Question: What prompted you to become so involved in the study of climate change?

Answer: By the late 1990s the science was looking so dismal. If you read the major scientific weeklies such as Nature and Science, you could see this emerging picture that this was becoming a very, very substantial issue. And of course Australia wasn't pulling its weight. We hadn't ratified the Kyoto Protocol; we had a government that was totally dismissive of the issue. And I just felt that it needed better input and the only way to achieve that was going to be public education. So I've devoted the last seven or eight years in Australia just to increasing public awareness of this issue.



Question: Why did you write The Weather Makers?

Answer: I just wanted to lay out the science for people in as unbiased a way as I could so they could inform themselves and make up their own mind.



Question: You paint a very grim picture for much of the book, but at its conclusion you're hopeful. That was written in 2005. Has your perspective changed for the better or worse since then?

Answer: Could I just say that you say it is a grim read, but it is actually a very objective read of the science as it s published in the world's leading journals. So that is really as objective a read as you could get as of 2005. I really did work hard not to make it alarmist and not to be putting in disreputable, highly hypothetical stuff, you know? And to give the risk factors and whatever else.



Question: But it's worrisome.

Answer: It is extremely worrisome. Next month the Intergovernmental Panel on Climate Change will produce their Synthesis Report, and that has even worse news. So the science is getting more dire. We now know that there's enough greenhouse gas in the atmosphere already to carry a high risk of probability of dangerous climate change. That's a 20-percent-plus risk. So we're already facing that situation and we had hoped that was a little bit further out. When you're dealing with a problem like climate change, we're working with timelines that are not human-made. They're made by the biosphere. They're dictated by the biosphere, so our actions have to be equally tough. Thankfully, some people are producing plans which give us a reasonable chance of avoiding dangerous climate change, and foremost among them is Gov. Schwarzenegger in California, who has put exactly the right targets in place and is pursuing that whole issue with vigor.



Question: He's doing that in California; is that level of reductions (to 1990 levels of carbon emissions by 2020, and 80 percent below them by 2050), if they're able to achieve them, what is needed worldwide?

Answer: It is. We need 80 percent plus in the next 40 years. What that means is we won't be able to be using fossil fuels as we are today 40 years from now, so no more oil, no more gas — or very little anyway — and no more coal unless it's burned through these new clean technologies. So that is a formidable obstacle but not impossible, and it's not one we can afford to fail on, either.



Question: You talked about the clean-coal technologies (in which the carbon dioxide is captured and stored underground). Are those fairly close to implementation?

Answer: It's certainly looking feasible. The cost is a big question. The best figures that I have are that in the Australian context we'll need a carbon tax on the order of $70 a ton to make them viable, which is really high, given our present understanding would be about what it would take, and of course they're only going be viable where the geology's right. So the new clean-coal technologies are very much like wind and solar and so forth in that they're limited by particular circumstance. We only have wind power where we have good wind availability and solar where we have plenty of sunlight, we only have clean coal where the geology's right for the sequestration of the carbon dioxide, so it's not going to be a cure-all and it's not going to replace coal use because there's plenty of the world where it's not going to be applicable.



Question: What might a region like New Mexico look like to our children in 2050? How might their lives be different?

Answer: 2050 is a long way out, and it depends very much on the action we take. But could I just give you a very local view that you might want to expand into that global view. In Australia we have one large river system called the Murray-Darling river system, which this year is now in crisis, and it supplies water to a city of 1.1 million people called Adelaide. And we grow 40 percent of our projects on that river system. By the end of this summer that system will be in collapse by the look of it. We face the very real possibility of having bottled-water distributions in Adelaide. That's the sort of crisis that you could easily imagine happening in your part of the world, where water is a key issue, because as our climate warms, rainfall is decreasing in dry areas and stream flow is decreasing even more than rainfall is. The really frightening thing is that we had average rain over the Murray-Darling basin this year, and it's still done nothing to avert this disaster.



Question: Explain how if you have average rainfall, climate change could cause a river system to collapse.

Answer: The heat from the atmosphere is transferred into the soils, giving us warmer soils, and water evaporates more readily from warm soils than cold soils, and plants are more stressed by the warmth, so they need to use more water. So if for example, a certain amount of rain falls in that area, in the past a separate proportion of that might have contributed to stream flow. Today we have a 15 percent decline in rainfall on long-term average. Which equates to a 70 percent decline in stream flow. And of course it's the stream flow that we need for irrigation and for towns and cities.



