by Daniel Brouse
November 11, 2023
Feedback is the process in which changing one quantity changes a second quantity, and the change in the second quantity in turn changes the first. Positive feedback loops amplify the change in the first quantity.
Studies have found lightning and forest fires are creating a feedback loop. More lightning sparks a vicious cycle, as trees and soil set ablaze release warming CO2 creating more storms and more lightning.
The study Forests at Risk Due to Lightning Fires found a sensitivity of extratropical intact forests to potential increases in lightning fires, which would have far-reaching consequences for terrestrial carbon storage and biodiversity. The results show that, on a global scale, lightning is the primary ignition source of fires in temperate and boreal forests.
“What many people may not be aware of is that lightning is the most common ignition source for fires in remote temperate and boreal forests,” says Thomas Janssen, research associate at VU Amsterdam. These forests store large amounts of carbon, which is released in the form of greenhouse gases during the fire. The research reveals that 77 % of the burned area in intact forest regions outside the tropics is due to lightning fires, and the number of strikes is expected to increase by 11 to 31 % per degree warming with ongoing climate change.
“When a thunderstorm passes through this landscape, there are thousands of lightning strikes, and some hundreds of them start little fires,” said Prof Sander Veraverbeke from the Vrije Universiteit Amsterdam, one of the authors on the research paper. “And these can grow together into mega-fire complexes that become the size of small countries. Once these fires are so big, it becomes very difficult to do anything about them.”
Toppled Tipping Points: The Domino Effect / Brouse and Mukherjee (2023)