abc
QUICK LINKS:

Study: Arctic Getting Darker, Making Earth Warmer

Created: 02/17/2014 2:17 PM WDIO.com
By: SETH BORENSTEIN, AP Science Writer

WASHINGTON (AP) - The Arctic isn't nearly as bright and white as it used to be because of more ice melting in the ocean, and that's turning out to be a global problem, a new study says.

With more dark, open water in the summer, less of the sun's heat is reflected back into space. So the entire Earth is absorbing more heat than expected, according to a study published Monday in the Proceedings of the National Academy of Sciences.

That extra absorbed energy is so big that it measures about one-quarter of the entire heat-trapping effect of carbon dioxide, said the study's lead author, Ian Eisenman, a climate scientist at the Scripps Institution of Oceanography in California.

The Arctic grew 8 percent darker between 1979 and 2011, Eisenman found, measuring how much sunlight is reflected back into space.

"Basically, it means more warming," Eisenman said in an interview.

The North Pole region is an ocean that mostly is crusted at the top with ice that shrinks in the summer and grows back in the fall. At its peak melt in September, the ice has shrunk on average by nearly 35,000 square miles - about the size of Maine - per year since 1979.

Snow-covered ice reflects several times more heat than dark, open ocean, which replaces the ice when it melts, Eisenman said.

As more summer sunlight dumps into the ocean, the water gets warmer, and it takes longer for ice to form again in the fall, Jason Box of the Geological Survey of Denmark and Greenland said in an email. He was not part of the study.

While earlier studies used computer models, Eisenman said his is the first to use satellite measurements to gauge sunlight reflection and to take into account cloud cover. The results show the darkening is as much as two to three times bigger than previous estimates, he said.

Box and University of Colorado ice scientist Waleed Abdalati, who was not part of the research, called the work important in understanding how much heat is getting trapped on Earth.

___

Online: PNAS journal

(Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)

NOAA photo

Front Page

  • General Mills Website Policy Could be 'Clicking' Your Rights Away

    Could clicking "like" on a company's Facebook page, entering their sweepstakes, or downloading their coupons cost you your right to take that company to court? Some consumer advocates are raising their eyebrows at the new website privacy policy for General Mills, saying it could do just that. 

  • 2 Hospitalized After Lincoln Park House Fire

    Two people are in the hospital after a house fire in Duluth's Lincoln Park neighborhood on Friday. Assistant Fire Chief Bryan Bushey said the damage is estimated at $30,000. There is no word on the conditions of the victims.

  • Aitkin Woman Dead in Wright Co. Crash

    An Aitkin woman is dead after a car crash near Minneapolis on Wednesday, according to the Minnesota State Patrol. 65-year-old Karen Tibbetts was driving an SUV that lost control on Highway 55 between Rockford and Buffalo.

  • Former Minn. Minister Accused of Abuse Reported in Spokane-area

    The Washington State Patrol says investigators have acted on 20 or 30 tips this week as they check locations in the Spokane-area in their search for a self-professed minister accused of sexually abusing at least two girls in rural Minnesota.

  • Smokehaus to Deliver Sandwiches, Meat by Bike

    The Northern Waters Smokehaus is looking to avoid traffic this summer by also going green. On May 5, they will begin delivering their sandwiches around downtown Duluth and down Park Point by bike.

 

Winter Weather Advisory

MN AREAS AFFECTED: Carlton, South St. Louis; Central St. Louis; North St. Louis
Expires: 4/19/2014 12:00 PM

Winter Weather Advisory

MN AREAS AFFECTED: Northern Cook, Northern Lake; Southern Cook, North Shore; Southern Lake, North Shore
Expires: 4/19/2014 4:00 PM

Flood Warning

MN AREAS AFFECTED: Aitkin; Crow Wing
Expires: 4/24/2014 7:00 AM

Advertisement
Advertisement
Advertisement
Advertisement