Question: You and other scientists have said we have one to two decades to act to reduce emissions in order to avoid catastrophic change. You mentioned a littler earlier the new IPCC report. Does that change things?

Answer: Absolutely. You've picked up on the key issue. We used to think we had 10 years because the threshold to dangerous climate change looked like it was about 10 years away. That's because we weren't measuring what's called the carbon-dioxide equivalent accurately in our atmosphere. The new IPCC report does measure that accurately, and we now know that we're already over the threshold. So there is no more time. We must act now; the 10 years is up.

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Question: So what does that mean, that we have to act now?

Answer: We're already in overshoot; we're already in the dangerous zone. So the answer to the question is as soon as possible. But if you're talking about global targets, we need to have effectively decarbonized the global economy within the next 40 years to have a chance of staying in about 2050 below that dangerous threshold. That won't be enough. We've got to decarbonize our economy. We've got to maximize our use of tropical forest and of the agricultural pyrolysis-based technologies in order to give us a chance to stay below that dangerous threshold by the middle of the century. What that means is that we've got to live with unacceptable risk for the next probably 30 to 40 years. What I consider unacceptable risk. But unavoidable risk.



Question: You talk about dangerous thresholds. Tell us what those are.

Answer: No one can say exactly what part of Earth's climate system will be stabilized or where the big threats will come, and I must say I've learned my lesson in trying to project what they might be and getting it wrong. I didn't predict in Australia the urgency with which the water issue would become evident. So I don't know which of the stresses are going to be the important ones in the next decade. But what we've got to watch out for is stresses that do to the human species what we see in the natural world, which is change their resource availability to the point where they become endangered.

We live in a global civilization and we are intimately connected one to the other around the world. So changes in Afghanistan, as we see, have big impacts in the U.S. instantaneously. We all live in this global society, so if the stress is sufficient to start causing the breakdown of global law and order and global trade, we will see very unfortunate consequences, I think.

One of the reasons I've been such a strong advocate of the great global treaties such as Kyoto is that even though they're weak and they're not doing what we need in terms of emissions reductions, they at least offer us a venue to keep talking as this threat increases, rather than fighting. Where the big danger is we'll fall to squabbling among each other over a diminishing resource base. And that's the kiss of death, that's the moment you lose the capacity to deal with this problem because we need to be able to cooperate to deal with this problem.

Question: Climate scientists say we're committed to a certain amount of climate change through 2050 no matter what we do because of the amount of carbon that's in the atmosphere already and will remain there. But what if someone came up with the technology to take carbon out of the atmosphere or a geo-engineering solution to cool the earth? Would that make a difference?

Answer: The short answer is nobody knows, because we don't yet know whether we've crossed that threshold for dangerous climate change. And that's the point where those positive feedbacks kick in to the point where the climate changes regardless. So let's just take a step back from that and look at the other question, which is really what is the amount of climate change we'll experience this century as a result of the greenhouse-gas burden already in the atmosphere. The standing stock of greenhouse-gas pollutant in the atmosphere is on the order of 200 gigatons that's built up since 1800, since the beginning of the Industrial Revolution. If you look at how you might draw down that standing stock of gas pollution, we've got several tools in the toolkit that can do that already without resorting to some high-tech response.

The first is the regrowing of tropical forests. It's entirely possible that 20 years from now we'll be regrowing enough forest worldwide to be pulling 10 gigatons of carbon out of the atmosphere per annum. Now that might be the upper bounds. But that is 5 percent of the standing stock of the pollutant that we could be drawing out of the atmosphere per annum were we to get carbon trading up and make this happen, and the way that you would do that, I think, is just putting a computer in every primary school in the tropics. So that you could go onto Google Earth and look at a thousand villages in the Amazon and have them all ranked and have a little story about their head man. And then you'll go to e-Bay and buy yourself $10 worth of carbon sequestration in Village A that looks good. So those sort of solutions are there right now; all we need is to get the computers into the villages and get a program in place, and that would be the most cost-effective way of drawing the gas out of the air, cheaper than any engineering solution we could imagine.

