Massive seaweed farms that suck carbon dioxide out of the atmosphere and counteract ocean acidification. The widespread adoption of carbon fiber technology that extracts CO2 from the air and turns it into cars and other industrial products. Concrete manufacturing that is carbon-negative rather than the energy-guzzling Portland cement used today. And giant chiller boxes installed in Antarctica that super-freeze the already frigid air there, producing “CO2 snow” that can be sequestered in the continent’s massive ice sheet.
These and other ideas represent what Australian scientist Tim Flannery calls “third way technologies” — safe methods to reduce atmospheric carbon dioxide levels that could be adopted in concert with large-scale reductions in greenhouse gas emissions.
Flannery, former head of the Australian Climate Commission, lays out these ideas in his latest book, Atmosphere of Hope. In an interview with Yale Environment 360, he explains that unlike risky geoengineering schemes, these approaches “strengthen Earth’s own self-regulatory system by drawing C02 out of the atmosphere in ways the planet naturally does already.” Flannery, who says he is heartened by the increasingly widespread adoption of wind and solar power, believes that if the world community can develop third way technologies quickly enough and harness the political and economic will to apply them at scale, there may yet be light at the end of the climate tunnel.
Yale Environment 360: In your earlier book, The Weather Makers, you forecasted a bleak future if we don’t change course. Yet you seem guardedly optimistic in your latest book.
Tim Flannery: I’m definitely more hopeful and that’s only happened in the last two years. I was pretty despairing after Copenhagen. But some things have happened recently that have given me new hope. One of the most heartening has been the change in public knowledge of climate change and attitudes toward it. When I wrote about climate change ten years ago I had to use a slide presentation with graphs showing the increase of C02 concentrations and increasing temperatures and all the rest. That is because back then the major impacts of climate change had not really hit yet. Whereas when I go around the world and speak now, everyone has a story about how climate change is impacting their lives. There is still a small band of deniers. But they are definitely in the minority now. Climate change is a lived experience of most people.
‘There is still a small band of deniers … [but] climate change is now a lived experience of most people.’
e360: You cite in the new book a report by the International Energy Agency saying that global carbon emissions had stopped rising between 2013 and 2014. What is the significance of this?
Flannery: That is the second bit of good news, the first being the increasing awareness of the issue. If the IEA data is correct, it’s a landmark achievement, to see global emissions from energy sources stall, and also to see the decoupling of fossil fuel emissions from economic growth. The global economy grew, but the emissions from energy sources — everything from transport to electricity production — stalled at 32.7 billion tons of emissions. That is really unexpected. Nobody thought that we would see that as early as we have.
e360: What factors have caused this leveling of emissions?
Flannery: There are two big factors. One is the incredible success of wind and solar in terms of penetration into the market. And the second has been the billions and billions of small actions that people like you and I have been doing, changing our light bulbs, making our housing more energy-efficient, cycling to work. These sorts of things have cumulatively been having a huge impact. I was skeptical whether these actions would all add up to anything. Well, they have now added up to something really huge.
e360: Some scientists have proposed geoengineering schemes like seeding the high atmosphere with sulfur or adding iron to the sea as ways to cut down on warming. Are these bad ideas?
Flannery: Yes, they are really bad ideas. Take injecting sulfur into the stratosphere [to deflect sunlight]: the problem is just going to fester under that sulfur layer. The C02 is going to continue to build up and poison our oceans with acidification. Modeling has shown how strongly the South Asian monsoons would be influenced by such a move, and one to four billion people depend on those monsoons for their survival.
‘The scary thing about these geoengineering ideas is that they are really being taken seriously now.’
The scary thing about these geoengineering ideas is that they are really being taken seriously now. And they can be done unilaterally, there is no global treaty regulating their use. There are four separate teams working on various geoengineering possibilities in China alone. China is going to be seriously impacted by climate change — we know that, the government knows that, and they are looking at the possibility of using some of these Band-Aid solutions to derive some short term benefit in a way that would have massive long term consequences for many people around the planet.
e360: In your book, you talk about what you call “third way technologies.” What are these, and how do they differ from geoengineering?
