How Climate Change is Altering Petrichor, the Glorious Smell after It Rains

The distinct, earthy smell that fills the air after rain following a long dry spell can trigger some serious nostalgia. This scent, petrichor, goes right to our brain's memory and emotional centers for reasons that may be to do with our very evolution. But as climate change alters Earth's weather and environment, petrichor is going to transform, too.

First, it helps to know why petrichor even happens. During dry periods, soil-dwelling bacteria produce a compound called geosmin that deters insects such as fruit flies. The chemical signals to the flies that the plant material the bacteria grow on isn't appetizing and that it might be toxic. Geosmin also attracts spore-spreading animals, such as springtails, which help disperse the compound even more widely.

"Humans are extremely sensitive to geosmin," said Johan Lundström, a psychologist specializing in olfactory perception at the Karolinska Institute in Sweden. "If there was one drop of geosmin stirred up into an Olympic-sized swimming pool, we’d still smell it."

Please select this link to read the complete article from Scientific American.