The second big area where we could do that is in agriculture. The development of the pyrolysis-based technologies, which involve the partial burning of crop waste, allow us to sequester by 20 years from now, even less, 10 gigatons of carbon or thereabouts in our agricultural soils every year. So between the tropical forests and agricultural initiatives we have the potential to be drawing down the standing stock of the pollution by 10 percent per annum in just 20 years' time. So once you develop those technologies to that scale you can see that the extent to which you're committed to dangerous climate change is perhaps not as great as we previously imagined.



Question: Do we have the technology to decarbonize by the time we need to?

Answer: Yes, we do, and the Californians are rapidly proving that, with multibillion-dollar investments now in concentrated P.V. (photovoltaic) technologies and in solar-thermal technologies to generate baseload electricity. That is a quantum leap. We're already there with that. We're there with wind. We are getting very close to being there with geothermal power. So I'm absolutely confident that we'll get there.



Question: In The Weather Makers you mention the geothermal stores in southern Australia. How close are those to being utilized?

Answer: The projections are that by 2015 we'll have a 500-megawatt plant operating there if all goes well. That's one company among many and of course the geology in southern China is very prospective for this sort of energy source, so we shall see where we'll be in 10 years time with that process.



Question: Is nuclear technology part of the solution?

Answer: Yes it is, and it will be particularly in the short term. And there are some things that need to be done to make nuclear technology proliferation-proof, which are eminently doable, eminently feasible. Particularly with the refining of uranium and the concentrating of it, that will make that technology even more environmentally friendly.



Question: New Mexico has a target of reaching 2000 levels of GHG by 2012, 10 percent below them by 2020, and 75 percent below 2000 levels by 2050. Will those kinds of reductions avoid the dangerous change you're talking about, or they're not quite good enough?

Answer: Yeah, it's a good start, but not quite enough. But you know, 2050's 40 years out, and if you look at the world as it was 40 years ago, it's sort of impossible to imagine where we'd be today. And likewise it's going to be impossible to imagine where we'll be in 2050, so I'd say that that's a great start. If I was in New Mexico I'd be tightening up the short-term targets first rather than the long-term ones because they're the ones that really bite and will cause the sort of changes that will build on each other and will give us the opportunity to reach those more aggressive targets 40 years from now. And of course people are going to make a lot of money out of this. We already know the new oil barons are going to be the people who get into renewable energy. That's been evident for a long time.

Question: New Mexico has joined the Climate Registry and Western Regional Climate Action Initiative, which involve cap-and-trade processes, (members have limits on emissions, but they can exceed those limits by buying credits from other members who are under their limit). Are cap-and-trade processes part of your solution to reduce emissions?

Answer: You Americans should be really proud; you invented the system of trading in pollutants that's been so effective dealing with the first global crisis. Richard Sandor at the Chicago Climate Exchange invented sulfur trading, and without sulfur trading we would have had acid-rain problems ongoing for much longer than they in fact were. So carbon trading and cap-and-trade systems are very well understood and were pioneered in your country and clearly are going to be part of the solution. They're more cost-effective than taxes. It depends on how wide you make them. My view would be they should only be dealing with the fossil fuels — leave agriculture and forestry out of it — because it's very different sort of carbon processes there. In some of the systems such as New Zealand they're developing cap-and-trade processes — and in Australia we're talking about it - which are good but involve forestry and agriculture, so we'll be accounting for the whole of the carbon and presumably allowing trade to occur between say fossil fuel offsetting forestry or whatever. I think that's a mistake, because the fossil fuels are ancient carbon, and once that's released in the atmosphere it's very difficult to get back permanently. We can only do it temporarily through tropical forests or even soil agriculture. So we need separate systems, I think. We can't allow trade across the whole carbon system.



Question: James Lovelock, the originator of the Gaia theory, has advocated a proposal to thread the oceans with pipes to bring deep water up to the surface and grow algae to soak up carbon dioxide. What do you think of those types of proposals?

Answer: I think at the moment I would certainly think it's worth investigating them and continuing to look at feasibility but I think they're going be an expensive option. And I'm not sure how viable they'll be. The big problem with the oceans has not been getting the algal blooms to happen. It's been getting the carbon to sink. So I don't know how the pipes are going to achieve that. That's where, yes, it's a good idea and a good technology to start but we somehow have to make that breakthrough that actually lets us sequester. We can capture it from the atmosphere using the algae, but how do we sequester it? That's what's held back all the ocean stuff.



