The wildfires that raged in northwest America last August were so ferocious that they had the same effect on the planet as a volcanic eruption.

The heat and smoke from the fires led to the formation of massive thunderstorms known as pyrocumulonimbus . These storms, called pyroCbs for short, pumped the smoke from the fires so high in the atmosphere that it spread over the entire northern hemisphere and remained there for months, until November and December.

It was by far the largest event …