A study examines accelerated burning of Rocky Mountain forests. The western United States has experienced increased wildfire activity in recent years. To understand the causes and consequences of extreme fire seasons, particularly in forests with historically infrequent fires, Philip Higuera and colleagues examined 20 previously published fire reconstructions in the central Rocky Mountains spanning the last 2,000 years. Charcoal from lake-sediment records primarily aided the reconstructions. The authors also examined 1984-2020 US government records of fire activity. Since 1984, the burnt area across the central Rocky Mountains has increased significantly. In high-elevation subalpine forests of the central Rocky Mountains, wildfires that occurred in 2020 accounted for 72% of the total burnt area since 1984. Current burning rates are higher than at any point over the past 2,000 years, including during the early Medieval Climate Anomaly (MCA) of 770-870 CE, when the Northern Hemisphere's average temperature was higher than it was during the 20th century. Increasingly warm, dry conditions, the authors note, are enabling accelerated rates of forest burning. As average 21st-century temperatures continue surpassing those of the MCA, the Rocky Mountains are likely to experience continued acceleration of wildfire activity for at least several decades, according to the authors.
Article #21-03135: "Rocky Mountain subalpine forests now burning more than any time in recent millennia," by Philip E. Higuera, Bryan N. Shuman, and Kyra D. Wolf.
MEDIA CONTACT: Philip E. Higuera, University of Montana, Missoula, MT; tel: 406-599-8908; email: <firstname.lastname@example.org>
Proceedings of the National Academy of Sciences