Justin Trudeau said today a re-elected Liberal government would protect a quarter of Canada's natural land and ocean habitats by 2025, and would become a global champion in setting international conservation targets.

During a campaign event in Sudbury, Ont. after taking a morning canoe paddle around a local lake, the Liberal leader also promised today to launch a new program aimed at encouraging more youth and families to enjoy the great outdoors.

The promised land and ocean conservation target — 25 per cent by 2025 — is an increase over the current target of 17 per cent for land protection and is nearly double the 12.4 per cent of Canada's land habitats currently being protected.

"We know that not only can we protect 25 per cent of our land and 25 per cent of our oceans by 2025, but we must," Trudeau said.

"It is an essential part, not just of protecting biodiversity, not just of fighting climate change, but of also ensuring that future generations have the opportunities we've had growing up and the economic opportunities that come with biodiversity and investments in ecotourism in general. We know that this is the path forward for Canada and that's why we're going to do it."

The Liberals say they would work toward protection of 30 per cent of land and marine habitats by 2030 by tapping into Indigenous knowledge, stewardship and leadership and collaborating with other levels of government within their jurisdictions, according to the party's background materials.

Liberal Leader Justin Trudeau says his party would increase protected land and ocean areas to 25 per cent by 2025. 0:39

The Liberals also promise to push for a 30-per-cent conservation target by 2030 for countries around the world at international gatherings.

Today's announcement also includes a plan to teach every young Canadian the skills to camp by Grade 8, and a promise to create a national Experience Canada program that would help 75,000 lower-income families spend up to four days in one of Canada's national or provincial parks every year.

That program would include camping accommodations and a travel bursary of up to $2,000 to allow lower-income families to experience places across like Killarney, Banff, Gros Morne and the Cape Breton Highlands, according to the Liberals. The program also would partner with Via Rail to make the opportunities accessible and affordable for even more Canadian families, the Liberals say.

Prince Edward Island is keeping a close watch on the impacts of climate change on its coastlines. (John Robertson/CBC)

According to the Liberal Party, the measures would have a net cost of $75 million in 2020-2021, which would rise to $150 million by 2023-2024.

Independent costing by the Parliamentary Budget Officer was not provided; the Liberals are saying that further details will be released "over the course of the campaign."

Today's announcement is the third in a series of Liberal promises related to the environment and climate change this week.

Trudeau to march in Montreal climate rally

They come as young people prepare to take part in marches around the world calling for urgent action by political leaders to tackle climate change. Swedish teenage climate activist Greta Thunberg will take part in what's expected to be a massive march drawing hundreds of thousands to the streets in Montreal Friday.

Today, Trudeau confirmed he will also be in attendance.

"I look forward to marching with thousands of Canadians tomorrow in Montreal, like people are marching right across the country and around the world to fight for the environment," he said.

On Tuesday, Trudeau announced that a re-elected Liberal government would halve the corporate tax rate for companies that develop or manufacture products with zero emissions — part of the party's plan to move to net-zero emissions by 2050.

Net-zero emissions plan

Eligible sectors could include manufacturing related to renewable energy, production of renewable fuels, zero emission vehicles and batteries for them, carbon capture and removal technology and electric vehicle charging systems.

It's part of the wider Liberal promise to push Canada to net-zero carbon emissions by 2050. The European Union and other countries made the same climate pledge at the United Nations in New York City this week.

The Liberal Party's plan is to set legally-binding, five-year milestones to reach net-zero emissions in 30 years. The party says the net-zero plan would be based on the advice of scientists, economists and other experts, as well as consultations with Canadians.

Net-zero means some sectors could still emit carbon pollution, but those emissions would be offset by other actions such as planting trees.

On Wednesday, Trudeau said a re-elected Liberal government would give Canadians access to interest-free loans of up to $40,000 to upgrade old furnaces, replace leaky windows or retrofit their homes to make them more energy-efficient and resilient to floods and wildfires caused by climate change.

The Liberal Party says the program would offer a free energy audit and would help to retrofit about 1.5 million homes.

The Liberals have also pledged $100 million in skills training to make sure there are enough qualified workers to handle the energy audits, retrofits and net-zero home construction.

The Liberal climate change plan also would create a low-cost national flood insurance program to help homeowners in high-risk flood zones, complete flood maps, develop a national action plan to help homeowners in flood zones with potential relocation, and introduce an Employment Insurance Disaster Assistance Benefit to help people whose jobs and livelihoods are affected by extreme weather.