A discussion with the NASA and Columbia University climatologist.

James Hansen: Well, I'm Jim Hansen. I'm a climatologist. I work at NASA and also at Columbia University.

Question: What is a basic definition of climate change?

James Hansen: Yeah. Well, human-made global warming is caused by changes in the atmosphere which are due to burning fossil fuels, primarily. As we burn oil, gas and coal, this releases carbon dioxide to the atmosphere. And carbon dioxide absorbs heat radiation from the earth, and that traps the heat radiation and makes the planet a bit warmer. So we notice that the world has warmed up about one and one-half degrees Fahrenheit in the last century, with most of that warming in the last 30 years.

Question: What is the latest conclusion on CO2 emissions?

James Hansen: Yeah. Well, there's now 387 parts per million of CO2 in the atmosphere. A hundred and fifty years ago it was 280, so it's increased by 107 ppm. What we thought a few years ago was that it would probably be safe to let CO2 go as high as 450 parts per million. The reason we thought that was that we know that there were previous periods in the earth's history called interglacial periods -- we're now in a warm interglacial period, which we have been in for about 12,000 -- but there were prior periods when the earth was warmer than it is now, and the planet was still pretty much the way it is now. And we thought that -- it was then about a degree or so Celsius, which is about two degrees Fahrenheit, warmer than it is now -- and we thought that might be okay to be that warm. And 450 parts per million would probably take us to that sort of a climate.

But what we now realize is that during those prior warm periods, sea level was about six or seven meters higher than it is now. And also we see what's happening with the current 387 parts per million. That's already enough that the arctic sea ice is melting, mountain glaciers all around the world are melting, which is going to affect the fresh water supply for billions of people. The climate zones are shifting, so the southwest United States and Mediterranean region are becoming hotter and drier; likewise Australia. So you see increased forest fires and reduced water supplies in those regions. Coral reefs are already under stress; many of them are going to be lost if we continue with increasing greenhouse gases. So we realize already that 387 is actually too large. About 350 parts per million is a more realistic target, and that means we're going to have to phase out use of coal over the next couple of decades if we want to be able to get back to 350 parts per million.

Question: Are you critical of the use of fossil fuels?

James Hansen: We simply -- if we look at the fossil fuels and we see how much carbon there is in oil, gas and coal -- and by far the largest is coal -- and we know that we're going to use the oil and the gas; they're very convenient fuels. The big pools are owned by Russia and Saudi Arabia. They're certainly going to sell that gas and oil. If we want to be able to get back to 350 parts per million, it's this huge coal reserves that we're going to have to leave in the ground. Or we could burn the coal and capture the CO2 and put it back in the ground, but that's very difficult. We're going to have to move beyond fossil fuels sometime within the next century anyway, so why not do it now and preserve a climate that will allow our children and grandchildren to have the same sort of planet that we enjoyed, and with all of the species that are still on the planet? [00:05:09.00]

Question: How can we wean ourselves off of coal?

James Hansen: Yeah. There's one huge step, and that is putting a price on carbon emissions. It's really that simple. If we put a gradually increasing price on carbon emissions by putting a tax at the source, at the mine or at the port of entry where the fossil fuel is imported to our country, then as that price rises, then energy efficiency, renewable energies, nuclear power -- the other forms of carbon-free energy -- can compete more effectively against the fossil fuels. But in order for the public to accept this, and in order for the public to have the money to invest in a new vehicle and insulating their home, we have to give all of this money to the public.

If we put a price on carbon equivalent to $1 a gallon of gasoline, that would generate $670 billion in one year in the United States. If you return this to the public, to legal residents of the United States, that would be $3,000 per adult legal resident. And if you give half a share to children, up to two per family, that's $9,000 per family with two or more children. So that would give the public the money to make the changes in their lifestyle that are needed to move us off of fossil fuels into a cleaner future, because right now the fossil fuels are the main source of air pollution, which is killing in the United States about 40,000 to 50,000 people per year; worldwide a much larger number than that, because the pollution is much worse in China and India than it is in the United States. So we have many reasons to want to move beyond the fossil fuel era.

Question: What is the likelihood of this actually happening?

James Hansen: It could happen very easily if our governments would move in that direction. And by the way, this has happened; it is happening now in British Columbia, Canada. They have imposed a carbon tax with the money returned to the public. They do it via a decrease in payroll taxes. I would rather see a dividend because half the people are not on a payroll; either they're retired or they're out of work. But you could use, say, half of it for a payroll tax deduction and half of it for a dividend. 

Question: How would nuclear power work on a large scale?

James Hansen: Well, nuclear power -- the kind of nuclear power we have now is called second-generation nuclear power. It's comparable in cost to coal. Once you have the nuclear power plant, then the fuel is very inexpensive, so nuclear power is quite inexpensive. But it's difficult in the United States to get a nuclear power plant built, and it takes so many years that it drives the cost up. So now in England they've realized that they will need to have nuclear power in the future, so they've put a limit -- once a government commission decides on where the power plants will be built, the public will have one year to object to this and possibly get some changes. But they can't drag it out six or seven years, the way it happens in the United States, because that drives up the price tremendously.