Flannery: Some of them have been considered in the past as forms of geoengineering. But we need to be very careful about our language in this. I had to invent that term— third way technologies— to describe a basket of approaches that work in synergy with the planet to help reinforce the way the Earth system stabilizes itself. And they do that by drawing carbon dioxide directly out of the atmosphere and then putting it into something useful or storing it somewhere safely. So it is very much a functional distinction between geoengineering’s Band-Aid solutions and the third way technologies, which strengthen Earth’s own self-regulatory system by drawing C02 out of the atmosphere in ways the planet naturally does already, or in ways that simulate that.
e360: You write about two categories of third way technologies, the biological and the chemical. Could you talk about the biological approach?
Flannery: For example, reforestation is really basic. Trees are just congealed carbon dioxide. So when you plant a forest, what you are doing is you are using the power of the sun harnessed by photosynthesis to draw C02 out of the atmosphere and congeal it as living trees. You can also then take some of those plant products that you grow and turn them into a form of carbon that will last longer, that won’t rot away as quickly by converting it to biochar. Biochar is a form of charcoal derived from various plant products. You can plow it into your agricultural soils or store it somewhere and it will stay there as a mineralized form of carbon for many years. The biochar industry is still very small. In 2013 it was only producing a thousand tons of salable product, so it is an option that is yet to grow to scale.
e360: You are really hopeful about seaweed farming. How would that work?
Flannery: Seaweed grows at 30 to 60 times the rate of land-based plants, so it can draw out lots of C02. One study suggests that if you cover 9 percent of the world’s oceans in seaweed farms, you could draw down the equivalent of all our current emissions — more than 40 gigatons a year — and grow enough protein to feed a population of 10 billion people. That’s a huge opportunity.
‘Seaweed grows at 30 to 60 times the rate of land-based plants, so it can draw out lots of C02.’
Seaweed farms can also reverse ocean acidification. Off the coast of China, there are about 500 square kilometers of seaweed farms that are used to produce edible seaweed for the food market. They have been very well studied, and we’ve seen there that pH can rise as high as 10 around those seaweed farms. At the moment with an acidified ocean it is 8.1. You could buffer oceans and they are fantastic places for growing fish, shellfish, or prawns, just because of that buffering impact. But you then have the problem of what to do with all that seaweed. You certainly don’t want it just sitting there and rotting away. One of the proposals is that bio-digesters be used. These are very familiar to famers, the kinds of things you put your agricultural waste in and generate methane, which you can use to produce electricity.
e360: Turning to the chemical third way technologies, you write about carbon-negative concrete. What is that?
Flannery: It is a kind of concrete that uses different components for the cement from conventional concrete. It doesn’t emit C02 during the manufacturing process. As the concrete sets and matures, it actually absorbs C02 into its structure. So it is carbon-negative and its manufacturers claim that it is lighter, stronger and more durable than concretes made with Portland cement. But because it is a new product, it doesn’t have a track record. No one is going to build the Brooklyn Bridge from it just yet, because we aren’t sure how it is going to stand up. But there are a lot of low-risk uses for concrete that we can begin with as we try to grow that industry. And it is incredibly important because concrete manufacture accounts for about 5 percent of global emissions.
e360: Olivine is one of the most common rocks in the Earth’s crust with the ability to chemically bind with CO2 in the atmosphere. How could this be used?
Flannery: There is a roofing company in the Netherlands that makes a paint with an olivine based rock that takes C02 out of the atmosphere directly into your roof. There are also people who are using crushed olivine as a soil amendment, absorbing C02 as the rocks decay. There are proposals to create beach sand from olivine. There are other proposals to use olivine to treat the exhaust from shipping, then put it in the sea to help take C02 out of the waters, in a similar way that seaweed farming does.
e360: You report in your new book that fuels, carbon nanofibers, and certain types of plastics can be made directly from C02 in the atmosphere. But these are futuristic possibilities. Won’t it take a long time to get these technologies up and running at scale?
