Future Climate and Water Availability in Alaska

Kirsten Feifel Rachel M. Gregg
Posted on: 12/31/2009 - Updated on: 10/28/2021

Posted by

Kirsten Feifel

Project Summary

Climate change is evidenced in Alaska by shrinking glaciers, warming temperatures, and increases in fire frequency and intensity. The Wilderness Society has created maps of Alaska highlighting expected changes in temperature, precipitation, and water availability to help inform land managers and to prioritize restoration and protection activities that enhance ecosystem resilience.


In Alaska, evidence of climate change, such as warmer temperatures and changes in precipitation patterns, already exists. To help land managers make informed decisions regarding future hydrological conditions, The Wilderness Society in collaboration with The University of Alaska-Fairbanks’s Scenarios Network for Alaska and Arctic Planning (SNAP) program developed a tool for mapping future water availability across the state. It is their hope that these maps will aid decision makers in identifying areas that are particularly vulnerable to change and allow them to instill proactive measures to help areas adapt.


To evaluate changes in the hydrological cycle and water availability, monthly potential evapotranspiration (PET) and precipitation (P) were estimated using the Preistley-Taylor method on five downscaled global climate models. The Preistley-Taylor method utilizes vegetation cover and climate information: mean monthly temperature, maximum and minimum monthly temperatures, and percent cloud cover to estimate monthly PET rates. The difference between PET and P provides a relative index of water availability on terrestrial lands. In general, climate change is expected to reduce the amount of water available in Alaska by 10-30%, particularly during the peak growing month of June. A dramatic decrease in water availability will have massive effects on wildlife, vegetation, and cultures reliant upon permanent sources of water.

Outcomes and Conclusions

Alaska’s freshwater resources are threatened by global climate change. By demonstrating changes in future water availability, project leads hope to help managers and planners identify and protect species, habitats, and communities that are acutely vulnerable to these changes. Climate and hydrologic monitoring needs to be enhanced in scope and accuracy in order to create useful predictive analyses for managers and planners.


Feifel, K. and Gregg, R.M. (2020). Future Climate and Water Availability in Alaska [Case study on a project of The Wilderness Society and University of Alaska-Fairbanks]. Version 2.0. Product of EcoAdapt's State of Adaptation Program. (Last updated March 2020)

Project Contacts

Affiliated Organizations

The wilderness society was established in 1935 with a founding mission to “protect wilderness and inspire Americans to care about our wild places.” To date notable accomplishments include writing and passing the Wilderness Act and protecting 109 million acres of land as designated Wilderness, over half of which is in Alaska. Projects are completed using the best available science and in collaboration with communities and conservation groups. Their key issues include: wilderness, global warming, energy, roadless forests, and stewardship.

The University of Alaska-Fairbanks includes seven campuses across the state and is home to more than 11,000 students from all over the world.

Related Resources

Adaptation Phase
Sharing Lessons
Sector Addressed
Climate Justice
Conservation / Restoration
Culture / Communities
Disaster Risk Management
Education / Outreach
Land Use Planning
Rural / Indigenous Livelihoods
Transportation / Infrastructure
Water Resources
Read more