predicts carbon emissions will double in Ontario as more wind and solar projects are added.
The report says all of Ontario's nuclear reactors would need expensive engineering changes to provide clean flexible back up power.
But it says Ontario is relying on natural gas as a back up for wind and solar instead of nuclear.
It says Ontario is forcing nuclear plants to reduce output, to make room for additional wind and solar with natural gas back up.
Ontario currently produces electricity at less than 40 grams of CO2 emissions/kWh.
But by 2032, that will increase to about 200 grams of CO2 emissions/kWh as more wind and solar projects come on line.
