US President Donald Trump accused Canada of 'wilful negligence' over wildfires, blaming its forest management, threatening tariffs and floating demands for compensation.
Smoke, however, does not carry a passport. Wildfires are currently scorching vast areas in Oregon and the Pacific Northwest, and in Europe, France and Spain have evacuated hundreds of thousands of residents as wildfires close in on Bordeaux and grow around Madrid.
In Canada, lightning is responsible for most of the area burned. A 2004 study demonstrated that human-caused climate change had already left a detectable fingerprint on the area burned by Canadian forest fires. A 2024 study found that human influence has made fire seasons like Canada’s record 2023 season more than five times as likely across nearly every Canadian ecozone.
The United States has emitted more cumulative fossil carbon dioxide than any other country. Trump withdrew the US from the Paris climate agreement while promoting fossil-fuel expansion. Canada remains one of the world’s highest per-capita emitters of greenhouse gases.
The US National Oceanic and Atmospheric Administration gives El Niño an 81 per cent chance of becoming very strong from October through December and a 97 per cent chance of persisting into early spring 2027.
Stopping the escalation requires geological net zero: cutting fossil carbon emissions as far as possible and permanently returning an equivalent amount of any residual fossil carbon to geological storage.