In a personal message attached to the Green Party's election platform, Elizabeth May invokes the Second World War, Winston Churchill and the evacuation of Dunkirk to frame the challenge of combating climate change and the need for both courageous leadership and collective action.

Unfortunately, May's grasp of the historical details is a little shaky. But this isn't the first time she has used the Second World War as a metaphor. Twelve years ago, she caused a minor stir when she compared Stephen Harper's climate policies to Neville Chamberlain's appeasement of Hitler. She's also not the only public figure who has used the war effort to explain what is required now.

There is something to be said for using history to frame the issue. These are, without a doubt, consequential days. But tidy stories about Churchill's fortitude might only understate the scale and complexity of the current challenge.

Climate change is not much like modern war.

If, for example, climate change was a rogue state or an international terrorist organization that posed a grave and immediate threat to Western peace and stability, some coalition of nations likely would have agreed already to bomb it into submission. If global warming could be solved with fighter jets, somebody would have tried by now.

An image from the Christopher Nolan film Dunkirk. (Warner Bros.)

If climate change could be tackled as a military threat, the debate in this country would be flipped on its head. The Conservatives would be most eager to take aggressive action and there would be no grumbling about how Canada's contribution to the problem was much smaller than that of China or the United States. Joe Oliver, the former Conservative finance minister, would not be arguing that, all things considered, climate change might work out okay for Canada.

If recent history is any example, the Liberals, New Democrats and Greens would be less enthusiastic about dropping bombs. But there might still be a general agreement that Canada should make a serious contribution somehow. Public commentators would not look kindly on anyone who suggested it should be up to other countries to deal with the problem.

But climate change is not as simple as war.

For one thing, recent military interventions haven't asked anything of the average citizen. Only those members of the military charged with carrying out the mission, and their families, have faced any kind of sacrifice.

In that respect, climate change might appear to have more in common with the two world wars of the 20th century, when the home front was more directly engaged in the fight. The federal income tax, for instance, was introduced in 1917 as a means to fund the Canadian war effort. Food rationing was mandated during both world wars.

British Prime Minister Winston Churchill and Canadian Prime Minster William Lyon Mackenzie King arrive at the Château Frontenac in the 1940s, during one of the two Québec Conferences hosting the allies. (CBC)

Perhaps Canadians were more deferential to authority and less cynical in those days. But the heaviest request for sacrifice — conscription for overseas military service — still put an enormous strain on national unity. The Borden government's introduction of conscription in 1917 angered farmers in the West, led to riots in Quebec and precipitated "the worst election campaign in Canadian history."

Mackenzie King's government subsequently tried to fight the Second World War with a voluntary force for three years before asking Canadians to approve conscription in a national plebiscite in 1942. The result once again split the country along linguistic lines: eight provinces were overwhelmingly in favour, Quebec was overwhelmingly opposed.

King — who famously said, "conscription if necessary, but not necessarily conscription" — stalled for another two years before following through, effectively limiting the number of conscripted men who were sent into battle before the war's end in 1945. War, in that case, required compromise.

Cinematic moments of leadership make for fun movies, but the task of holding a country together and leading it through moments of great consequence is always more complicated than we're sometimes led to believe.

The enemy is ... us?

For all their complications, real military campaigns still, at least, benefit from the presence of tangible and foreign enemies. Climate change, on the other hand, is about the society we have constructed. It's one thing to rally your fellow citizens to fight Adolf Hitler and the Nazis (particularly when, as in Churchill's case, your own country's liberty is at stake). It's something else entirely to deal with the way we ourselves live, what we do and how we do it.

Putting a price on carbon is not nearly a political event on the same level as conscription (which, by the way, did not come with the offer of a full refund). But like conscription, climate policy already has produced significant regional splits in public opinion, with opposition most heavily concentrated in Alberta and Saskatchewan, two provinces that rely on oil and gas development.

In their party platform, the Greens propose completely phasing out the production of bitumen within 15 years and transitioning energy workers to new jobs. To do that without tearing the country apart would be a remarkable achievement (the Greens are currently polling at 5 per cent in Alberta).

If climate change is like war, it can't be simply reduced to a bidding contest over who would set the most ambitious targets. It requires leadership. But it also requires bringing a country and its citizens along. The details of policy — like the details of history — matter.

To underline the threat, challenge the complacent and motivate the hopeful, war is a tempting metaphor. The sacrifices and efforts of previous generations can reinforce a sense of responsibility toward the present and the future. Historic leadership can provide enduring inspiration.

But if fighting climate change has anything in common with World War II, it's the fact that it will be hard — and more complex than we might choose to imagine. Winning a war is seldom easy.