That ought to do it. Trump imposes tariffs on Canada, in part as a distraction from a disastrous Middle Eastern war, in part to shore up the fraying narrative that increasingly destructive fires are more related to forest management, than climate change.
Report above from Minneapolis local TV points out that temperatures in the Boundary Waters area of Minnesota, near Canada, hovered in the 104° F range prior to the ignition, probably caused by lightning.
Data below assembled by Zeke Hausfather shows the relationship between hotter weather and fires.
The new tariffs come after smoke from raging wildfires in Canada drifted into the U.S., blanketing cities including New York, Chicago and Washington. In a Truth Social post Friday, Trump threatened to impose steeper duties on America’s northern neighbor to compensate for the smoke’s impact.
“We are holding Canada responsible for the fact that they are not properly maintaining their Forests, and Brush therein, and the United States is being unnecessarily invaded by filthy, polluted, and unhealthy air, the quality of which is dangerous, and totally unacceptable!” Trump said.
Days later, the president was seen speaking with Carney at Sunday’s World Cup Final. Trump told reporters that Canada needed to stop the wildfires.
“I told them, I mean, you got to stop these fires from coming in and you know poisoning our air,” Trump said. “Our air has been poisoned. Have a good relationship with Mark Carney, but you know we got to stop the fires up there. If we can help them, we’ll help them. But maybe they should pay us some damages or something, or we should do some tariffs.”
Prompt to ChatGPT:
How does the total area of Canadian forests compare to the area of the contintental United States?
Canada has about 347 million hectares (3.47 million km²) of forest, making it home to roughly 9% of the world’s forests.
The continental United States (the 48 contiguous states plus Washington, D.C.) has a total land area of about 7.66 million km².
Here’s the comparison:
| Area | Square kilometers | Square miles |
|---|---|---|
| Canadian forests | ~3.47 million km² | ~1.34 million mi² |
| Continental U.S. land area | ~7.66 million km² | ~2.96 million mi² |
So:
- Canadian forests are about 45% of the area of the continental United States.
- Put another way, you would need a little more than two Canadian forests to cover the contiguous U.S.
Zeke Hausfather in Climate Brink:
Canada’s area burned has surged, and it has surged in step with warming: hot, dry fire seasons burn far more forest, with area burned rises roughly 80% for each 1C increase in fire-season temperature (with a correlation coefficient of 0.61). This relationship is robust to a variety of statistical tests and controlling for confounding variables. The boreal burns in rare, high-intensity crown fires on a natural cycle measured in a century or more, across enormous remote areas that have never been logged, thinned, or effectively suppressed. Only about a fifth of Canada’s burned area over the past four decades was even inside forest regions that have ever been actively managed. You cannot have a fuel-buildup from forest mismanagement in a forest you were never managing.
Canadian fire seasons (May through September) have warmed about 2.2C on average since 1959. Canada warms at roughly twice the global rate, and its north at roughly three times. That warming matters for fire through a well-understood mechanism: warmer air is exponentially “thirstier” (saturation vapor pressure rises ~7% per degree), so it pulls moisture out of live vegetation and dead fuels alike, priming the landscape to burn. It’s the same fuel-drying pathway that Abatzoglou and Williams (2016) found had roughly doubled cumulative forest area burned in the western US.
Hanes et al. (2019), examining the Canadian record from 1959 to 2015, found fire seasons starting earlier and ending later, more days with conditions suitable for fire spread, and increases in both annual area burned and the frequency of large fires. They found that these trends were consistent with human-caused warming, not with changes in forest management (which have been broadly stable since the 1980s even as the fire seasons have gotten dramatically worse).
The pattern is hard to miss. The biggest fire years pile up in the hot-and-dry corner with 2023 really standing out, and the recent era (red dots, 2011–2025) has shifted visibly toward that corner relative to the black dots of the 1960s. Canada’s fire seasons are migrating into the part of weather-space where the big burns happen.
We can also try and more directly quantify the relationship between area burned and temperature. Nationally, fire-season temperature correlates with log area burned at r = 0.61 (1972–2025), which means that a fire season 1C warmer sees ~80% more area burned. I want to be careful about what this does and doesn’t show, so I stress-tested it: the correlation survives detrending (r = 0.57), first-differencing (r = 0.46), and partialling out precipitation (r = 0.58). It isn’t just two things drifting upward together, and it isn’t a rebranded precipitation effect.2
