EESA climate scientists contributed to the stunning discovery that lightning strikes will increase by 100% this century above the Arctic Circle, where lightning is practically unheard of, due to climate warming. A paper published today in the journal Nature Climate Change describes how such an increase in lightning will drive further warming and wildfires across the region.
Berkeley Lab Research Scientist Zelalem Mekonnen and Senior Scientist Bill Riley are among the paper’s co-authors; as is EESA Faculty Scientist David Romps, whose previous work predicted a 50% increase in lightning strikes across the country this century due to warming from climate change. A 2019 paper by Mekonnen and Riley, which found that Alaska’s iconic evergreen conifer trees would be pushed out in favor of broadleaf deciduous trees in a warmer climate with more wildfires, was also of relevance to the new UC-Irvine led research.
“In our study of Alaska forests we found that boreal forest dynamics were controlled by interactions between wildfire, climate warming, nutrient availability, and plant traits affecting regrowth,” said Mekonnen. “This new paper illustrates how an increase in lightning strikes could exacerbate wildfire frequency. These fires would strip away protective layers of moss and dead organic matter that insulate perennially frozen soils which define much of the Arctic. The worry is that with thawing permafrost there could be planet-warming greenhouse gases released into the atmosphere to drive even more warming.”
The new research led by Yang Chen of UC-Irvine is the first to estimate how lightning is changing in this high-latitude region. Inspired by the finding that 2015 was a record year for wildfires in Alaska, Chen’s team set out to model 21st-century lightning strikes as a function of a rise in rainfall resulting from warming-driven evaporation, using a 20+-year NASA satellite dataset on Arctic lighting strikes.
The consequences of a surge in lightning strikes are intense: The researchers believe that their findings provide a glimpse into the changes in store for high latitudes as the planet continues to warm, and even anticipate Arctic weather conditions closer to those seen today in the middle of the U.S. where lightning storms are commonplace.
The work, funded by the U.S. Department of Energy, NASA’s Interdisciplinary Science and Carbon Monitoring System programs, and the Next Generation Ecosystem Experiment Arctic project, includes researchers from the University of California Irvine, University of California, Berkeley; Lawrence Berkeley National Laboratory; Harvard University, and Vrije Universiteit Amsterdam.