California and Quebec have closed the joint carbon market to Ontario, preventing companies from dumping some $2.8-billion in emissions allowances after premier-designate Doug Ford announced an end to the provincial cap-and-trade system. While Mr. Ford’s decision could provoke lawsuits from companies that purchased allowance, the province is also set to join Saskatchewan’s legal fight over the federal government’s right to impose its carbon tax where provinces have not levied their own carbon price, whether by direct tax or cap-and-trade system. The move by Ontario’s partners in the Western Climate Initiative comes as Prime Minister Justin Trudeau’s principle secretary, Gerry Butts, suggested Mr. Ford’s action has left the province open to lawsuits.