Left image
View of Mt. Diller and Lassen Peak on April 1, 2012 with 82% of average snow depth winter snowpack; taken from a lower perspective.
Right image
A rare winter sight of Mt. Diller and Lassen Peak without snow on January 19, 2014; taken from Brokeoff Mountain summit.
Lassen Volcanic's climate is experiencing shifts as a result of human-caused climate change. These changes are resulting in significant impacts including warmer temperatures, earlier spring snowmelt and increased drought, and wildfire frequency and severity and tree mortality. Lassen Volcanic is actively working to address the challenge of climate change starting with identifying and preparing for a range of possible future conditions and related vulnerabilities of park resources.
Average temperature increased for 1895-2021 and at a faster rate for 1971-2021. Annual precipitation decreased slightly for 1971-2021. Gray shaded area around regression lines is standard error of predicted years: Reference Period 1900-1970, Recent Period 1971-2021, and Overall Period 1895-2021.
Warmer Temperatures
Maximum, minimum, and average temperatures in the park have increased significantly between 1895 and 2021. Temperatures between 1971 and 2021 increased at rate of about 4º per century.
Precipitation has not increased between 1895 and 2021. Surprisingly, climate modeling suggests precipitation could increase within the park. Even if this is the case, temperature increases may lead to increased evaporation resulting in decreased soil moisture.
Annual average temperature in the park could see increases up to 4.6ºC (8.3ºF) from 2000 to 2100.
Drought-level heat may occur at the same time as the park dry season each year by 2030.
Continued increases in winter and spring heat may reduce snowpack by up to two-thirds.
Warmer temperatures may reduce the number of snow days in the Sierra Nevada by 1/3 from 2005 to 2050 (under the highest emissions scenario).
Drought conditions in October 2021 left the Butte Lake swimming and fishing area and boat launch high and dry. Willow roots at left indicate normal lake level.
A snowpack survey location marker (outlined in yellow) near Lassen Peak on April 30, 2021. Snow depth measured 91.5 inches, 52% of April average. Snowpack measurements have been recorded here since 1930.
NPS
Reduced Snowpack
Water from Lassen Volcanic flows through four watersheds that provide the state with water. Rapid changes in climate over the last few decades have resulted in reduced snowpack, warmer wintertime temperatures, and earlier spring melt, which deplete these crucial snow-based reservoirs. Data from weather stations and snowpack surveys shows changes in snow resulting from increased heat of climate change:
Snow-covered declined by 1/5in the southern Cascades and northern Sierra Nevada from 1950 to 1999.
Water content of snowpack declined 10-20% across the western US between 1982 and 2016.
The California Drought of 2011-2016 resulted in Lake Helen snowpack depths that were as low as 52% of average (March 2015). The five-year drought was initiated by a low period in the natural precipitation cycle and intensified by the record heat of human-caused climate change. Future climate models project an increase of total annual precipitation within the park, however hotter temperatures would reduce snowpack and raise the probability of drought.
The 2021 Dixie Fire is the largest fire in park history. Its footprint covers 69% of the park, including large portions of the Mill Creek drainage in the Southwest Area.
More Fire
The increased heat of climate change has intensified drought, reduced snowpack, and caused spring warming to occur earlier. As a result, forests that are dry earlier and for longer periods of time are driving the increase in wildfires.
Data for the Sierra Nevada and southern Cascades regions show fire was controlled by summer drought severity and precipitation in the preceding year’s winter. Analyses of climate and wildfire across the western United States, including data from Lassen Volcanic, found that climate change doubled the area burned by wildfire from 1984 to 2015 compared to what would have burned without climate change.
Lassen Volcanic is continuing its 30-year history of managing fire to restore its role as a natural ecosystem process while reducing threats to human health, safety, and property. Firefighting is also changing to address the increasing frequency and severity of wildfire as exemplified by the 2021 Dixie Fire. Firefighting activities are increasingly focused around developed areas to protect life and structures and firefighters have shorter windows in which to complete proactive fire management strategies.
Top to bottom: A northern spotted owl, a Cascades frog, and an American pika.
Top to bottom: NPS/Wayne Steffes, NPS/ORCA, USFS/Shane Jeffries
Effects on Wildlife
Changes in wildlife can impact animal habitat and individual species' ability to thrive within the park. Projected increases in fire frequency could expand shrubland and reduce mixed conifer forest, altering habitat for plants and wildlife. Research highlights vulnerabilities to warmer temperatures and increased drought in a number of park animals including owls, frogs, fish, bats, owls, and rodents.
