What turned California forests into a tinderbox? Fire suppression, paradoxically

Before this unprecedented era of mega-blazes on the US west coast, California’s forests had a canny, ingenious way of avoiding destructive worst-case forest fire scenarios. By periodically removing the grasses, shrubs and young trees – known as the forest understory – California avoided fires growing to destructive intensities before the 20th century. The way this was done? Fire.