Prime Minister Justin Trudeau told a town hall meeting in Ontario Friday that Canada needs to “phase out” the oilsands, even though it can’t be done immediately.

“We can’t shut down the oilsands tomorrow. We need to phase them out. We need to manage our dependence on fossil fuels,” Trudeau said in response to a question about his government’s commitment to the environment, at the meeting in Peterborough.

Wildrose leader Brian Jean responded on Twitter that Trudeau would have if “to go through me and 4 million Albertans first.”