Industrial-level commitment and innovation of negative carbon technology key to avoid collapse of coral reefs and millions of deaths.

(Holly Jean, postdoc@UCLA, https://magazine.scienceforthepeople.org/geoengineering/best-case-scenario-carbon-underground/)

If we buy into thinking of carbon removal technologies as substitutes for reducing carbon output, then industrial interests have already won: they have set the narrative and the framing, where carbon capture exists so that they can continue to emit. But we should demand more from these technologies. Industrial carbon capture technologies could instead be used as an extension of decarbonization—mitigation to get us to zero, and carbon removal going a step further to take emissions negative and address some of the climate impacts already being felt. It won’t be easy. But climate science suggests it’s a challenge the Left must take up. Climate change has already warmed the planet over 1°C relative to pre-industrial levels. Paradoxically, cleaning up the air pollution that’s currently masking some of the global warming in the pipeline would raise temperatures another 0.5 – 1.1 degrees.1 This means that if we waved a magic wand and suddenly (1) stopped using fossil fuels, and (2) cleaned up air pollution, we would already be breaching 1.5°C, the amount of warming that most climate advocates have argued for. The carbon budget is not an exact science, but it seems we are hovering at the point where 1.5°C of warming is locked in by what has already been emitted. Put differently, the most recent scientific evidence suggests we have zero to five years before every additional ton of carbon dioxide emitted would need to be compensated by a ton of negative emissions to stay below 1.5°C.2 In fact, the scenarios used in the fifth Intergovernmental Panel on Climate Change (IPCC) report rely on massive amounts of negative emissions to curb warming to 1.5°C, primarily via a method known as bioenergy with carbon capture and storage (BECCS). This led a team of modelers to try and see what it would take to achieve 1.5° without BECCS. Even a scenario where renewables, electrification, and energy efficiency were aggressively pursued—as well as replacing 80 percent of meat and eggs with cultivated meat, flying less, and eliminating tumble dryers—could not eliminate the need for carbon removal. This scenario still required about 400 billion tons (Gt) of carbon dioxide removed via reforestation.3 Reforestation sounds great and green, but it also has the potential to result in dispossession, conflict over land access, and smallholder livelihoods. What about achieving a slightly less ambitious goal of 2°C? Two and 1.5 degrees might not sound all that different, but they are. The difference is one that threatens entire unique coral ecosystems, the homes of five million people4 (including entire countries), and high increases in the frequencies of extreme events. Rapid mitigation could still curb warming to 2°C without the use of negative emissions technologies. But that window is closing fast. If near-term emissions reductions follow the trajectory laid out in the commitments nations made under the Paris agreement, by 2030, 2°C scenarios will also depend upon negative emissions.5 That is, in the next decade, we would have to vastly exceed the Paris promises to not depend upon negative emissions. We aren’t even making much progress towards these Paris targets, which if achieved would still produce 3°C of warming—an amount widely agreed to lead to massive disruptions. This is why negative emissions have become such a useful device for the models. By the end of the century, scenarios for 1.5°C or 2°C envision pulling out ten billion tons (10Gt) per year. For comparison, current levels of emissions are around forty billion tons of CO2 per year. So 1.5°C means not just zeroing out those forty billion tons, but then working to extract another 10 billion on top of that to be net-negative. This would require scaling up current carbon capture and sequestration efforts a thousand-fold.6 Negative emissions help maintain the narrative that although time is running short, we can still stop catastrophic global warming if we act now.7 Once we understand that this inventive arithmetic has been employed to “solve” for 1.5, what do we do? Assuming there will be a complete about-face that puts us on a course towards 100 percent renewables, massive lifestyle changes, and drastic land use change for afforesting millions of hectares in the tropics8 within the next ten years strikes me as not only magical thinking, but thinking that puts many at risk of great suffering. Alternately, accepting that the earth will warm more than 1.5°C means accepting the loss of the world’s coral reefs and the half billion people relying on them, as well as other harms to communities living on the front lines of climate change. So we need to ask: Is there a form of massive carbon removal that could be put towards socially just ends, pulling carbon out of the atmosphere as a form of collective social good? Can it work as an outgrowth of energy democracy? For if such a collection of technologies, practices, and institutions can exist, we should try to build it. Notably, carbon removal at what I’ll call climate-significant scale should not be thought of as a magic wand to wipe carbon away either. For one thing, it will not compensate exactly for emissions. The ocean, for example, currently takes up close to half of the carbon humans emit, and it’s possible that if carbon was removed at large scale from the atmosphere, the oceans would then give off carbon, perhaps replacing half of the carbon that had been removed.9 The prospect of carbon removal is fraught with complexity, and even peril—all of which we have to talk about. The Necessity of Geological Sequestration The best way to remove carbon immediately is through “natural climate solutions,” which employ nature’s processes to store carbon in ecosystems. Sequestering carbon in soil, restoring forests and planting new ones, and protecting wetlands can store carbon. These can forestall some amount of warming, in addition to other benefits for both humans and the environment. Yet while it seems intuitive to simply let nature take up the carbon, carbon was put into the atmosphere unnaturally, and the available scientific evidence suggests ecosystem-based solutions simply don’t scale well enough to contend with the sheer amount of carbon that has been dumped into the atmosphere. Pursued vigorously, reforestation and soil carbon sequestration could each remove a few gigatons per year—for a while. After a few