Old air samples hint at effects of climate change

Published 4 December 2025

Through the DNA analysis of old air samples collected by the Swedish Armed Forces, researchers at Lund University in Sweden can show that spore dispersal of northern mosses has shifted over the past 35 years. It now starts several weeks earlier, revealing how quickly nature’s calendar can reset in line with a warmer climate.

When the Swedish military began collecting air samples in the 1960s to register radioactive fallout from nuclear weapons testing, it is highly unlikely that anyone was thinking about moss. However, the glass fibre filters on which the samples were saved also captured something completely unintended – namely DNA from pollen, spores and other biological particles. This discovery was made by researcher Per Stenberg of Umeå University.

“The samples have proved to be an unexpected, unique and very exciting archive of DNA from wind-dispersed biological particles,” says Nils Cronberg, researcher in botany at Lund University end BECC PI.