Canada wildfire smoke live updates: Poor air quality affects millions

Richard Gray

Editor, BBC Future

While wildfires can devastate the land, wildlife, homes and lives of people caught up in the flames, the smoke can travel around the world.

Ash, smoke and even burning material can be carried upwards by super-heated updrafts, creating a type of fire-induced thundercloud known as a pyrocumulonimbus.

These allow the thick plumes that belch from large wildfires to rise up to 14 miles (23km) into the air, reaching into the stratosphere. Air currents can then carry this smoke over vast distances, crossing entire continents and even oceans to affect air quality far away from the flames themselves.

In 2019, pollution billowing from forest fires in Alberta, Canada, spread down the east coast of the US, across the Atlantic Ocean and into Europe.

The devastating bushfires in Australia in January 2020 produced some of the largest pyrocumulonimbus clouds ever recorded, leading to smoke turning the skies in South America hazy.

These satellite images taken by NASA and the National Oceanic and Atmospheric Administration show the extent of the current Canada wildfire smoke.