Ontario's environmental watchdog is criticizing the Progressive Conservative government for dismantling the province's cap-and-trade system without putting in an effective climate change program to replace it.

In a report released Tuesday, environmental commissioner Dianne Saxe says the government's decision could reverse the progress Ontario has made in cutting greenhouse gas emissions over more than a decade.

She says the climate change provisions in proposed legislation to scrap cap and trade -- known as Bill 4 -- are "much too weak."

Ontario Premier Doug Ford made cancelling cap and trade one of his key campaign promises and further vowed to fight Ottawa's carbon pricing plan for provinces that don't have their own.

Environment Minister Rod Phillips defended the move on Tuesday, saying Bill 4 specifies there will be emissions targets.

Phillips said a more detailed climate change plan will be presented this fall and the environmental commissioner will be better able to judge then.

"As I said to her directly when we met, respectfully, we do not take well to folks telling us that we should not live up to the promises that we made," he said.