Fire danger in the high mountains is intensifying: That’s bad news for humans, treacherous for the environment
Retrieved on:
Wednesday, April 19, 2023
Human, Climate, Erosion, Farmer, Water quality, Tree, Sun, Fire, Research, Temperature, Absorption, Burn, Forest, Snow, Biodiversity, Sierra, The, Risk, Water, Groundwater, Hydrology, Continental Divide of the Americas, City, Ecology, Safety, Coal, Silviculture, Dam
The following year, California’s Dixie Fire became the first on record to burn across the Sierra Nevada’s crest and start down the other side.
Key Points:
- The following year, California’s Dixie Fire became the first on record to burn across the Sierra Nevada’s crest and start down the other side.
- High mountain fires can create a cascade of risks for local ecosystems and for millions of people living farther down the mountains.
- Since cooler, wetter high mountain landscapes rarely burn, vegetation and dead wood can build up, so highland fires tend to be intense and uncontrollable.
Four decades of rising fire risk
- This enabled fire managers to leave fires that move away from human settlements and up mountains to run their course without interference.
- We analyzed fire danger trends in different elevation bands of the Western U.S. mountains from 1979 to 2020.
- Over that 42-year period, rising temperatures and drying trends increased the number of critical fire danger days in every region in the U.S. West.
- In previous research, we found that high-elevation fires had been advancing upslope in the West at about 25 feet (7.6 meters) per year.
Cascading risks for humans downstream
- High-elevation fires can have a significant impact on snow accumulation and meltwater, even long after they have burned out.
- The result of these changes can be spring flooding, and less water later in the summer when communities downstream are counting on it.
- This can trigger mudslides and increase the amount of sediment sent downstream, which in turn can affect water quality and aquatic habitats.
Hazards for climate-stressed species and ecosystems
- Since they don’t burn often, their ecosystems aren’t as fire-adapted as lower-elevation forests, so they may not recover as efficiently or survive repeated fires.
- Wet mountain areas, with their cooler temperatures and higher precipitation, are often peppered with hot spots of biodiversity and provide refuges to various species from the warming climate.
- While the risk is rising fastest in the high mountains, most of the West is now at increasing risk of fires.