Far more than the flames that have engulfed southern Europe and North America in recent weeks, it is the smoke that dominates the astonishing death toll from combusting nature. Thick with toxic gases that inflame the airways and tiny particulates that breach the lungs and ride the bloodstream to hit every organ in the body, fumes from landscape fires kill 1.5 million people each year, a study in the Lancet found in 2024 – more than floods, flames, storms and heat combined.