Climate Change Insights from Military Air Samples

Scientists at Lund University in Sweden have found significant evidence of climate change by examining decades-old air samples collected by the Swedish Armed Forces. These air samples, initially gathered to monitor radioactive fallout from nuclear weapons testing, revealed changes in the seasonal release of moss spores over the last 35 years.

The research indicates that moss spores are now released about four weeks earlier than they were in 1990, with the peak of spore dispersal occurring roughly six weeks sooner. Nils Cronberg, a botany researcher at Lund University, highlights the considerable difference in timing, especially given the short summers in northern regions.

The study points to warmer autumns as a crucial factor, as higher autumn temperatures allow mosses more time to develop spore capsules before winter. Interestingly, the researchers found that climate conditions from the previous year had a more significant impact on spore timing than spring weather or snow thaw in the same year.

This research not only documents rapid ecological responses to climate change but also introduces a new method for tracking long-term ecological changes using DNA from air samples. The findings could contribute to future reports by the Intergovernmental Panel on Climate Change, providing valuable insights into how nature has shifted since the 1970s.

The research was led by Per Stenberg from Umea University and Fia Bengtsson, formerly of Lund University, now at the Norwegian Institute for Nature Research.