In a move celebrated as a victory by leaders of the United Nations Climate Change Conference (COP28) in Dubai last December, agreements were reached to “transition away” from fossil fuels. However, as countries navigate defining what constitutes a transition, the issue of so-called unabated fossil fuel use remains contentious. The agreement notably emphasized “accelerating efforts towards the phase-down of unabated coal power.”
Abatement, in this context, refers to carbon capture and storage (CCS)—the concept that fossil fuel usage can continue as long as the emitted carbon dioxide is captured and stored underground. In the U.S., the oil and gas industries champion this method as a primary solution to the climate crisis. But the feasibility of this approach raises questions.
To understand the situation, it’s important to note that oil, being viscous, often remains in the reservoir, adhering to rocks when extracted. However, employing water, detergents, or gases like CO2 to flood the field can flush out much of the remaining oil. This technique, known as enhanced oil recovery, has been a longstanding industry practice. The U.S. Department of Energy reports that gas injection, accounting for over half of the country’s enhanced oil recovery, has significantly extended the lifespan of fields that would otherwise be depleted. This method is similarly applied in gas fields to maintain pressure and ensure continuous flow.
The oil industry, in recent years, has attempted to rebrand this traditional practice as a climate change mitigation strategy, suggesting that injecting CO2 could prevent it from entering the atmosphere. While theoretically sound, the practice presents considerable challenges.
The principle that “what goes up must come down” is well-known, but the converse is true for fluids and gases due to their ability to migrate through microscopic pores and fractures in even the densest rocks. The U.S. government’s failed proposal for a nuclear waste disposal site at Yucca Mountain in Nevada, despite billions in evaluations, underscores the challenge of ensuring waste containment. The proposed CO2 waste storage, being a buoyant, low-viscosity “supercritical” fluid, has the potential to migrate to the surface and, subsequently, the atmosphere.
Many geologists, myself included, acknowledge potential sites on Earth where CO2 storage could be safely achieved through detailed site characterization. For instance, the U.S. stores military radioactive waste in New Mexico’s low-permeability salt formations, and proposals exist for storing CO2 in sandstones beneath impermeable shales in North Dakota.
However, site characterization is time-consuming, and time is a luxury we don’t have. Evaluations of Yucca Mountain and the New Mexico site spanned over 20 and 14 years, respectively. With the Intergovernmental Panel on Climate Change’s 2018 conclusion that we have only until 2030 to prevent irreversible climate damage, immediate action on feasible solutions is imperative.
Expanding existing carbon capture and storage sites could expedite the process. However, as highlighted by Massachusetts Institute of Technology professor Charles Harvey and entrepreneur Kurt House, nearly all CCS projects in the U.S. actually support enhanced-recovery efforts, maintaining oil and gas production. Thus, each new barrel of oil and cubic foot of gas sold and burned contributes additional CO2 to the atmosphere, not only failing to mitigate climate change but also perpetuating fossil fuel dependency at a critical historical juncture when we need to do the exact opposite.
