Is Warming Causing Alaska Meltdown?

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This is not the case for polar glaciers like those found in Antarctica and Greenland. Polar or "cold" glaciers, which typically have temperatures significantly below freezing, show only minor responses to changing climate. More than 96 percent of the glacier ice on Earth is polar.

"Look at it this way. Around 18,000 years ago, glaciers extended all the way down to Illinois. By 12,000 years ago it had retreated 40 miles (65 kilometers), and by 7,000 years ago the continental ice masses disappear. Over a period of 4,000 to 5,000 years there's no ice left, all without any human intervention at all. We've had similar glacial advances and retreats at least four times in the last 2 million years.

"Temperate glaciers are the bellwether of warming; it doesn't take much of a change in the regime to change the balance. Whether human activity has accelerated the pace of glacial retreat we can only speculate. The glaciers were already going into retreat."

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