Byline: Emily Stone

Eleven years ago, Ann Alexander was kayaking in Alaska in a bay that didn't exist 40 years before. Rapidly retreating glaciers opened up the waters below, leaving behind a sculpture garden of icebergs lit by the golden-red glow of the midnight sun.

"I'm in one of the most spectacular places I've ever seen in my life,'' Ms. Alexander remembers thinking. But it also frightened her to see such stark signs of global warming.

That love of nature and concern over humans' impact on it are at the core of her work as an environmental lawyer in the Chicago office of the Natural Resources Defense Council, an environmental advocacy group with 350 lawyers, ...