Penguins Chronicle Climate Change

Scientists have figured out a new way to measure climate change's effect on the Antarctic ice shelf by studying the region's penguins.

Adélie penguins are the smallest and most widely distributed penguins in Antarctica. They nest in ice-free areas along the coast and mark the edge of the sea with their remains—bone, tissue, feathers, feces and eggshells—almost perfectly preserved.

By dating the remains, Steven D. Emslie of the University of North Carolina Wilmington has charted the ancient penguin colonies' population shifts over the last 45,000 years. This record was combined with climate change data to create a new and reliable method of dating ice movement.

The study, published in the January 2007 edition of Geology and announced today, describes how Emslie measured the advance and retreat of the Ross Ice Shelf and determined that the ice shelf advanced northward in the Ross Sea until about 13,000 years ago, when it began retreating at the end of the last.

The Antarctic ice sheet plays a critical role in global climate control by reflecting sunlight into space and helping to cool Earth's air and oceans.

—LiveScience Staff

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