Flannery: It’s still at an early stage, but all indications are that the plastic industry is set to be transformed by these technologies as we move away from fossil fuels. And the carbon fiber possibilities are just astonishing. If you want a very light, very strong material, carbon fiber is what you use. At the moment it is very expensive to manufacture. But just a month ago a major breakthrough was announced by a company that devised a way of manufacturing carbon nanofibers directly out of C02 in the atmosphere at one tenth of the production cost of other methods. As carbon nanofibers become cheaper to manufacture, they will start competing directly with steel and aluminum, both of which are very energy intensive and produce lots of emissions.
‘A company has devised a way of manufacturing carbon nanofibers directly out of C02 in the atmosphere.’
e360: There are already ways to take C02 directly out of the atmosphere or out of the exhaust stream from power plants. But the problem is where to safely store the captured greenhouse gas.
Flannery: Previously, carbon capture and storage was conceived of as something that you would apply to the end of a coal powered power plant, capture the C02, and store it in bedrock somewhere near that plant. But if you put C02 under the ground, the C02 remains buoyant, the stuff is always trying to escape, to go upwards because it is a gas. In the oceans, however, things are quite different. Water pressure at two or three kilometers depth is sufficient that C02 remains stable. And if you try to bury it even in shallow marine sediments it becomes a solid on its own.
When you think about it, the ocean floor is where most of that excess C02 is destined to reside, or most of it anyway over geological time. The C02 is absorbed into the oceans, it is turned into a carbonate on the bottom of the sea as limestone or whatever. So the idea that we should pump C02 into deep ocean sediments at 2 or 3 kilometers is really mimicking what happens over the longer term anyway and it provides a stable environment for carbon to be stored.
e360: One of the most surprising ideas in your book is the proposal to create C02 snow in Antarctica. Could you talk about this?
Flannery: C02 falls out of the atmosphere as snow at -75 degrees Celsius, and sometimes it reaches -90 degrees Celsius over the Antarctic icecap. So C02 is already falling as snow out of the air at times in Antarctica. The thing is it doesn’t get buried or stored anywhere. As temperatures warm, it sublimates and goes back into the air. So the proposal for the Antarctic is that you would build some big chiller boxes, say 100 yards cubed, you would power them using wind energy, which is already being used by the research stations in Antarctica for their electricity generation. You need about half the installed wind power that Germany presently has to run these chiller boxes to capture a gigaton of C02 in the form of snow. So the idea is that you would put the chiller box out, you’d cool the air a few tens of degrees, the C02 would fall out as snow, you would bury it under ice and it would stay there. That is a very exciting option.
e360: Most of these third way approaches are going to require a tremendous amount of research and development, not to mention time, before they become economically viable. Who is going to pay for this? And can we really wait until all the details are worked out?
Flannery: If you look at the development pathways for wind and solar, you see how long they are. It has taken three or four decades to have gotten where we are today. And it is going to be the same for any of these third way technologies.
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Some of them are going to be a bit more self-propelling because they will be much more profitable than others. So for example, I can imagine carbon nanofiber manufacture really taking off through private investment. But others such as storage of atmospheric C02 under the Antarctic ice, they may need some sort of government assistance.
e360: Why has it become necessary to develop these radical new approaches?
Flannery: We’re in a really difficult position right now. Even if we stop all fossil fuel use today, the planet is going to warm by one-and-a-half degrees within decades. The reality is we are seeing significant damage at one degree, which is near where we are now. We’re committed [by inertia in the system] to 1.5 degrees. A 1.5 degree rise is already looking like it is going to be too much. Sea level rise is going to be tremendously destructive. So the argument is that we need to do two things at once. We need to reduce emissions as fast as we can, and the second is to start investing now in these new technologies, in research and development.