Vast expanses of Arctic ice melt in summer heat

TUKTOYAKTUK, Northwest Territories

“Forty years ago, it was 40 miles (64 kilometers) out,” said Gruben, 89, patriarch of a local contracting business.

Global average temperatures rose 1 degree Fahrenheit (0.6 degree Celsius) in the past century, but Arctic temperatures rose twice as much or even faster, almost certainly in good part because of manmade greenhouse gases, researchers say.