Science & Environment

Refrigerators, foam buoys and even ketchup bottles are piling up on Alaska's beaches. Almost two years after the devastating Japanese tsunami, its debris and rubbish are fouling the coastlines of many states — especially in Alaska.

At the state's Montague Island beach, the nearly 80 miles of rugged wilderness looks pristine from a helicopter a few thousand feet up. But when you descend, globs of foam come into view.

The U.S. government is investing millions of dollars in what it considers a promising new industry for American manufacturing: nuclear reactors. The plan is to build hundreds of mini-reactors, dot them around the U.S. and export them overseas.

The last few years have been especially tough in South Florida for wading birds such as egrets, herons, ibises and wood storks that feed and nest in the region's wetlands.

The problem is there are fewer wetlands, and the last few years have been dry, reducing water levels in critical areas.

In 2008, reports of polar bears' inevitable march toward extinction gripped headlines. Stories of thinning Arctic ice and even polar bear cannibalism combined to make these predators into a powerful symbol in the debate about climate change.

The headlines caught Zac Unger's attention, and he decided to write a book about the bears.