The emissions, called secondary organic aerosols, are at their worst during hot, sunny weather, according to the study conducted in southern California.

Smoke from burning cities would release 16 to 36 teragrams of black carbon into the atmosphere, blocking out sunlight and cooling the global surface.

Progress toward a universal flu vaccine, social and behavioral interactions among astronauts, indoor air pollution, and racial bias within the criminal justice system will be discussed at the 2019 American Association for the Advancement of Science (AAAS) Annual Meeting, the world’s largest general scientific conference.