A Drier Alaska: Our Scientists Identify the Areas to Be Hit Hard by Climate Change

November 30, 2009 By Christine Soliva

Caribou in Izembek National Wildlife Refuge. Photo by John Sarvis, Courtesy USFWS.

Climate change may cause Alaska’s growing season to become about 80 percent drier by mid century, causing profound effects on wildlife, vegetation and human communities, according to new research conducted by our climate change analyst Brendan O’Brien, and ecologist Wendy Loya.

By the end of the century — or 2094 according to our estimates — that same growing season may become a whopping 200 percent drier in a state already impacted by climate change.

Our scientists made the projections after developing a tool to map changes in Alaska’s water availability in an effort to help land managers, scientists and others identify lands and species most vulnerable to change.

We found that as temperatures continue to rise due to climate change, Alaska’s growing season is projected to become warmer and drier with significantly more water leaving the landscape due to higher evaporation and transpiration rates than incoming precipitation.
To estimate changes in growing season water availability, we used forecasted temperature and precipitation data from Global Circulation Models (GCM’s) to calculate the difference between precipitation, and evaporation and transpiration over the next century.

After developing the tool, we determined that Alaska’s Western Arctic and Aleutian Meadows ecoregions are expected to undergo the most serious water shortages in the future, becoming roughly 250 percent and 120 percent drier by 2094, respectively.

The Western Arctic is home to hundreds of thousands of caribou which will undoubtedly be forced to adapt to these changes. If the historic migration of the herd is impacted, suffering may spread through the indigenous people who depend on the herd for their dietary needs and cultural heritage, as well as the commercial operators that provide services to caribou hunters.

The Aleutian Meadows region includes the Izembek National Wildlife Refuge. Increased water shortages in the Refuge will make life difficult for millions of migratory waterfowl that stop at the Refuge to seek food and shelter on their way to and from their arctic breeding grounds.

Already in Alaska, increases in temperature and changes in precipitation have had profound effects on regional hydrology, including shrinking wetlands, glacier and polar sea ice recession, permafrost melting, and an increase in fire frequency and intensity across the landscape as a result of increased drought and thunderstorms. In Alaska’s northern climate, most of the precipitation falls during winter months, when it accumulates in the snowpack and contributes to water storage across the landscape.

By supplying scientists, land managers, conservationists, and members of the public with a tool for understanding changes in future water availability, we’ll be better prepared to identify species, landscapes or communities that are particularly vulnerable to change. Once connections between the hydrologic characteristics of a region and the natural and cultural resources have been established, stakeholders can focus on developing the most effective measures to facilitate successful adaptation.

photos:
Caribou in Izembek National Wildlife Refuge. Photo by John Sarvis, Courtesy USFWS.
Canada Geese flying in Izembek Lagoon. Photo by John Sarvis, Courtesy USFWS.