Australia’s disastrous 2019-2020 fire season blew so much smoke into the upper atmosphere that it blocked sunlight from reaching Earth’s surface, potentially causing a brief global cooling effect comparable to a moderate volcanic eruption, new research has found.

In late 2019 and early 2020, raging wildfires in southeastern Australia spawned a rash of rare fire-induced thunderclouds, known as pyrocumulonimbus clouds, or pyroCbs. This pyroCb “superoutbreak,” as scientists are now calling it, injected plumes of smoke into the stratosphere, a layer of the atmosphere that starts about nine miles overhead. There, the smoke plumes spun up their own winds, creating self-sustaining vortexes that circled the globe, in one case climbing to an unprecedented altitude of more than 20 miles in the process.

These smoke plumes did something else scientists weren’t expecting.

Australia’s fires blew smoke 19 miles into the sky, similar to a predicted nuclear blast

Findings published recently in Communications Earth & Environment and presented at the virtual American Geophysical Union (AGU) conference this week show that smoke acted like a planetary shade, reducing […]