‘My Ideas Are a Little Revolutionary’: Ecologist Suzanne Simard on Intelligent Forests, the Climate and Her Critics

In 2018, the ecologist and writer Suzanne Simard was conducting research in the forested Caribou Mountains of western Canada when a thunderstorm rolled in. She was with her two teenage daughters and her close friend and colleague, Jean Roach. They saw flashes of lightning, heard a loud rumble and then they smelled smoke. They were forced to run the half kilometre back to Simard’s truck as the trees behind them caught alight and the air grew thick. As they ran, animals burst out of the forest: a deer, a rabbit, a grey wolf. They reached the truck with no time to spare, all four of them covered in soot and dirt. Overhead, helicopters began circling the orange-black air, dropping water on the flames below.

Wildfires have become an ever bigger problem in Canada. The 2018 wildfires were the biggest in British Columbia’s history, but this record was broken in 2021, and then again in 2023, when fires consumed an area three times the size of the Canadian province of Nova Scotia and the smoke travelled as far as New York City. The cause is not only global heating, which has brought hotter, dryer summers, but also the changing makeup of the forest. When logging companies clear forest, they replant it with fast-growing conifer species, but these trees are much more flammable than Canada’s diverse, native forest.

The country’s forests are so huge that for decades policymakers assumed that human activity would make little impact. “The rationale was that it will all come out in the wash: the trees will recover, the forests will grow back, and we’ll all be fine,” Simard says, speaking on a video call from Vancouver. But deforested areas do not fully recover, and thanks to logging, the wildfires and a devastating pine beetle outbreak, Canada’s forests, once a vast carbon sink, have since 2001 been a net emitter of carbon.