Opinion: Not All Carbon-Capture Projects Pay off for the Climate – We Mapped the Pros, Cons of Each

February 21, 2024

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by Volker Sick (University of Michigan/Canadian Biomass Magazine) Capturing carbon dioxide from the air or industries and recycling it can sound like a win-win climate solution. The greenhouse gas stays out of the atmosphere where it can warm the planet, and it avoids the use of more fossil fuels.

But not all carbon-capture projects offer the same economic and environmental benefits. In fact, some can actually worsen climate change.

I lead the Global CO₂ Initiative at the University of Michigan, where my colleagues and I study how to put captured carbon dioxide (CO₂) to use in ways that help protect the climate. To help figure out which projects will pay off and make these choices easier, we mapped out the pros and cons of the most common carbon sources and uses.

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Some carbon materials can be replaced with carbon-free alternatives, such as using renewable energy to produce electricity. However, for other uses, such as aviation fuel or plastics, carbon will be harder to replace. For these, technologies are being developed to capture and recycle carbon.

Capturing excess CO₂ – from the oceans, atmosphere or industry – and using it for new purposes is called carbon capture, utilization and sequestration, or CCUS. Of all the options to handle captured CO₂, my colleagues and I favor using it to make products, but let’s examine all of them.

CCUS best and worst cases

With each method, the combination of the source of the CO₂ and its end use, or disposition, determines its environmental and economic consequences.

In the best cases, the process will leave less CO₂ in the environment than before. A strong example of this is using captured CO₂ to produce construction materials, such as concrete. It seals away the captured carbon and creates a product that has economic value.

A few methods are carbon-neutral, meaning they add no new CO₂ to the environment. For example, when using CO₂ captured from the air or oceans and turning it into fuel or food, the carbon returns to the atmosphere, but the use of captured carbon avoids the need for new carbon from fossil fuels.

Other combinations, however, are harmful because they increase the amount of excess CO₂ in the environment. One of the most common underground storage methods – enhanced oil recovery – is a prime example.

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Underground carbon storage pros and cons

Projects for years have been capturing excess CO₂ and storing it underground in natural structures of porous rock, such as deep saline reservoirs, basalt or depleted oil or gas wells. This is called carbon capture and sequestration (CCS). If done right, geologic storage can durably remove large amounts of CO₂ from the atmosphere.

When the CO₂ is captured from air, water or biomass, this creates a carbon-negative process – less carbon is in the air afterward. However, if the CO₂ instead comes from new fossil fuel emissions, such as from a coal- or gas-fired power plant, carbon neutrality isn’t possible. No carbon-capture technology works at 100% efficiency, and some CO₂ will always escape into the air.

Capturing CO₂ is also expensive. If there is no product to sell, underground storage can become a costly service ultimately covered by taxes or fees, similar to paying for trash disposal. READ MORE

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AGENDA FOR A PROGRESSIVE POLITICAL ECONOMY OF CARBON REMOVAL (Institute for Responsible Carbon Removal)
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Is Large-Scale CDR Sustainable? (NORI)
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How carbon removal might scale up, and what could go wrong (Axios)
New report highlights crucial role of carbon dioxide removal in meeting 2050 climate goals (Canadian Biomass/B.C. Centre for Innovation and Clean Energy)

Excerpt from Institute for Responsible Carbon Removal: A first group of recommendations centers on(1) incentivizing carbon removal for the right reasons and at the right scale. We recommend:

• Rethinking how we incentivize and account for carbon removal to ensure that it does not delay emissions reductions;

• Transparently linking removals to what is truly ‘hard-to-abate’, as defined via participatory processes; and

• Producing bottom-up, interdisciplinary, inclusively developed estimates of carbon removal’s full potential scale.

A second group of recommendations focuses on (2) moving beyond both markets and private ownership as models for deploying carbon removal. We recommend:

• Rejecting offset models for carbon removal;

• Funding and conducting carbon removal via strategic, government-led industrial policy;

• Developing and incentivizing collective ownership models for carbon removal; and

• Treating intellectual property as a public good and supporting technology sharing. READ MORE

Excerpt from NORI:

Two recent journal publications point to potential risks associated with large-scale carbon dioxide removal (CDR). Is 10 gigatons annually a realistic and sustainable target? Should we aim for 1 gigaton, or could 28 be feasible? What land use and energy limitations are inherent in large-scale CDR, and what policy measures could ensure a just and scientifically rigorous implementation of this emerging technology?

In this episode, our Policy Panel discusses both the potential pitfalls and the potential necessity of large-scale carbon removal, as humanity continues to emit over 40 gigatons of CO2 annually (and counting).

A must-listen for those who question the viability of CDR as well as those who believe in the "gigatons or bust" approach.

On This Episode

Wil Burns

Holly Jean Buck

Radhika Moolgavkar

Resources

Science paper Environmental Science & Technology paperHolly's book Ending Fossil Fuels READ MORE/LISTEN