Study: Arctic getting darker, making Earth warmer

Study: Arctic getting darker, making Earth warmer
This handout photo provided by The National Oceanic and Atmospheric Administration (NOAA) shows Arctic sea ice in 2013. 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. (AP Photo/NOAA)

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, 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 , 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 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 (90,650 sq. kilometers)—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 scientist Waleed Abdalati, who was not part of the research, called the work important in understanding how much is getting trapped on Earth.


Explore further

Arctic ice shrinks to all-time low; half 1980 size (Update)

More information: "Observational determination of albedo decrease caused by vanishing Arctic sea ice," by Kristina Pistone, Ian Eisenman, and Veerabhadran Ramanathan. PNAS, www.pnas.org/cgi/doi/10.1073/pnas.1318201111

© 2014 The Associated Press. All rights reserved.

Citation: Study: Arctic getting darker, making Earth warmer (2014, February 17) retrieved 15 June 2019 from https://phys.org/news/2014-02-arctic-darker-earth-warmer.html
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Feb 17, 2014
We messed up the environment. Forget global warming, prepare for global fisting.

Feb 18, 2014
Yet another example, of where we are underestimating rather than overestimating the effects of AGW. The Arctic being particularly vulnerable to it via ice melt/albedo decreases.

Feb 24, 2014
We messed up the environment. ...

What do you mean "we", stupid. G'ment is the dirtiest industry on the planet.

Feb 24, 2014
Yet another example, of where we are underestimating rather than overestimating the effects of AGW. The Arctic being particularly vulnerable to it via ice melt/albedo decreases.


Never in history has raising taxes changed the weather. And since government is the dirtiest industry on the planet, increasing tax revenues to government would only produce the same: more dirt and more, not less AGW.

Feb 24, 2014
We messed up the environment. ...

What do you mean "we", stupid. G'ment is the dirtiest industry on the planet.
You ever heard of "We the People" stupid? And your stupid comment about taxes is also an example of stupid people taking a stupid position on a subject they are too stupid to understand.

Feb 24, 2014
What do you mean "we", stupid

@FastEddy
Homo Sapiens, people, etc.
see Maggnus explanation above.
G'ment is the dirtiest industry on the planet

personal conjecture and irrelevant
Never in history has raising taxes changed the weather

personal conjecture and irrelevant
since government is the dirtiest industry on the planet, increasing tax revenues to government would only produce the same: more dirt and more, not less AGW

personal conjecture without evidence as well as irrelevant
please provide links/studies/reports/empirical data for support and relevance

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