And there's also the possibility for fourth-generation nuclear power. That's a technology which allows you to burn all of the nuclear fuel. Presently, nuclear power plants burn less than 1 percent of the energy in the nuclear fuel. Fourth-generation nuclear power allows the neutrons to move faster, so it can burn all of the fuel. Furthermore, it can burn nuclear waste, so it can solve the nuclear waste problem. And the United States is still the technology leader in fourth-generation nuclear power. In 1994, Argonne National Laboratory, now called Idaho National Laboratory, was ready to build a fourth-generation nuclear power plant, but the Clinton-Gore administration canceled that research because of the antinuclear sentiments in the Democratic Party. Well, we still have the best expertise in that technology, and we should develop it because it's something we could also sell to China and India, because they're going to need nuclear power. They are not going to be able to get all of their energy from the sun and from the wind.

Question: What is the most effective approach to alternative energy?

James Hansen: Well, the most effective one is energy efficiency. We waste a lot of our energy. We can get vehicles that get more miles per gallon. There are many ways to improve energy efficiency. In fact, some states are twice as efficient as other states, just because -- fossil fuels were so cheap we just didn't pay attention to how effectively we were using them. But in addition, there are renewable energies: solar energy, wind energy. And I think that nuclear power has to be part of the solution, because at this time it's the only alternative to coal for base-load electrical power. And we do now have the technology for much safer and more efficient nuclear power, as compared to the old versions that were used in the past several decades.

Question: Will the cap-and-trade proposal curb emissions?

James Hansen: Yeah. You know, Obama is still perhaps our best hope, but he's going to have to study this problem and understand it. Presently, his approach is to let Congress debate it and make their horse trading, and end up with some sort of compromises with the polluters. And then we end up with this cap-and-trade and offsets, and a completely ineffective system. But this situation, in which we can see what we are doing to future climate and what the implications will be for young people -- we're in danger of sending them into a situation where dynamical system will be out of their control. But this -- the intergenerational injustice of that is -- this problem is analogous to that faced by Abraham Lincoln with slavery, or Winston Churchill with Nazism. It's not a problem where you can compromise. Lincoln couldn't say, well, let's reduce the slaves by 50 percent. You can't compromise on this; we have to phase out the carbon dioxide emission over the next several decades. And frankly, that means phasing out coal emissions. And this cap-and-trade system doesn’t do it at all.

Question: Why do you feel many politicians support the bill?

James Hansen: Well, they are -- they're taking the easy way out. They're allowing the polluters to write the bill. The Waxman-Markey bill in the House is 2,000 pages long. Do you think that Representative Waxman wrote this? No, this is written by the polluters; and even by environmentalists -- there are good points in those bills also. It's filled with the polluters' point of view and some environmental things to increase solar power, for example. But that's not going to solve the problem. It's just like the old Kyoto Protocol approach. They have to face the fundamental issue: as long as fossil fuels are the cheapest energy, then they are going to be burned, and their use will continue to increase. You have to face it. That's what the lawmakers are not facing, and that's what President Obama has got to understand. So the only way you can address that is by putting a rising price on the carbon emissions. Then the alternatives -- the renewable energies, energy efficiency, nuclear power, anything that doesn't produce carbon -- will compete more effectively, and those which are most effective will begin to win economically.

Question: Do you feel anybody in Washington sees this?

James Hansen: Yes, there are people in Washington who get it. There is one bill that was introduce in the House which had a gradually increasing carbon price. The Democratic Party -- it was introduced by a Democrat, and I'm sorry I can't think of his name of the moment -- but it was conveniently ignored by the Democratic Party. We've got to have an open discussion of this. I think the public is not excited about this issue the way they were about health care. But we need to have that kind of an open discussion so that we see what the alternatives are, because this approach that is being pushed by the Democratic Party is a disaster.

Question: Can you describe your recent activism efforts?

James Hansen: Well, activism is going to be necessary, it seems. We have to draw attention to the intergenerational injustice in climate change. You know, I went to Massachusetts because I recognized that they're a very progressive state, and I had hoped that -- you know, we have to find one state that will take an approach that works. And that means a carbon price, with the money, 100 percent of the money, returned to the public. There's a province in Canada that 's doing that, but people in the United States don't pay that much attention to what's happening in British Columbia, Canada. If we had one state that would pass a law with carbon price and 100 percent dividend to the public, then I think people would wake up, and they would say, hey, this works, and it's to the advantage of the public, not to the polluters.

 Question: Did you make any progress?

James Hansen: But the problem was that Massachusetts had already been listening, and they had begun to take action a year ago. What action? Cap-and-trade. So getting them to change direction at this point seems very difficult. I'm going to write something soon, trying to find one state -- one out of 50 states -- that is in a position and has leaders that can understand what is needed and may be willing to serve as an example for the other 49 states.

Question: What states do you feel are progressive enough to embrace this change?

James Hansen: Well, there are states that are progressive and have been trying quite hard. California's a good example, but again, I think they have already taken initial steps in a different direction. So I haven't looked carefully enough to say what is the best candidate state.

