All Photographs © Paul Nicklen / National Geographic

A young polar bear leaps between ice floes. Barents Sea, Svalbard, Norway. These photographs are from Paul Nicklen’s recently released book, Polar Obsession (National Geographic Focal Point, $50), the culmination of 15 years of work photographing wildlife in the arctic and Antarctica. The book celebrates the arctic and Antarctic ecosystems and discusses the urgent need to halt global warming, which threatens their existence. For more from Nicklen on Polar Obsession, see our recent interview with the photographer.

A kittiwake soars in front of a large iceberg. Svalbard, Norway.

In the Arctic spring, meltwater channels drain toward and down a seal hole, returning to the sea.

Narwhals dive deep under the ice to feed on Arctic cod, then return to the surface to breathe and raise their tusks high in the air. Lancaster Sound, Nunavut,
Canada.

A gentoo penguin chick peeks, checking for patrolling leopard seals before tempting fate. Port Lockroy, Antarctic Peninsula.

A leopard seal feeds Paul Nicklen a penguin. Antarctic Peninsula.

A large bull walrus returns to the shores of Prins Karl Forland after diving and feeding on clams. Svalbard, Norway.

Mother bear and two-year-old cub drift on glacier ice. Hudson Strait, Nunavut, Canada.

Looking towards an uncertain future, a huge male bear triggers a camera trap, taking his own picture. Leifdefjorden, Spitsbergen, Norway.

For more from Nicklen on Polar Obsession, see our recent interview with the photographer.