Question: You mention in The Weather Makers that China and India are increasing their emissions as their industries develop and that the Earth's population will increase from 6 billion to 9 billion by the middle of the century. Given such grand numbers, should individuals bother to act? Can individual actions make an impact?

Answer: Yes, of course they should; it's critically important that they do. This is a problem all of us face. It's a collective-action problem. I think we should all be doing what we can. But at the moment, there are also big political challenges. China has recently announced, for example, that they will, if the developed world agrees on particular targets on emission reductions, China will join. So the ball's in our court now in the U.S. and Australia. If we ratify Kyoto and we manage to broker a treaty that has very aggressive reductions globally, China will be part of it. At that sort of level politically, it becomes ever more important to be active.



Question: What sort of goals or organization are you looking for from the U.N. conference on climate change at the end of the year?

Answer: Given that it's being held in Bali, I think there will quite rightly be a focus on forests. And I hope we get the first building blocks in place for a very aggressive tropical-forest program for sequestering carbon and growing tropical forest.

Question: Could you explain the pyrolysis technology and how far away that technology might be from implementation

Answer: It's the partial combustion of any biological material in the absence of oxygen, or partial absence of oxygen. So what you do is, you've got a corn crop, and you can harvest the crops, you can take the crop waste, or the corn stalks, and put them into this pyrolysis machine and at one end of the machine you'll get a synthentic gas that could be burned to generate electricity and put back in the grid or you could get a crude-oil substitute to be taken away in a tanker and refined and at the other end you get a charcoal. Now the importance of charcoal is that it's an inert carbon — you know, C-14 dating relies upon the idea that charcoal lasts a long time in the soil. The crop waste is much more volatile than that, so the corn stalks'll be gone in a year. ... But the charcoal will last for thousands of years. So you take the charcoal out of the back end of the pyrolysis machine, plow it back into your fields, where it increases soil fertility and helps with soil structure and soil moisture retention and so forth, so you get a better crop next year.

So all of a sudden with pyrolysis, the farmer has got four crops instead of one. He's got his corn that he sells, he's got synthetic gas that he can combust to make electricity or crude-oil substitute, he's got carbon that he's paid to sequester in the ground, that's crop No. 3, and he's getting a better return. So he's got four valuable assets. Those are revolutionary technologies that are going to be very important in future. For them to get up and running we need a carbon price of around 37 U.S. dollars a ton because there are some built-in costs in terms of the machinery and also in terms of the cost of forgoing the combustion of all that carbon.



Question: Explain the carbon price:

Answer: Say a farmer produces a ton of charcoal using this process; if he gets around 40 U.S. dollars just for plowing that charcoal into his fields, it then becomes economically viable for him to pay back the cost of his machinery in a reasonable timeframe and also start making a profit. We need a carbon-trading scheme that allows that charcoal to be sequestered and the cost has to be around that $40 a ton to make that happen. Now when you look at clean-coal technologies as we talked about earlier, we need a cost of around $70 Australian a ton — or 60 U.S. — so it's higher than it is for pyrolysis-based technologies.



Question: If things get really bad, in The Weather Makers you pose the possibility of an & quot;Earth Commission for Thermostatic Control. & quot; How likely do you think such a thing is?

Answer: I think people are smart enough to avoid that. But we can't let the problem get so severe that we have to take absolutely drastic measures, because at that point you do lose a lot of autonomy. That's what I was trying to say in that. The coal lobby and the oil lobby by holding back action is making it more likely that we will have to take drastic action that would curtail liberties in a way they'd hate. So it's better to act early.



Question: What are five things individuals can do to make a difference, without spending a lot of money?

Answer: In your part of the world, I'd be looking certainly at solar hot water, a solar hot-water system.

Question: How much does something like that cost, though?

Answer: Depends on government subsidies, but in Australia it's generally around $2,000. But if you've got to buy a new system anyway, that's probably going to be $1,000. So just when you're system looks like it's getting old or unreliable, move to solar.

When you think about buying a new car, let efficiency be a really important part of your decision-making.

At the household level, just basic energy audit, you know? Do you really need that second fridge? Can you get by with that standby? Just those basic little things. Save yourself a little money and do the planet some good.

Finally, voting. If people are asking for your vote, you've got the right to ask them questions, after all you're sort of employing them for the next four years to represent your country, aren't you?