decades, a forest planted to remove carbon reaches a plateau where it becomes saturated and can’t remove any additional carbon, like a bathtub filling up, at which point the already-absorbed carbon must simply be held indefinitely. Similarly, a farm that has transitioned to regenerative practices to store more carbon in the soil can only remove additional carbon for a few decades. Moreover, forests can be ravaged by epidemics or fires, resulting in the sudden release of their stored carbon, which means they are vulnerable to global warming itself. So while these projects can do important work in the near future, we also need to supplement these one-off, land-based carbon removal projects with systems that can continuously remove carbon and store it reliably over centuries — that is to say, with industrial carbon capture with geological sequestration. We need to build systems that capture carbon emissions from sources like power plants factories, or even from ambient air, and transport it to underground reservoirs where it can be stored. There are major technical and social obstacles to this. But these industrial systems for geological storage, used together and sequentially with natural carbon removal, could help ease the path to climate-stable world. Carbon capture and storage (CCS) technology is not a new technology. The first large-scale operations began in the 1970s, and there are around 17 CCS projects operational today. CCS is actually a collection of technologies: those needed to capture carbon emissions at a source; technologies to transport it, usually by pipeline, to a storage site; and technologies to inject it deep underground. It can be used with industrial operations like cement or steel production, with natural gas power plants, with biomass-fueled power plants (BECCS), or in tandem with devices that mine carbon from the air (“direct air capture”). But only in the latter two cases does CCS confer “negative” emissions and actually remove carbon—if it’s installed on a fossil fuel plant, all it’s doing is avoiding some emissions. Its history is tainted by two things: its linkage with the coal industry, and its use for enhanced oil recovery, a technique which injects carbon dioxide into the ground to retrieve more oil from depleted wells. Understandably, this has predisposed people who care about the climate to be very skeptical of the technology and the actors who promote it. Recent experiences with fracking have also made people rightfully wary about injecting large volumes of fluid and gas underground. Once carbon is injected into reservoirs, moreover, it can be difficult to monitor. We need to give CCS another look despite these reservations. Several decades of experience with the technology have improved monitoring technology dramatically and developed best practices for mitigating local risks. The IPCC finds that the local health and safety risks are on a similar scale to those of the current hydrocarbon infrastructure.10 It’s not ideal to replace one hazardous network of infrastructure with another—except in this case, putting the carbon back underground ameliorates the much greater risks of global climate change, which will be felt around the world. In short, it is safer to have the carbon back under the ground than in the atmosphere. The carbon removal technology that’s typically used as a stand-in for negative emissions in integrated assessment models is known as bioenergy with CCS (BECCS). BECCS refers to a system where carbon is captured from a power plant that runs on biomass like switchgrass or poplar trees; the captured carbon is then transported and stored underground. In the real world, BECCS lacks strong proponents. Critics point out that attempts to scale up the use of biofuels have already had major implications for land use, and consequently, for ecosystems as well as for people whose livelihoods depend on the land. One common estimate is that using BECCS to remove 600Gt by 2100 would require dedicated cropland of 430-580 million hectares—equivalent to one-half of the land area of the US.11 Using BECCS at climate-significant scales could have dramatic impacts on biodiversity and freshwater resources. It also can’t be used in every situation: to actually be carbon-negative, BECCS has to meet stringent conditions regarding everything from supply chains to fertilizer. Socially and ecologically just supply chain management requires still more, including fair wages for workers, measures to safeguard biodiversity, and worker or communal ownership of land. These drawbacks and challenges mean that we shouldn’t rely on it as the primary mode of carbon removal, but BECCS could still be useful in specific contexts. A method known as direct air capture, on the other hand, is potentially less land intensive, but it requires massive amounts of carbon-neutral energy. Direct air capture machines absorb carbon from ambient air through a chemical process; then the carbon must be removed and stored underground, as if the carbon had been captured at a power plant. But because direct air capture machines could be located at the site of underground injection, they could have less of an infrastructural footprint. The downside is that it’s currently very expensive, with estimates ranging between $100 and $600 per ton of carbon removed depending on the energy source used.12 So while direct air capture seems to have more potential to remove carbon at climate-significant scales than BECCS, far more work is needed to refine the technology. All of these technologies require both more funding for research and development as well as strong policy incentives to mature, whether that means a robust price on carbon or government pollution controls. On the bright side, perhaps this means they are more likely to be an extension or complement to reducing carbon output rather than a substitute for it. Without heavy state intervention, it is impossible to imagine CCS scaling up over the century to climate-significant levels. The storage capacity of geological reservoirs is sufficient that there aren’t geological limits to carbon sequestration. Eventually, there would be systemic limits for inputs to CCS—land in the case of bioenergy; renewable energy supply in the case of direct air capture—and so the yearly rate of carbon sequestration would be constrained. This means that a full carbon-clean up—that is, if the world wanted to bring greenhouse gas concentrations back to pre-industrial levels, as a restoration or recompensation project—could stretch over centuries. But the near-term practical constraints on CCS are grounded only by political will.