Fort McMurray in northern Alberta, Canada, was notorious for one thing: oil sands. That fact is impossible to get away from – the more so now that it’s notorious for something else: burning to the ground. Over the last few days, the images have been apocalyptic: an enormous wildfire approaching houses, hotels and a hospital; lines of cars driving through smoke, sometimes appearing to drive straight through the flames. The blaze jumped over firebreaks, a highway and a river. It was so large it started to create its own weather system: lightning, but no rain. Last Tuesday, the entire city of almost 90,000 people was evacuated. No one has yet been killed by the fire, though two people died in road accidents during the evacuation.

I live in Calgary, about 400 miles south. The talk immediately turned defensive. This is an oil province, already under enormous strain as a result of low oil prices, and people couldn’t help imagining ‘sanctimonious eco-trolls’, as one commentator put it, celebrating Fort McMurray’s misfortune. The outrage began after a tweet about ‘karmic #climatechange’ by Tom Moffatt, who once ran unsuccessfully for a seat in Alberta’s legislative assembly. Responses varied from ‘sickened’ to ‘people who are calling this fire karma should probably go burn in it’. Moffatt has since been suspended from his local government job.

Jen Gerson wrote in the National Post that ‘we need to have a talk about the word “karma”,’ which ‘seemed to be spoken and unspoken among the eco-evangelists’. But if it was spoken, it was rare. Gerson cited only two offenders, both of whom quickly apologised. She added an undefined number of ‘eco-activists’ who ‘piled on’, and she’s right that a few did. But the indignation seems as much a smear tactic as anything else: the idea that there are hordes watching gleefully as a town burns is plausible only if you have bought wholesale the canard that environmentalists don’t care about people.

It’s true that more sober people couldn’t help but see the ‘black irony’ of the fire, as Drew Brown put it for Vice; Fort McMurray is a symbol of the dirtiest side of the fossil fuel economy. ‘Wildfire Rips Through Canadian City, Forcing 80,000 to Flee,’ Slate’s headlineran. ‘This Is Climate Change.’ The New Yorker’s: ‘Fort McMurray and the Fires of Climate Change’. Elizabeth May, the leader of Canada’s Green Party, said the fire was ‘very related to the global climate crisis’. Perhaps even this is too much when the crisis is still so raw; certainly, it’s politically risky. ‘Any time we try to make a political argument out of one particular disaster,’ Justin Trudeau, the prime minister, warned, ‘I think there’s a bit of a shortcut that can sometimes not have the desired outcome.’

Fort McMurray saw 41mm of precipitation between January and April, not much more than half the usual. Average temperatures were weeks ahead of schedule. Last Tuesday, the city hit a record 32ºC –more than double the usual May maximum. It’s always difficult to pin any particular disaster on climate change, and this case is no exception: it’s an El Niño year, which tends to give Alberta warmer, drier winters. But Canadian forest fires now burn annually about twice the area they did in the 1970s, and the American fire season is 78 days longer than it was in 1970, according to the US Forest Service. The US National Research Council estimates that for every degree Celsius of warming, the area of landburned by wild fires in the American west will more than double; similar figures almost certainly apply in Canada.

Forests usually regenerate after wild fires, but as a plant pathologist told the National Geographic last year:

When fires are really large and severe and most of the trees burn up, it’s very difficult for a seed source to survive. Trees can take a century to regenerate. Meanwhile, fires will reoccur andkeep those areas stuck in grass and shrub.

It’s politically unfortunate that climate change resists personalisation and forces us to talk about patterns and statistics. Now may be the wrong time to discuss it, but since disasters like the Fort McMurray fire can’t be blamed directly on climate change, there may never be a right time.

Read more in the London Review of Books

Mike Davis: California Burns · 15 November 2007

Rebecca Solnit: The West Runs Dry · 3 December 2009

Tony Wood: Photographs of the Tar Sands · 21 June 2012

Thomas Jones: How can we live with it? · 23 May 2013

David Runciman: Climate Change Impasse · 24 September 2015