The images are wild. So much of Australia burned, that the smoke will likely “make at least one full circuit around the globe, returning once again to the skies over Australia.”
NASA:
The fires in Australia are not just causing devastation locally. The unprecedented conditions that include searing heat combined with historic dryness, have led to the formation of an unusually large number of pyrocumulonimbus (pyrCbs) events. PyroCbs are essentially fire-induced thunderstorms. They are triggered by the uplift of ash, smoke, and burning material via super-heated updrafts. As these materials cool, clouds are formed that behave like traditional thunderstorms but without the accompanying precipitation.
PyroCb events provide a pathway for smoke to reach the stratosphere more than 10 miles (16 km) in altitude. Once in the stratosphere, the smoke can travel thousands of miles from its source, affecting atmospheric conditions globally. The effects of those events -- whether the smoke provides a net atmospheric cooling or warming, what happens to underlying clouds, etc.) -- is currently the subject of intense study.