James Hansen: Well, I have children and grandchildren, and I've decided that I am going to try to make clear what the implications are. And I certainly have every right to do that. And I think that scientific colleagues are now much more willing to go along with that. If you go back a few decades, scientists tended not to like it if other scientists spoke up publicly. But the scientific community recognizes this is an issue where we have to educate the public.

Question: What will life be like if carbon emissions continue to grow?

James Hansen: Well, if we allow emissions to continue at a high rate, in this century we're going to see ice sheets begin to disintegrate. And one of the things I write about in my book is the effect that will have on storms, because as Greenland begins to release more fresh water, cold fresh water, and Antarctica does, what it does is cool the North Atlantic Ocean and the southern ocean, and that increases the temperature gradient between low latitudes and middle and high latitudes. And that will increase the strength of storms that are driven by horizontal temperature gradients. So our children can look forward to increasing storms. And with a rising sea level that is going to lead potentially to a very chaotic situation, because once you have hundreds of cities in the situation analogous to what happened in New Orleans, then we've got an economic situation that's just out of control globally.

In the long run, if that really happened, as I point out in the book, over centuries, we could actually get a runaway greenhouse effect, and then that's it for all the species on this planet. And as I try to point out, there's no practical way to escape from this planet; we can't even transfer one species to another planet. I discuss the monarch butterfly and just how complex it is. And for us to hope that we could transplant life from our planet to another planet is really unrealistic. [00:21:59.17]

Question: What is the runaway greenhouse effect?

James Hansen: A runaway greenhouse effect means once the planet gets warmer and warmer, then the oceans begin to evaporate. And water vapor is a very strong greenhouse gas, even more powerful than carbon dioxide. So you can get to a situation where it just -- the oceans will begin to boil, and the planet becomes so hot that the ocean ends up in the atmosphere. And that happened to Venus. That's why Venus no longer has carbon in its surface. Its atmosphere is made up basically of carbon dioxide because it had a runaway greenhouse effect. Now the earth, it can go unstable either toward a cold climate or toward a hot climate. And the earth has had a runaway snowball earth situation. This happened most recently about 700 million years ago. The earth froze all the way to the equator.

So these runaway situations can occur. We've never had a runaway greenhouse effect, because if we did, that would have been the end. Once -- that's a permanent situation. In the case of a snowball earth, when the earth becomes ice-covered, then the planet can escape from that situation because volcanoes continue to go off, but the weathering process is greatly reduced. So volcanoes put carbon dioxide into the atmosphere, and it builds up more and more until there's enough to melt the ice. But we can't push the planet off of the runaway greenhouse end. That's the end for everybody if we do that.

Question: How long would this take to occur if we stay on this path?

James Hansen: Well, you would have to -- first of all, you'd have to melt the ice sheets, and that takes a while. The Antarctic ice sheet is a couple miles thick. But with continued rapid increase in greenhouse gases, that -- you could melt the ice sheets in less than a century. And then things start to get hotter and hotter. So over a period of several centuries it would be conceivable to have a runaway greenhouse. That would also require bringing into play what we call the methane clathrates or methane hydrates. We already observe in the tundra region in Canada and Siberia that as the tundra is melting, methane, frozen methane, begins to be released. And methane is another powerful greenhouse gas. And there have been times in the earth's history when the methane hydrates on the continental shelves melted and went into the atmosphere and caused global warming of six to nine degrees Celsius, which is 10 to 18 degrees Fahrenheit. So if you add that on to the carbon dioxide warming and the water vapor warming, you could begin to push the planet into a very different state.

Question: How can businesses help fight climate change?

James Hansen: Well, businesses -- you know, Congress does listen to businesses. And they need to -- you know, our -- I call them the captains of industry -- they're the ones who are -- their support is needed to solve this problem. And they need to put some pressure on Congress to do the things that are needed rather than asking for special favors. Business leaders would actually like Congress to set a schedule for changes that are needed, and they would actually favor -- most of them, I think, would favor a gradually increasing, well established carbon price rather than this cap-and-trade which can oscillate, and you don't know how the impacts will be on your business. But if they knew what the increasing price on carbon was going to be, then they can make the changes to their business that are needed in order for them to continue to make money or even make more money; begin to invest in those things that are carbon-free.

Question: Are any businesses doing particularly well in this?

James Hansen: Well, there are businesses that are beginning to emphasize energy efficiency. We need -- in order for that to really work, there does need to be a carbon price. And there are some industries that are beginning to tell Congress it makes more sense to have a carbon tax and dividend than it does to have cap-and-trade.

Question: What are these industries?

James Hansen: Well, you know, one of them, which makes people nervous, is -- the CEO of Exxon Mobil said carbon tax is a good approach. Well, that makes people nervous, because Exxon Mobil has been one of the biggest producers of carbon dioxide. But in fact, that is what's needed. So we're willing to take support from wherever it comes.

Question: Why do you think they support it?

James Hansen: Well, I think that businesses do prefer an approach in which they know what is going to happen. With cap-and-trade you don't know what's going to happen.

 Recorded on November 30, 2009