The Impacts of Disappearing Snow

Project overview: Research and map snow fields and ice patches in the park to understand how their loss, due to climate change, will affect the park and areas downstream that rely on Yosemite’s water.

How your support helps: One of the most direct and visual impacts of climate change in Yosemite is the disappearance of year-round snow and ice features. Although the park’s two glaciers have been studied extensively for more than a century, much less is known about the current state of perennial snow and ice patches in the park.

A previous Yosemite Conservancy–funded project studied the contribution of the last remaining glaciers to the Tuolumne River’s flow, concluding that more than 70% of late-summer flow in dry years comes from glacial melt. However, glaciers are not the only source of melt water in the park, which has many more year-round snow and ice patches not considered “glaciers.” Despite this, they also cumulatively contribute a large percentage of flow to Yosemite’s streams and rivers, particularly in drought years and during late summer and fall.

Scientists estimate glaciers in the park will disappear completely in the next couple of decades due to climate change. This likely holds true for the year-round snow and ice, as well, though we do not currently know how much there is, where these patches are located, or how much streamflow they generate.

Understanding the significance of year-round snow and ice patches, and to what extent they contribute to Yosemite’s streams and species habitat, will inform park managers on how their loss will ripple through alpine ecosystems.

This year: In 2022, researchers will use aerial imagery to map the extent of perennial snow and ice patches in Yosemite, measure their contribution to late-season runoff, and explore how their disappearance might affect dependent species. This will allow park managers to adapt to shifting water resources in a changing climate.

Project partner: Yosemite National Park