Alaska's sea ice and glaciers will keep shrinking, report predicts
May 7, 2014
Yuri Bult-Ito
907-474-2462
5/7/2014
Alaskans will see less sea ice, smaller glaciers and more fires as the climate changes in the coming decades, according to a climate review released this week.
The Third National Climate Assessment Report, from the U.S. Global Change Research Program, describes the climate’s current status and projects its future. University of Alaska Fairbanks researchers were among the 60 members who served on the advisory committee that developed the 30-chapter report.
John Walsh, chief scientist at the UAF International Arctic Research Center, served as a lead author on the climate science chapter. Terry Chapin, professor emeritus at the UAF Institute of Arctic Biology; Sarah Trainor, IARC’s Alaska Center for Climate Assessment and Policy director; and Dave McGuire, IAB professor, were lead authors on the Alaska chapter.
Climate change will strongly affect Alaska Native communities in particular, the Alaska chapter said.
Oceans around Alaska will see several changes, according to the Alaska chapter. Summer sea ice is receding and is projected to disappear by mid-century. In addition, more shrinkage of glaciers in Alaska and British Columbia will contribute to sea level rise. Increases in ocean temperatures and changes in ocean chemistry will affect marine fisheries, the researchers concluded.
Thawing permafrost in Alaska will cause drier landscapes and more wildfire. The thawing also will release heat-trapping gases.
The climate assessment also discusses whether humans have caused the changes.
“That is a tricky challenge,” Walsh said, because there has been no real warming of the global temperature in the past 15 years. “If greenhouse gas is supposed to be warming the planet, why has the temperature leveled off for the last 15 years?”
Heat uptake by the oceans and natural variability are key reasons the land surface has experienced little warming for the past 15 years, according to the report. It also discusses how these factors have the potential to cause a period of stronger warming in the near future.
The climate science chapter on which Walsh worked said with “high confidence” that the United States is warming and, while the eastern and northern regions have been wetter, the southwestern region has been drier. In addition, the hottest days are getting hotter, and coldest days are getting less cold, a trend also seen in Alaska. Heavy rain and snow events also are increasing, along with flooding.
The National Climate Assessment is required by the Global Change Research Act, which Congress passed in 1990.
ON THE WEB: http://nca2014.globalchange.gov.
ADDITIONAL CONTACTS: John Walsh, 907-474-2677, jwalsh@iarc.uaf.edu (the climate science chapter), or Dave McGuire, 907-474-6242, admcguire@alaska.edu (the Alaska chapter). Marmian Grimes, UAF information officer, 907-474-7902, mlgrimes@alaska.edu.
YB/5-7-14/309-14