Michael Oppenheimer

You are one of the authors of a major study on the effects of global warming. What were its main conclusions?

The major conclusion is that it is unequivocal that the Earth is warming. These changes are attributable to the human-made buildup of greenhouse gases, primarily carbon dioxide from burning the fossil fuels. The climate is changing pervasively and humans are responsible. Unless these changes are reined in soon, there will be a world-shaking climate change by the end of this century.

You were trained as an astronomer. When did you switch over to being a climatologist?

Starting in the late 1960s, I became interested in the environment and air pollution. My professional knowledge about the atmosphere converged so that during late 1970s I became intensely interested in the problem of acid rain. That led me to abandon a thriving academic career and work for the Environmental Defense Fund as its chief scientist.

You've been writing about this stuff since 1984. Why did it take most of us so long to pay closer attention?

When I started thinking about global warming, it was an arcane problem that only a handful of scientists focused on—very few people in the general population had any idea about it and governments were basically clueless. And gradually it's penetrated into everyone's consciousness until right now when it is really a forefront issue—as important as national security.

These days there's a lot of trendiness involved in going green. What do you make of that?

I don't think there's any problem with trendiness, if it means looking at what other people are doing and following their example. If it's a good example, trendiness is a good thing.

How big of a change in social and individual behavior will make a real impact?

It needs to be solved both from the bottom up and the top down. People have to think about the ways they contribute to the problem, but it's such a big issue that to get that across-the-board action to reduce our dependence on fossil fuels, governments will have to implement mandatory restrictions on emissions. You've got to look at your own life: What kind of car are you driving? What kind of light bulbs do you use? What kinds of appliances do you have in your home?

What are three things that you recommend to people who would like to do their part but don't know where to begin?

When you buy a car, make sure it's the one that gets the highest possible fuel economy for the type you want. Replace light bulbs with compact fluorescent bulbs because they last ten times as long and use a quarter as much energy as standard incandescent bulbs. And maybe most important, bother your politicians — call them up, email them, let them know this is an issue on which you are expecting their leadership support.

What does "green" mean to you?

Green means the realization that everything we do ultimately affects the fate of the planet and everybody that lives on it. It means passing a planet onto my children and grandchildren that I would want to live on.

Do you have any eco-sins — areas where you'd like to be green but you aren't?

My eco-sin is I eat too much takeout food. It comes in plastic containers that can't be recycled.

You live in New York and teach at Princeton. What's your usual mode of transport?

I take public transportation — I take NJ Transit and when I get to Princeton, I walk to get to my office. That's pretty green!

Al Gore's An Inconvenient Truth: Friend or foe?

I think he's a hero, dedicating his life for the last few years to putting this issue on the map. It has had a tremendous effect in getting attention for the issue that would have been hard to get in other ways. The climate is starting to change in ways that we can see—people are aware of heat waves, they're aware of the intensification of hurricanes, they're aware of the sea level rise. Now we are finally at a threshold where the issue is going to be dealt with in a serious way.

What recent green habits have you adopted?

I walk when I can — not only because it's good for the planet, but because it's good for me.