In 2011, annual snow cover extent over Northern Hemisphere continents (including the Greenland ice sheet) averaged 24.7 million square kilometers, which is 0.3 million square kilometers less than the long-term average.

Kristin Laidre, a marine mammal biologist, has taken more than thirty trips to the Arctic, many of them to study the mysterious narwhal. Although the narwhal has appeared in stories throughout history, scientists are just beginning to understand this quirky creature with a fierce survival instinct. But in recent years, a series of unusual events led Laidre to wonder if narwhals are being caught off guard by changes in their unforgiving environment…

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