OTTAWA 鈥 Green party Leader Elizabeth May says if elected, her party would welcome the arrival of tens of thousands of new refugees to Canada who may soon be forced to leave their homeland because of climate change.

In an interview with CTV鈥檚 Question Period on Sunday, May said her party would work to ensure communities in Canada are prepared for the influx of newcomers.

"We have right now, depopulated areas across the country. We can build up infrastructure by 2030 and 2040 to accept far more people in regions, for instance in the Prairies, where there are depopulated places, in Atlantic Canada, and northern Quebec."

May based her "tens of thousands" estimate on the Intergovernmental Panel on Climate Change鈥檚 assessment that by 2050, the world could expect to see approximately 200 million more refugees displaced by environmental crises should the planet continue to warm at the rate it is now.

This would be the result of changes to things like shoreline disruption, coastal flooding, and agricultural disruption.

"One of the points Greens make is we have to prepare," May said. "By geography, we鈥檙e one of the biggest countries in the world, by population one of the smaller. We have an obligation; we鈥檝e been one of the biggest polluters."

May started "climate week" in Calgary marching with local residents and moved east to Montreal by Friday, joining hundreds of thousands of protesters advocating for increased climate action.

Liberal Leader Justin Trudeau and NDP Leader Jagmeet Singh also marched in Montreal and Victoria respectively, while Conservative Leader Andrew Scheer and People鈥檚 Party Leader Maxime Bernier opted out.

May expecting new 'passing grade' on party costing

On Question Period, May also addressed criticism she and her party have faced over the costing of their election promises, which was released on Wednesday. As of Sunday morning, the Greens were the only federal party to have a fully-costed plan.

In the parliamentary budget officer鈥檚 cost analysis, federal spending would increase by more than $60 billion per year. This would cover big ticket items like universal drug coverage, free tuition, universal childcare, and efforts to fight climate change.

Ten of the party鈥檚 estimates are rated as having "moderate uncertainty" and over 13 have "high uncertainty."

To that end, former PBO Kevin Page 鈥 now with the Institute for Fiscal Studies and Democracy 鈥 gave the plan a failing grade in his report [link] saying it yielded 鈥渟erious gaps in economic and fiscal assumptions.鈥

May on Sunday said her party didn鈥檛 provide background reports and risk assessments that would have turned some of that doubt into validity.

"The bans of estimates of uncertainty are the Parliamentary Budget Office鈥檚 own numbers," said May. "The [documents] that are missing, it鈥檚 not as if they don鈥檛 exist, it鈥檚 that we hadn鈥檛 sent them to Kevin Page. So those things will be reviewed. I think you can expect in the next couple of days a passing grade."

She admitted that the costing on the Green鈥檚 pharmacare proposal at $27 billion was "far more than she expected."

May clarifies stance on Bill 21

May doubled down on her stance on Quebec鈥檚 controversial secularism bill, which bans some civil servants from donning religious symbols and clothing.

During a televised leaders鈥 debate on Sept. 12, May said she would think about building out a strategy to create jobs for those who can鈥檛 find work in the province and are pushed out because of it.

She has since clarified her argument saying "no one should have to leave anywhere" and indicated that room could be made in other industries under federal jurisdiction, as opposed to provincial, for those who find themselves out of work because of the law.

May added that the issues surrounding Bill 21 needed to be dealt with within the province, not through federal intervention.

"On this and I think on no other issue you find the other party leaders unified not because we don鈥檛 think Bill 21 is inappropriate and a violation of charter rights," said May. "We鈥檙e looking at Bill 21 as being one of those issues that could threaten to reopen Canada-Quebec friction. None of us want to do that."

Scheer, Singh, and Bernier have also definitively stated they would not intervene, while Trudeau has kept the door open.

May on altered image of reusable cup

While the Greens have been applauded for their transparency on election platform budgeting, they came under fire this week for using Photoshop to alter a photo of their leader holding a single-use cup鈥攁lbeit a compostable one.

In the modified photo, May is seen clutching a reusable cup with a Green party logo pasted on the front and a reusable metal straw coming out the top.

In a follow-up statement, May said she was "completely shocked" the image had been changed to appear more pro-recyclable.

She reinforced this stance on Sunday, saying it was 鈥渕onumentally idiotic鈥 and she doesn鈥檛 know why the individual thought it was "appropriate."

"I know they鈥檙e modified, I know they鈥檙e apologetic. I鈥檓 not throwing anyone under a bus here. Obviously I wish they hadn鈥檛 done that, I can鈥檛 see a single reason to have done that because I鈥檓 transparent, I鈥檓 open."