Forest fires release far more polluting gases than previously estimated. Many of these emissions are hidden and can turn into fine particles that are dangerous to breathe. Carbon dioxide from forest fires is a growing source of greenhouse gas emissions worldwide, reaching approximately 8.6 billion tons last year[1]. In some parts of the world, the pollution caused by forest fires equals emissions caused by human activity. Smoke from wildfires can linger and worsen air quality long after the flames have died down. Toxic substances from forest fires have penetrated the homes of more than a billion people in the last twenty years[6]. Air pollution from wildfires alters immune cells and causes allergies and asthma[5].