for National Geographic News
For the second year in a row a large amount of Arctic sea ice did not refreeze during the winter as it normally does, a team of scientists reports.
This trend may indicate an overall shrinking of Arctic ice cover due to rapid global climate change.
Mark Serreze is a senior research scientist at the National Snow and Ice Data Center based at the University of Colorado, Boulder, who monitors Arctic sea ice.
"Some calculations say that by 2070 we will have no sea ice left," he said.
"It's always dangerous to make predictions, but we are right on schedule" for this to occur.
The ice that floats on top of the Arctic Ocean typically melts a bit in the spring and builds up again in the winter.
Animals such as polar bears, seals, and walruses make their homes on the ice, and people living in the region rely on the ice pack for fishing and travel. (Read how ice melt may be killing polar bears.)
But this year and last year the winters were too warm for the ice to re-form normally, the scientists say.
"It's getting so warm in the Arctic now that the ice is not growing back in winter the way it used to," Serreze said.
The Arctic region made the news last September when the same team of researchers reported that a very warm winter followed by a warm summer had resulted in less ice on the ocean than had ever been recorded.
If this spring and summer are also warmer than average, "come this September we could be in really bad shape," Serreze said.
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