Canada’s managed forest is one of the largest living reservoirs of carbon on the planet. For centuries it slowly filled, as billions of growing trees pulled CO2 from the air and stored it away in their wood. This ancient, continent-spanning, “carbon sink” helped keep the climate calm and cool. But in the last couple of decades, the flow of CO2 has completely reversed. Chainsaws and fossil fuel pollution are cranking open the floodgates that hold back this enormous reservoir of forest carbon. What started as a trickle a couple of decades ago has turned into a flood. Billions of tonnes of CO2 that were locked away in the forest have already drained back out on the backs of logging trucks and in the swirling smoke of ever more monstrous wildfires. This outpouring of forest carbon back into the atmosphere now dwarfs the fossil fuel emissions of most nations.