Northern spotted owl (Strix occidentalis caurina) habitat could be reduced by potential changes in forest cover due to wildfire, bark beetle infestations, and shifts in flora and fauna within habitats (biome shifts). Field research found that survival of young northern spotted owls in California, Oregon, and Washington was most highly correlated to low winter temperature and precipitation.
The Cascades frog (Rana cascadae) is highly vulnerable to increased mortality due to drought. Drying ponds and meadows can strand eggs, tadpoles, and adult frogs. Surveys in the park haven't found the Cascades frog since 2008.
Coldwater fish are vulnerable to loss of suitable habitat due to potential warming of streamwaters.
Increasing dryness (aridity) can reduce bat reproduction. Their small body size and large surface area puts them at greater risk of dehydration, compared to other mammals.
Increased temperature and precipitation could increase the risk of plague in rodents in the park up to 80% by 2050, double the current risk.
Warming temperatures may substantially reduce habitat for Belding's ground squirrel (Urocitellus beldingi).
Pikas in Peril?
The American pika (Ochotona princeps) has a high body temperature and relies on crevices and cavities in rocks to provide cover and cool shade. Long-term monitoring in 8 national parks suggests that pika populations will decline and possibly go extinct in several parks by the end of the century as a result of decreasing habitat connectivity, increased temperatures, and altered precipitation.
Surveys in Lassen Volcanic suggest its numerous connected boulder fields and lava flow habitats may offset the stresses of climate change, and allow pikas to persist. Research shows that the number of pika within the park is supported by the arrangement and connection of habitat patches, rather than elevation. Although Lassen Volcanic is predicted to get warmer in the coming decades, models suggest that the population will increase by expanding into nearly all potential habitat (talus and lava). View results of pika monitoring between 2011-2016 within Lassen Volcanic.
Red fir forest covers the majority of the Southwest Area, while whitebark pine are one of a few species that grow in the subalpine zone above 8,000 feet.
NPS
Effects on Forests
Forests in Lassen Volcanic store as much carbon as what approximately 600,000 Americans emit in one year. Unfortunately, park forests are experiencing significant mortality from a combination of threats including increased drought, wildfire, and pathogens like beetles and blister rust. Lassen Volcanic is working to protect vulnerable tree species through monitoring, research, and management actions when necessary and appropriate.
Drought, Beetles, and Rust
Monitoring in forest plots across the western U.S., including plots in the park, found a doubling of tree mortality rates between 1955 and 2007. The increased rate of mortality was due more to the heat of climate change, increased wildfire, and bark beetle infestations; than to other factors.
Researchers have been monitoring whitebark pine (Pinus albicaulis) at Lassen Volcanic and Crater Lake for over a decade to track infection and death rates from the non-native fungal pathogen blister rust (Cronartium ribicola), mountain pine beetle, and other stressors such as fire. Monitoring shows a gradual, but striking decline in the species across the park.
Mountain pine beetles (Dendroctonus spp.) affect any pine species including Jeffrey pine (Pinus jeffreyi), sugar pine (Pinus lambertiana), and western white pine (Pinus monticola). Increased periods of drought could increase the trees' susceptibility to this native pathogen.
White fir (Abies concolor) are increasingly susceptible to the fir engraver beetle during periods of drought. High-incidence morality from the 2011-2016 California drought is visible throughout the park on steep north-facing slopes.
Lassen Volcanic continues to reduce emissions from park operations and provide opportunities for visitors to support sustainability within the park.
NPS
Helping to Reduce Greenhouse Gas Emissions
Lassen Volcanic is one of numerous Climate Friendly Parks that are committed to addressing climate change and supporting the most sustainable operations throughout the park. The park's action plan identified greenhouse gas (GHG) reduction goals in four categories: energy, transportation, waste, and total park emissions.
The largest emission sector for Lassen Volcanic is transportation, which totals 84% of park emissions. The park's remote location and outlying roadways present challenges to reduce transportation-related GHGs, however the park is working to encourage growing electric vehicle among park visitors. Lassen Volcanic installed two level-2 charging stations in the Southwest Area in 2021 and is moving forward with plans to install additional stations in the Manzanita Lake Area in the near future.
Lassen Volcanic supports efforts to use less and recycle more through numerous sustainability efforts including:
