"But the Opposition denies that climate change is real. And look no further than Ontario to find a provincial government that is wasting taxpayers' money fighting climate action in court while ignoring their commitments to protect species at risk."

"Canada is warming at nearly twice the global rate and even faster in our north," Trudeau said, citing a report from Environment and Climate Change Canada released earlier this month.

Trudeau, speaking at the Nature Champions Summit, also called out Ontario Premier Doug Ford for challenging the constitutionality of the federal government's carbon pricing plan in court.

Prime Minister Justin Trudeau accused his Conservative rivals of denying that climate change is real during a speech to an environmental summit in Montreal Thursday.

The prime minister was referencing how Ontario Tories are considering a change that would let developers pay a fee instead of taking actions to protect more than 240 species at risk in the province.

"It's shortsighted and irresponsible," he said. "And frankly, Canadians deserve better."

On April 1, the federal government imposed a carbon tax of $20 per tonne — set to rise to $50 per tonne by 2022 — on four provinces that refused to put their own price on emissions: Saskatchewan, Ontario, Manitoba and New Brunswick. Manitoba had planned to introduce a $25-per-tonne tax that would not rise per year, but scrapped it after the federal Liberals said it wasn't enough.

Though people in those provinces are being promised rebates of hundreds of dollars per family to offset costs, Saskatchewan and Ontario are fighting against the plan in court, arguing it exceeds the federal government's jurisdiction. New Brunswick is backing Saskatchewan's challenge.

Manitoba Premier Brian Pallister confirmed this week that his government will also launch a challenge, as will Alberta's next premier, Jason Kenney, after he scraps that province's carbon tax.

Federal Tory Leader Andrew Scheer has pledged his party will repeal Trudeau's carbon pricing regime if his party forms government after this fall's election.

Tories have not revealed their plan to curb greenhouse gas emissions, even though Conservative MPs — with the exception of Ontario's Cheryl Gallant — voted in 2017 to support Canada implementing the Paris climate accord. Under the Paris agreement, Canada is committed to reducing emissions by 30 per cent below 2005 levels by 2030.

While Liberals often call on Scheer to make clear what he would do to fight climate change, the Tory leader has in the past acknowledged the problem.

"Look, I think climate change is real. The Earth's climate is constantly changing and I think human beings have an impact on their environment," Scheer told CBC Radio's "Metro Morning" in October.

Asked at the time if that meant he believes climate change is created by human activity, Scheer responded: "I believe absolutely that human beings have an impact on their environment."

'Climate change is real and it is a global problem': Tory environment critic

Tory environment critic Ed Fast fired back by saying that Trudeau is not being truthful.

"The Conservative party has been very clear. Climate change is real and it is a global problem that requires global solutions," Fast told HuffPost Canada. "If we think that we can do this all by ourselves here in Canada, we're kidding ourselves."

Fast did not provide details of how a Scheer government might curb emissions, but said Canada is in a "perfect position to deploy world-leading clean technology" to contribute to an international effort to address climate change.

Tories have made it "very clear" they intend to roll out their environmental plan "in the leadup to the October election," Fast said, adding that the party is already committed to stop the practice of dumping raw sewage into waterways such as the St. Lawrence river.

With a file from The Canadian Press, earlier files

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