The Australian bushfires of 2019 produced so much smoke, it entered the stratosphere, 19 miles above Earth!

On an earlier episode, we talked about how fires make their own weather. As a column of hot air rises from the flames, it carries smoke into the atmosphere where it forms clouds.

Water vapor may condense around smoke particles and rain down to quench the fire. Or lightning may form in the clouds, which could cause more fire risk.

The Australian fires produced 100 million tons of smoke. The updraft was so strong, it carried this smoke up through the troposphere—the lowest layer of our atmosphere where weather occurs—and into the stratosphere.

The stratosphere is less turbulent than the troposphere, so particles tend to hang around much longer; the Australian smoke plume lasted for more than 6 months. It was vast enough to be seen easily from the space station.

Previous ash and aerosol clouds have entered the stratosphere from volcanic eruptions and other fires. These have cooled the planet by as much as 1 degree Fahrenheit by reflecting sunlight. Or warmed it by as much as 2 degrees by absorbing sunlight.

Scientists are still studying the Australian smoke plume to better understand these cooling or warming effects—and the potential impacts if humans were to introduce particles into the stratosphere to try to moderate Earth’s temperature in what’s called geoengineering.