Some parts of the climate movement are talking about war as more than a metaphor. Youth climate campaigner Nayeli Jimenez has recently joined 350.org founder Bill McKibben in suggesting we actually go to war on climate change. Jimenez is part of Our-Time.ca, a coalition of volunteers pushing for a Green New Deal for Canadians. Weeks before May shared her war story, Jimenez told me that Canada created 28 new Crown corporations during WWII, and said that’s just one example of the kind of swift, sweeping action needed to move Canada off our current course and reach our Paris Agreement targets.

David Phillips, senior climatologist with Environment and Climate Change Canada, says the latest measurements put Earth’s temperature roughly 1 C above pre-industrial levels, while Canada has warmed 1.7 C in about half the time as the rest of the world. Temperatures in some parts of Canada have already risen well above 2 C—particularly the Arctic and northern continental regions. It’s likely the whole country will surpass 2 C by the time Canada has another election.

We talk about climate change as a “crisis” or “emergency” now, because the latest Intergovernmental Panel on Climate Change reports say we have 11 years to nearly halve the world’s carbon emissions if we want to avoid “catastrophic” changes. If we don’t change course, we could see as much as 7 C of warming , causing the extinction of most species on the planet.

If you’ve been reading about climate change this week, chances are you’ve come across a war analogy. Green Party leader Elizabeth May used one to pitch her platform Monday , and competing columns in the New York Times and CBC have since declared war metaphors are an imperfect way to describe our current existential threat .

It’s strange to hear environmental activists talk this way. As this week’s columnists have noted, WWII was a fraught, disorganized, and deeply racist time—not something anyone should nostalgically wish to bring back. Compared to our current threat, the enemy was more clearly defined then, and the methods of “combat” more straightforward (see: violence).

But the more we learn about the destruction that two-plus degrees warming will bring—the wildfires, the storms, the floods, the literal shrinking of our borders as sea levels rise—the more climate activists and researchers are looking to a time before boomers were born for lessons on how to tackle the biggest global threat of our time.

Author and former Canadian Centre for Policy Alternatives director Seth Klein is working on a book that looks to prime minister Mackenzie King’s WWII response for clues on how we could potentially transform Canada’s economy. I asked him what Canada might look like if we actually used war measures to rapidly build renewable energy, retrofit homes, plant carbon-capturing trees, and upgrade transportation.

Klein says Jimenez is talking about the 28 Crown corporations created by C.D. Howe, one of the leaders in King’s war cabinet. These new companies churned out typical war stuff: timber, steel, rubber, fuel, ships, aircraft, tanks. All told Canada ended up making some 800,000 military transport vehicles, 50,000 tanks, and 16,000 planes and jets. British Columbia alone built 300 ships in five years, according to Klein.

Canada also worked with private companies, but the government took a very hands-on role planning how each industry would work together, thanks to the creation of the Department for Munitions and Supply. “It wasn’t just that we were building a lot of planes and ships, we were coordinating the supply of all the core ingredients of the economy,” Klein said. “We fundamentally retooled the economy in the space of just a few years.”