How do forests cool themselves during the summer? This is what a recent study published in Agricultural and Forest Meteorology hopes to find out as a team of international researchers investigated the forests cool themselves through water evaporation and shading. However, climate change could have drastic consequences towards this type of natural air conditioning, specifically from droughts that dry up the soil, disabling a forest’s ability to stay cool during hot months.
For the study, the researchers collected daily measurements over four straight summer seasons of soil moisture and air temperature across 54 sites in broadleaf forests throughout Central Europe. They discovered that shaded forests were typically 2 degrees Celsius (36 degrees Fahrenheit) cooler than temperatures outside the shaded forests. Additionally, they discovered that this cooling effect was driven by soil moisture with this cooling effect becoming less prevalent as soils become drier.
“The findings are alarming in the context of climate change as more frequent and more severe droughts may threaten the cooling functions of forests,” said Dr. Caroline Greiser, who is a landscape ecologist at Stockholm University and lead author of the study.
This study comes as the World Health Organization estimates that approximately 55 million people around the world are impacted by drought, and as much as 700 million people could be displaced due to drought by 2030. Such increased levels of drought could result in forest soils not getting the moisture they need to maintain their natural air conditioning, especially as the summers temperatures continue to increase, with June 2023 being recorded as the hottest June ever.
How will climate change continue to impact forests and their natural air conditioning in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Agricultural and Forest Meteorology, EurekAlert!, World Health Organization, PBS News Hour
Featured Image: Image of trees providing shade from hot summer temperatures. (Credit: Josef Brůna)
