FORTUNE — When David Hawkins and his wife were newly married, they spent a summer on an island off the coast of Nova Scotia. Hawkins was taking a leave of absence from Columbia University’s law school and considering whether he really wanted to be a lawyer. The trip to the island made his decision for him. The experience of watching the seasons change and enjoying beauty of nature were an eye-opener, and Hawkins quickly realized that he wanted to go back to law school to work on environmental protection.
He wound up working for the Natural Resources Defense Council — with a brief stint at the EPA under the Carter administration — and has spent the last few decades trying to change public policy on global warming. Hawkins, 70, lives in Connecticut and commutes to both New York City and Washington, D.C. He rides his bike to the train station most days and prefers to spend his evenings reading at home or attending choir rehearsals.
He spoke with Fortune.
1. What alternative energy projects are you most excited about?
Wind power and new solar power technologies are extremely exciting, but I also tend to specialize in what’s known as “carbon capture,” a technology for capturing carbon dioxide from fossil fuels and power plants. It’s not alternative energy in the traditional sense. It prevents carbon from getting into the air. It’s captured and compressed, and then it’s put into a pipe and buried in geologic formations.
2. What green business or person do you admire most? Why?
It’s somebody who unfortunately is no longer with us, a guy named Ray Anderson, who formed Interface carpet. He made, as the name would suggest, carpets. He introduced a completely green manufacturing process. He made these carpet materials so that they were completely recyclable. He organized a system of buying back carpet and reusing it. We’re constantly going back to the well to produce more materials when we could be intersecting with those materials after they’ve been used. Instead of sending them to the dump or the incinerator, we can send them back to production facilities, and that would greatly reduce large amount of material that we use. Ray recognized that.
3. What is the best advice you ever received?
It was from a law school professor, and the advice was, “When you are arguing a case, tell an interesting story. Because the judges and their clerks are human beings, and human beings like hearing stories.” So the idea is you present your case and argument with a story line, and people essentially gravitate to story lines and they imagine how they like to have those stories end. I almost always keep that in mind when I’m talking to an audience or a member of Congress. When I say “tell a story,” I don’t mean lie, but present the information in the form of a narrative that has an arc and a flow.
4. What would you do if you weren’t working at your current job?
I would like to run a bookstore. I love books.
5. What books are you currently reading?
A fiction book called The Luminaries. It was a recent winner of the [Man] Booker prize. I also read a book on the 1857 history of Greenwich, Conn. And I just started the diary of a woman who spent a year as an intern for Frank Lloyd Wright in the 1930s. I like fiction, I like classics, and I like modern literature as well. I’m pretty eclectic.
6. What is one goal that you would like to accomplish during your lifetime?
I would like to get the U.S. to treat climate change as a top priority issue. My top priority and the organization’s top priority is to get the EPA to adopt carbon pollution standards for coal-fired power plants. That would be a regulation under the Clean Air Act.
7. What was your biggest missed opportunity?
Not talking more to my mother and father. It was not something that I realized I would value as much as I now realize it.
8. What do you do to live a balanced life?
I spend a lot of time singing. I’m in two choruses, so I have a couple of rehearsals every week. One is a chorus in Connecticut, and one is a Russian chorus in Manhattan. I don’t speak Russian, but I know how to read and speak transliterated Russian. Reading is another huge resource for me — to not just be thinking about my work tasks.
9. What was your first job?
My first job that wasn’t a summer job was teaching math. When I took time off from law school, I taught math at the Dalton school, which is a private school in New York City. I loved it. I taught several different grade levels. I tried to make it fun because math is really about puzzles. I tried to introduce as many puzzles, interesting questions, issues of logic and communication as I could while teaching the basics of arithmetic.
10. What is one unique or quirky habit that you have?
My singing is certainly not unique, but I like to yodel. Whenever I’m in a space that has really great acoustics, I can usually not resist yodeling.
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