(Bloomberg) – Humans can emit about 1,000 more gigatons of carbon dioxide before we conclude a global average temperature rise of more than 2C before the Industrial Revolution, the threshold that scientists warn of climate changes becomes dangerous. A planet higher than 2C may trigger run-off effects that would make things even worse.
The new year will arrive with average temperatures already up around 1.2C. More than half way there. Every year, we release more than 35 gigatons of CO₂ and increase its air concentration by about 2.5 parts per million. Keeping our collective fever under the 2C targeted by Paris Agreement signatories or even better, below their preferred 1.5C – already looks very difficult.
Decarbonising our energy and transport sectors as soon as possible remains the focus of all serious plans to deal with this danger, including President-Elect Joe Biden’s plan, but everything else that has ever been suggested must be considered . It is an inevitable fact that we will add more CO₂ to the atmosphere before we can achieve a carbon-neutral technological foundation. Given the serious danger, we need to try every possible mitigation.
These practical possibilities include technologies to remove carbon from the atmosphere and seize it on or inside the Earth. Sometimes called carbon stripping or negative carbon, these projects now look more appealing than ever, even necessary. Old objections that the exact idea of carbon removal will encourage people to tackle new sources of emissions quickly are no longer fulfilled when we are at this point.
Without doubt, biological are the quickest and easiest ways to remove carbon from the atmosphere: reforestation, regenerative agriculture, seaweed and seagrass, aquaculture, wetland restoration, and so forth. But there may not be enough room for natural solutions to do the job on its own. In the two centuries since industrialization began, we have burned the remnants of millions of years of forest growth. For the biological world to draw that fossil carbon back down, it could take the land and sea of two Earths.
So it makes sense to discuss technology that we haven’t quite mastered: direct air capture, or DAC. This process involves using machines to filter CO₂ out of ambient air, then removing the trapped gas – either by injecting it underground, binding it to a rock, or using it for industrial use . Towing down machines, if scaled up to a significant portion of the need, would help us a lot.
Capturing CO₂ out of the air is a sophisticated industrial process, and can be water and energy intensive. Translation: It’s expensive. Prototype systems cost as much as $ 1,000 per ton caught. But these costs could soon fall to half that, and there are hopes of eventually reaching $ 100 a tonne.
The mechanical operations involved are already employed in large-scale industries. Everything from storage and transportation methods to fans and absorber beds can be adopted from existing technologies rather than being invented from scratch. Ironically, it is the old oil companies that already have some of the key technical skills and infrastructure that could be adapted to this work.
Many companies are already working on systems and have prototypes in place that could be increased. Climeworks AG in Switzerland has built the first commercially-operated DAC facility, and recently entered into a partnership with an Icelandic geothermal factory to capture CO₂ and bind it to underground rocks. Carbon Engineering Ltd. and Global Thermostat LLC also follow DAC designs. This emerging industry is underpinned by academic research at places like Arizona State University’s Negative Carbon Emissions Center, whose director, Klaus Lackner, guided me through the current state of the technology.
DAC is sometimes compared to the auto industry. A car, like carbon dismantlers, is complicated and expensive. And yet we build millions of them every year, because we like what they do. There may be an even better comparison with a sewage treatment plant – a costly tool for dealing with waste that we cannot ignore. We spill billions of tonnes of carbon waste into our life support system; as with our other waste, it needs to be disposed of properly if we do not want to poison ourselves. That cleaning needs to be paid for, whether for street sweepers or air scrubbers.
The problem is not technical viability but the huge investment needed to build something that may not generate profit. There is promise in developing liquid fuel made with CO₂ trapped or turning the basic greenhouse gas into a feed for various carbon fibers. But the amount of carbon we need to draw down is far greater than these industrial uses, and capital seeking the highest rate of return will not be invested.
Everyone would benefit from a stable climate, but if the market is still the only way to calculate value, there is no way to properly charge people for keeping the biosphere viable. The answer here is simply to view this technology as a public utility that creates public benefit, such as roads, national defense, fresh water or sewage disposal – and pay for it.
A payment method that could come into effect here would be quantitative carbon reduction. Central banks could fund the production and installation of a growing fleet of CO₂ scrubbers, just as they provide liquidity to the financial industry in times of need. The effort could also become such a large program of work, it could be something like a job guarantee, with planetary and individual benefits. There is so much work to be done here. It would take a lot of government investment – and a lot of labor. We have both of these, or we can if we want them.
All types of DNS will also need a lot of electricity, which would have to be clean renewable energy otherwise the point of the effort would be lost. A large DNS enterprise may need as much as a few percentage points of all the electricity generated, one that equates to a significant percentage of need. This sounds extreme, but consider right now that 2% of the world’s electricity supply is wasted in creating Bitcoin. A similar amount directed towards saving civilization might reasonably be considered.
The carbon and building material costs of so many units would have to be calculated in the overall cost-benefit equation, but these factors apply to everything we manufacture, even for essential climate solutions like lithium-ion batteries and solar panels . We seem to think those costs are worth it. In the case of DAC, the removal of CO₂ from the air is pure, without potential adverse side effects. We won’t be in danger of overdoing it and creating a new ice age anytime soon! And if we ever got to that point, it would be a nice problem to have.
While other methods are easier to get started and cheaper to ramp up to significant capacity, they all have problems. In a practical emergency, direct air capture could become one of the strongest hands. It’s worth looking into.
Robinson writes science fiction in Davis, Calif. His latest novel is The Ministry for the Future. This column does not necessarily reflect the views of Bloomberg LP and its owners.
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