When Siberian volcanoes kicked off the Great Dying, the real climate villain turned out to be the rainforests themselves: once they collapsed, Earth’s biggest carbon sponge vanished, CO₂ rocketed, and a five-million-year heatwave followed. Fossils from China and clever climate models now link that botanical wipe-out to runaway warming, hinting that losing today’s tropical forests could lock us in a furnace we can’t easily cool.