As Secretary of State under President Ronald Reagan, George Shultz helped negotiate the most successful global environmental treaty to date: the Montreal Protocol, which phased out the use of chlorofluorocarbons and other ozone-depleting chemicals. Those chemicals also act as potent greenhouse gases, so the agreement also makes him the negotiator of one of the most effective global climate treaties ever, despite being part of an administration that famously removed solar technology from the White House roof.

Few modern Republican politicians favor such environmental effort, or even believe climate change is happening or that humanity could be primarily responsible for it. In addition, the Republican-controlled U.S. House of Representatives is currently suggesting that the federal budget almost eliminate support for the Advanced Research Projects Agency for Energy and other clean energy efforts from the Department of Energy. Still, Shultz continues to work for what he sees as improvements to U.S. national, economic and environmental security by addressing the growing threat of global warming through his role as chair of the energy policy task force of the Hoover Institution at Stanford University.

Scientific American sat down with the 92-year-old Schulz to discuss what can be done to combat climate change in the present political environment. The interview was held at his home in the hills above Stanford, which boast solar panels and his electric vehicle—a Nissan LEAF—in the garage.

Editor's Note: David Biello is the host of a forthcoming series on PBS stations, a sequel to the award-winning Beyond the Light Switch. The series, produced by Detroit Public Television, will continue to explore how transformation is coming to how we use and produce electricity, impacting the economy, the environment and national security.

[An edited transcript follows.]

Your long career in government was often focused on protecting the U.S. How will climate change affect national security?

I think in the energy area, we have to be constantly aware of three big objectives. Number one: we have to think of energy as a strategic commodity that is very important to our national security. Number two: we have to recognize that energy is the engine of the economy, so we want inexpensive, reliable, consistent energy. And number three: we have to recognize that energy produces pollutants as it burns, so it affects our environment. It affects the air we breathe; it affects the climate we create. So we have these three issues to keep in mind all the time, and you can't just do one or the other, but you've got to work on them all at the same time.

How is the military addressing the energy and climate challenge?

We see supply trucks blown up as they're going into Afghanistan, and, of course, that means first of all that people are losing their lives. Second of all, the net costs by the time you get the fuel there are astronomical. So you want to create more fuel where it isn't, so you don't have that transportation problem. The answer is to figure out how to create more energy where you use it.

The Navy is creating hybrid boats where, as long as you can go slow enough, you can propel your ship by electric power, which is more economical to create on the ship than liquid fuels, meaning you don't have to go into port and refuel as much.

They look on this as something that improves their war-fighting capability. When a ship is in port refueling, it's not able to fight a war. The longer you can keep it on station, the more useful it is in its basic role. So all these things fit together.

You've had a distinguished career in government. Have we missed chances along the way to improve our national, economic and environmental security?

I remember distinctly 1973. I was Secretary of the Treasury, and in that year’s Arab-Israeli war, we resupplied the Israelis. The British and French denied us access to their airports, so oil flowed to them and it was cut off from us: The Arab oil embargo.

At that time, a lot of our electric power was produced by oil, so it had a huge impact here on our economy. At Christmas-time, lights were out and so on. It was a cultural impact as well as a national security impact.

There was no Energy Department then, so the Treasury Department inherited the problem. I was, in effect, the de facto Secretary of Energy. And people would come in to me and say: "Look, here are these ideas for alternatives." They sounded reasonable, so they got some support.

Then the crisis passed. The price [of oil] goes down and everything stops. We've been through that cycle, and this time, in my opinion, we just have to see to it that that doesn’t happen again. We have to keep the funding going for energy [research and development] because that's where the long-run future is. That's where people are going to create things that we probably don't even know about now that are going to make us more secure energy, more economically useful energy and energy that is more benign as far as our environment is concerned.

So the pull back in energy R&D funding was a mistake?

Absolutely. They were bad mistakes.

I feel like every president since I've been alive has talked about energy independence. Is that the right goal?

The ability to generate the energy we use is of vital importance, just in security terms. And we are on the cusp of being able to do that because of fracking technology, which incidentally is a classic outcome of government [research and development] combined with entrepreneurial people.

So already the natural gas picture in this country has been revolutionized. Already, our emissions are coming down because gas is substituting for coal.

When you look back at your own career, are there any achievements or episodes that give you hope that this country might address climate change in a more coherent way?

We had a version of the climate change issue in a little different way when I was Secretary of State in the 1980s. There were a lot of scientists who thought that the ozone layer was depleting. There were some who doubted it. They all agreed that, if it happened, it would be a catastrophe.

I had two private meetings a week with President Reagan, and we talked about it. We decided that we should take out an insurance policy. Rather than go and confront the people who were doubting it and have a big argument with them, we'd say to them: Look, there must be, in the back of your mind, at least a little doubt. You might be wrong, so let's all get together on an insurance policy.

It wound up as a treaty called the Montreal Protocol.

In retrospect, it's clear that the scientists who were worried were right, and the Montreal Protocol came on in the nick of time. So, on a lot of these issues, time is not on your side because [environmental problems] can get, if not beyond repair, increasingly hard to repair.

I also worry about discontinuities.

You can point to a number of things that might produce a discontinuity, where, in other words, suddenly things get much warmer quickly, and you scramble around to do something. We know that carbon stays in the atmosphere. It doesn't disappear. You know, a new ocean is being created for the first time since the Ice Age [in the Arctic with the meltdown of sea ice]. How could that happen? It's getting warmer.

Is electrification of cars and other kinds of transportation the answer for taking the carbon dioxide out of that side of our economy?

I don't know that it's the answer, but it is one of the answers. You have to ask: How are you producing the electricity? So if you've got big coal plants producing electricity, you're not getting anywhere. If they're natural gas, you're much better off, but if it's solar electricity, you're even better off.

We've had these renewable energy efforts in the past, like after the first oil crisis in the 1970s, but they weren't sustained. Are things different now?

Solar panels right now are almost competitive with the grid, and if you talk to the scientists working on them they are full of ideas for what they call improving efficiency. Getting more power out of a given sunbeam. But half the costs are installation costs, pick-and-shovel work. So I said to them: Why don't you start thinking about how you build something that's easier to install? If we could build something that's half the cost of installation, bang—the costs are way down.

I think it's essential in this country, and I encourage it around the world, to maintain the funding for the [research and development] effort that's going on right now. There's a greater mass of it than ever before. The amount of money from the federal government is nothing compared with the total budget, and as I've seen here at Stanford, the federal commitment and the federal money is more than matched by private money.

You've got solar panels on your home. Why did you do that?

I figure I've got to walk the talk. They've been on [the roof] for about six years. I have a little chart that has my electricity bill before and after, and if I take the amount of money I've now saved, I've paid for the panels plus the opportunity cost of that money. I also have an electric car. I drive it around campus and around town. I don't have any range anxiety.

You have no range anxiety whatsoever with your electric car?

Well, I don't take it for long distances. Most of the driving everybody does is around where they live. And I have a charging device in my garage so I figure I'm driving on sunshine, and it's free. It doesn't cost me anything, so I kind of like it.

What drives you to keep working on these problems?

I'm in my 90s and I live here on the Stanford University campus. It's dreamy. It's so nice. However, I have four great-grandchildren.

It's fun to have little babies around again, but you look at these little kids and they're so full of vitality and curiosity and so much fun in them. You can't help but ask yourself: What kind of a world are they going to inherit, and what can I dredge out of my experience that might be put into place to help make it a little better?