The Liberal Party upped their climate promises on Tuesday, matching the target of net-zero emissions by 2050 announced by 65 other countries and the EU at the United Nations on Monday.

But the party did not spell out exactly how they planned to reach the new target. “I’m not going to stand here and say what our exact plan is until 2050, because we need to make that plan with experts,” Liberal candidate Catherine McKenna, who served as Trudeau’s environment minister, said in Ottawa on Tuesday morning.

While the Liberals promised Tuesday to set “legally-binding, five-year milestones” in order to reach net-zero emissions by 2050, McKenna did not answer questions from reporters about details like penalties for the legislation, or how specific provincial economies would have to restructure to meet their target. “We don’t know every single solution,” McKenna replied, when asked why she was unable to give greater clarity on the Liberals’ plan. “We need to figure this out as a country.”

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Tuesday’s announcement brings the Liberals in line with a vow made previously by the Green Party, though the Greens have also promised a target of reducing Canada’s 2005 greenhouse gas levels 60 per cent by 2030. The Liberals’ target throughout their last mandate was a 30 per cent reduction by 2030; they’ve now announced an intention to exceed that goal, but have not identified a new one.

Their original 30 per cent-by-2030 reduction goal was part of Canada’s 2016 commitment to the global Paris Agreement, which aims to hold global warming below 1.5 degrees Celsius. Some concern was raised during the Liberals’ recent term in office about whether the government was on track to reach their targets — including a Parliamentary Budget Officer report saying the Liberals’ carbon tax would have to double by 2030, on top of existing policies, in order to meet their Paris goals.

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McKenna said, at the time of the report’s release, that the government didn’t plan to increase their carbon tax. (In late August, there was some confusion after the Globe and Mail reported McKenna saying the $50 a tonne cap would be consulted upon towards the end of the next mandate. Conservatives at both the federal and provincial level viewed her comments as an admission that the tax could be raised; McKenna, meanwhile, denied again that an increase was planned.)

Asked Tuesday morning about claims that the government was not on track to meet their existing goals for 2030, let alone new targets, McKenna rebutted that the government was “three quarters of the way there” with existing measures.

The party noted Tuesday that in a net-zero future, some sectors would still be able to emit carbon pollution, but their emissions would be offset by other actions like planting trees. The Liberals also pledged Tuesday to introduce legislation to give energy workers training and opportunities “in the future economy.”

McKenna did not give an estimate when asked how many traditional energy sector workers would have to make a transition under their plan. “The transition is happening already,” McKenna replied, claiming there were “five times” more jobs in renewable energy. (She did not reference any specific data or report while making that claim on Tuesday.) “This is not about targeting one sector,” she said.

Party leader Justin Trudeau also spoke about the pledge later in the afternoon — while announcing in Burnaby, B.C. that a re-elected Liberal government would cut corporate taxes in half for companies that develop technologies, or manufacture products, with zero emissions. (Small businesses’ corporate taxes would be cut from 9 per cent to 4.5 per cent, and larger companies would receive a tax cut from 15 to 7.5 per cent.)

Trudeau also did not offer specifics of the Liberals’ plan to reach their new 2050 target, and repeated McKenna’s statement that their government was three quarters of the way to their existing goals. When asked by a reporter why the Liberals weren’t offering specifics, Trudeau did not give an answer about his party’s reasoning, instead saying that the government’s existing emissions reduction target was “inherited” from the previous Conservative government.

In his remarks, Trudeau made several links between environmental issues and the economy, noting that companies could capitalize on curbing the effects of climate change. “This is the next great economic frontier,” he said. Later, he warned of potential financial wounds from a worsening environment.

“You pay for climate change when your basement floods,” Trudeau said, also warning of higher insurance premiums in future, or negative impacts on tourism from forest fire smoke.

The Conservative Party alleged on Tuesday that the Liberals’ new emissions reduction target would “destroy” the economies of British Columbia, Alberta, Saskatchewan and Newfoundland, as well as Ontario and Quebec’s manufacturing sector. “Hundreds of thousands of people will lose their jobs,” the party claimed in a press release. (Their allegations were not backed up with specific reports or data.)

The Liberals also promised Tuesday afternoon to require federal buildings to be powered completely by clean electricity by 2022, versus an existing commitment of doing so by 2025.

As with other Liberal pledges so far, none of the announcements Tuesday were followed by the release of independent costing assessments by the Parliamentary Budget Officer. The party’s own assessment said the clean tech tax cut would cost the federal government approximately $15 million in 2020-21, rising to around $67 million by 2023-24.

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Green Party leader Elizabeth May expressed disappointment in the Liberal announcement on Tuesday morning, telling reporters that making a commitment was good, but the Liberals were making a promise that was 30 years away.

The NDP has also pledged to revise Canada’s pollution targets if elected this fall, and to entrench its own emission reduction targets within legislation. The federal Conservatives have neither abandoned the government’s current 30 per cent emissions reduction target, nor fully committed to reaching it —claiming that their environment plan was Canada’s “best chance” to meet the Paris targets.

*This story has been updated with comment from Liberal candidate Catherine McKenna, Liberal leader Justin Trudeau, Conservative leader Andrew Scheer and Green Party leader Elizabeth May.