Long Summers Force Polar Bears to Hunt on Thin Ice

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Long Summers Force Polar Bears to Hunt on Thin Ice

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UK: October 31, 2003

 

 

LONDON - Longer Arctic summers and thinning sea ice are threatening the

habitats of polar bears and the livelihood of native people, scientists said

Wednesday.

 

 

 

Arctic ice has lost as much as 40 percent of its thickness in the past 50

years.

 

But researchers, who measured it from space for the first time, said it

varies more widely than previously thought and is mainly because of summer

melting.

 

" We found a direct link between lengthening summers and thinning ice, " said

Seymour Laxon of University College London.

 

The thinning sea ice will not cause sea levels to rise but it could have a

knock-on effect for the climate, Arctic ecosystems and wildlife.

 

" There is a lot of concern about the effect on the people in the high

Arctic. They rely on the ice to do their hunting and fishing and each year

the ice season is getting shorter and shorter, " Laxon said.

 

" They are very concerned about how that is going to change their way of

life, " he added in an interview.

 

The thinning ice could also increase the impact of global warming in the

northern hemisphere and may influence the operation of the Gulf Stream,

according to Laxon.

 

Instead of using computer models, scientists developed a technique to

measure the thickness of the ice covering the circumference of the Arctic

Ocean with radar data from a European Space Agency satellite and images from

an American satellite.

 

Their research is reported in the science journal Nature.

 

The satellite bounces radar off the ice surface and by measuring the height

of the ice protruding above the water surface, the scientists can measure

how thick the ice is.

 

" When we compared the data from the two satellites we were astonished by the

similarity between the changes in the ice thickness and the length of the

summer melt season, " Laxon said.

 

" This result suggests that if this continues, further melting will occur,

leading to the eventual disappearance of the ice during summer, " he added.

 

The satellite technique gives scientists an idea of what has been happening

to the ice over the last decade and allows them to cover greater areas than

other methods.

 

 

 

Story by Patricia Reaney

 

 

 

REUTERS NEWS SERVICE