Snow and Ice

Snow avalanches alter mountain environments and have both beneficial and harmful effects on wildlife. Avalanches can benefit wildlife by creating open areas for grazing but can also be deadly when animals are buried in avalanche debris. Avalanches pose high risks to mountain goats because they inhabit rugged and steep terrain, but the actual impacts of avalanches on mountain goats remain...

Mountain meadows in the western United States provide key habitats for many plant and wildlife species, many of which rely exclusively on these areas. Mountain meadows are also treasured by the public and provide beautiful areas to view wildflowers and wildlife on public lands such as national parks. However, mountain ecosystems are expected to be disproportionately affected by climate...

Stream flow is directly tied to climate, and numerous studies provide substantial evidence that climate change is a threat to future aquatic water flow processes. In the southwestern United States, mountain snow is a primary water source for streams and rivers. However, climate change is threatening the region's mountain snow, leading to reduced snowpack, earlier snowmelt, and more...

Rain-on-snow events occur when warm rain falls on an existing snowpack, causing rapid snowmelt that can lead to damaging floods, reduced spring and summer streamflow, and altered stream temperatures, with ecological, social, and economic consequences. Rain-on-snow events can result in a loss of riverine biodiversity, decreases in fisheries production, and degradation of stream habitat...

High latitude northern ecosystems are currently warming twice as fast as the global average. Over the last several decades, this has caused dramatic losses of frozen area in the Arctic and sub-Arctic. However, it is unclear how melting coastal mountain glaciers, thawing permafrost, and declines in snowpack will affect the quality of freshwater habitat for culturally and economically...

Understanding the paths by which water flows through the landscape is critical for providing fresh water for human use, maintaining ecosystem function, and better predicting how disturbances such as fire or drought may impact water quantity and water quality. Yet projected changes in climate, disturbances, and land use, are likely to alter hydrologic flow paths, and natural resource...

Retreating glaciers are an iconic image of climate change;yet not all glaciers in Alaska are actively retreating, and a few glaciers are even advancing. While this contrasting behavior can be misleading for the casual observer, variable responses between glaciers in a changing climate are expected. Glaciers act as conveyor belts that transport snow and ice from high elevations, where it...

Major floods in Southeast Alaska and Hawaiʻi that potentially threaten life, property, and culturally significant resources and ecosystems are caused by mechanisms related to intense precipitation for both locations as well as snow melt-based processes for Alaska. Small, high-gradient, and heavily vegetated watersheds with direct contribution to the ocean are common in both locations. To

One of the most visible signs of climate change is less mountain snow. In the Western U.S., deep snow has historically been a cornerstone of life for many plants and animals. For example, snow can provide denning shelter for certain species like the wolverine, and snowmelt provides dependable water to mountain streams that are home to fish like the bull trout. Yet snow losses driven by...

In the Western U.S., approximately 65% of the water supply comes from forested regions with most of the water that feeds local rivers coming from snowmelt that originates in mountain forests. The Rio Grande headwaters (I.e. the primary water generating region of the Rio Grande river) is experiencing large changes to the landscape primarily from forest fires and bark beetle infestations...

Ongoing climate change is impacting areas of snow and ice in high latitudes and high elevation areas and is thus anticipated to change the frequency and magnitude of snow and ice related hazards. In Alaska, snow avalanches are the deadliest natural hazard, and they affect a large portion of the state, significantly impacting the natural landscape, the built environment, and public safety...

In the Gulf of Alaska, streams will experience more dramatic low water events, interspersed with larger and potentially more frequent high flow events in the coming decades. Reduced stream flows are likely to occur due to diminished snowpack and seasonal droughts, while higher flow events are likely to occur with more frequent storms and rain-on-snow events. These changes are likely to...