By June Sekera and Neva Goodwin
After decades of casting doubt on climate change and its causes, the fossil fuel industry is now moving towards a new strategy: presenting itself as the source of solutions. This repositioning includes rebranding as “carbon management industry”.
This strategic pivot was exposed at the Glasgow Climate Summit and at a congressional hearing in October 2021, where CEOs of four major oil companies spoke of a “low carbon future”. That future, they believe, would be fueled by the fuels they provide and the technologies they could deploy to remove the planet-warming carbon dioxide their products emit – provided they get government support. sufficient.
That support can happen. The Department of Energy recently added “carbon management” to the name of its Office of Fossil Energy and Carbon Management and is increasing its funding for carbon capture and storage.
But how effective are these solutions and what are their consequences?
Coming from economics, ecology and public policies, we have focused for several years on carbon reduction. We have seen mechanical methods of carbon capture struggle to prove their worth, despite US government investments of over US $ 7 billion in direct spending and at least a billion more in tax credits. Meanwhile, proven biological solutions with multiple benefits have received much less attention.
CCS’s troubled record
Carbon capture and storage, or CCS, aims to capture carbon dioxide as it leaves the stacks of power plants or industrial sources. So far, CCS in US power plants has been a failure.
Seven large-scale CCS projects have been attempted at US power plants, each with hundreds of millions of dollars in government grants, but these projects were either canceled before reaching commercial operation or closed after starting in due to financial or mechanical problems. There is only one commercial scale CCS power plant in the world, in Canada, and its captured carbon dioxide is used to extract more oil from wells – a process called “enhanced oil recovery”.
In industrial facilities, all but one CCS project in the United States uses captured carbon dioxide for enhanced oil recovery.
This expensive oil extraction technique has been called “climate mitigation” because oil companies now use carbon dioxide. But a full lifecycle modeling study of this process in coal-fired power plants found that it releases 3.7 to 4.7 times more carbon dioxide into the air than it removes.
The problem of extracting carbon from the air
Another method would directly remove carbon dioxide from the air. Oil companies like Occidental Petroleum and ExxonMobil are seeking government grants to develop and deploy such “direct air capture” systems. However, a widely recognized problem with these systems is their immense energy requirements, especially if they operate on a climatically significant scale, which means removing at least 1 gigatonne – 1 billion tonnes – of carbon dioxide per year.
This represents about 3% of annual global carbon dioxide emissions. The U.S. National Academies of Sciences predict the need to cut 10 gigatons per year by 2050, and 20 gigatons per year by the turn of the century if decarbonization efforts fail.
The only type of direct air capture system currently in development on a relatively large scale has to be fossil fuel powered to achieve the extremely high heat required for the thermal process.
A National Academies of Sciences study on the energy consumption of direct air capture indicates that to capture 1 gigatonne of carbon dioxide per year, this type of direct air capture system might require up to 3,889 terawatt hours of energy, almost as much as the total electricity produced. in the United States in 2020. The largest direct air capture plant under development in the United States is currently using this system, and the captured carbon dioxide will be used for oil recovery.
Another direct air capture system, using a solid sorbent, uses a little less energy, but companies have struggled to expand it beyond pilots. Efforts are underway to develop more efficient and effective direct air capture technologies, but some scientists are skeptical of its potential. One study describes the enormous material and energy requirements of direct air capture, which the authors say make it “unrealistic.” Another shows that spending the same amount of money on clean energy to replace fossil fuels is more effective in reducing emissions, air pollution and other costs.
The cost of scaling
A 2021 study plans to spend $ 1 trillion per year to increase direct air capture to a significant level. Bill Gates, who backs a direct air capture company called Carbon Engineering, estimated that operating on a climate-significant scale would cost $ 5.1 trillion each year. A large part of the cost would be borne by the governments as there is no “customer” for the burial of the waste underground.
As lawmakers in the United States and elsewhere consider spending billions more on carbon capture, they must consider the consequences.
The captured carbon dioxide must be transported somewhere for use or storage. A 2020 Princeton study estimated that 66,000 miles of carbon dioxide pipelines would need to be built by 2050 to start approaching 1 gigatonne per year of transportation and landfill.
The problems associated with burying the high pressure CO2 underground will be analogous to the problems encountered by the nuclear waste site, but in considerably larger quantities. The transport, injection and storage of carbon dioxide entail health and environmental risks, such as the risk of broken pipes, contamination of groundwater and the release of toxins, which particularly threaten the historically disadvantaged communities most affected. of pollution.
Bringing direct air capture to a scale that would have a significant impact on the climate would mean diverting taxpayer funding, private investment, technological innovation, scientific attention, public support and political action difficult to mobilize far from the essential work of transition to non-carbon energy sources.
A proven method: trees, plants and soil
Rather than placing what we see as risky bets on expensive mechanical methods that have a difficult track record and require decades of development, there are ways to sequester carbon that rely on the system we already know we have. it works: biological sequestration.
In the United States, trees already sequester nearly a billion tonnes of carbon dioxide per year. Better management of existing forests and urban trees, without additional land use, could increase this figure by 70%. With the addition of reforestation of nearly 50 million acres, an area the size of Nebraska, the United States could sequester nearly 2 billion tonnes of carbon dioxide per year. This would be equivalent to about 40% of the country’s annual emissions. Restoring wetlands and grasslands and better farming practices could sequester even more.
Per ton of carbon dioxide sequestered, biological sequestration costs about a tenth of what current mechanical methods do. And it offers valuable secondary benefits by reducing soil erosion and air pollution, as well as urban heat; increase water security, biodiversity and energy conservation; and improve watershed protection, human nutrition and health.
To be clear, no carbon removal approach – neither mechanical nor biological – will solve the climate crisis without an immediate transition from fossil fuels. But we believe relying on the fossil fuel industry for “carbon management” will only further delay this transition.
June Sekera is Principal Investigator and Visiting Scholar at The New School. Neva Goodwin is Co-Director of the Global Development and Environment Institute at Tufts University. They wrote this piece for The Conversation, where it first appeared.