Can carbon capture solve climate change?

Emissions from burning fossil fuels and agricultural production have pumped Earth’s atmosphere full of carbon dioxide (CO₂), warming the planet to dangerous levels.

There’s been much emphasis on reducing CO₂ output by switching to greener energy sources, like solar and wind. Scientists and entrepreneurs have also been increasingly interested in capturing the CO₂ in the atmosphere and storing it or putting it to use, a practice dubbed carbon capture or carbon removal.

At a recent Dornsife Dialogues event, experts convened to discuss the promises and problems of this carbon capture technology.

What is carbon removal?

Carbon dioxide removal takes many forms, from planting more trees to scrubbing CO₂ from the atmosphere and tucking it away underground.

Earth is already an expert in carbon removal. Trees are famous for their carbon capture prowess. Oceans are an even bigger ally: Wherever air meets sea, carbon is sucked into the water where it reacts with limestone rock on the ocean floor and converts it to the solid bicarbonate. This keeps excess carbon locked away, to the tune of 3 billion tons a year.

Unfortunately, Earth’s timeline can’t match human demand. “The problem is that Earth runs this process. It does this chemistry at its own pace, which is quite slow, whereas we’ve been putting CO₂ in the atmosphere very quickly over the last 100 years,” says William Berelson, Paxson H. Offield Professor in Coastal and Marine Systems and professor of Earth sciences, environmental studies and spatial sciences.

Berelson is hoping to boost the ocean’s carbon-absorbing power. He’s working on a carbon removal system that captures CO₂ as it’s produced by the shipping industry, mixes it with limestone, and then releases it back into the ocean as bicarbonate.

Would carbon capture technology just enable continued fossil fuel use?

Some critics argue that carbon removal may disincentivize ending reliance on fossil fuels.

Joe Árvai, Dana and David Dornsife Chair, Wrigley Institute director and professor of psychology, biological sciencesand environmental studies, says that we need to focus on both reduction and removal for several reasons. For one, not all emissions can be entirely erased through green energy. “Some industries, like agriculture, are going to be really, really hard in the near term to fully decarbonize,” he says.

Plus, there’s the problem of legacy emissions. Even if

CO₂ production suddenly stopped, the atmosphere is already packed with too much, which will continue to contribute to climate change unless its removed.

Find a transcript of this audio here under the transcript tab.

Who is going to pay for this technology?

Carbon removal technology doesn’t make a particularly desirable product. There isn’t much of a market currently for carbon, although scientists think that could one day change. Thus, paying for the installation of a carbon removal plant can be a challenge.

Árvai says that policy could help incentivize change. A government might require that companies that produce emissions must also remove them, or risk fines and a suspension of operations. This could create market incentives to drive down the coast of carbon removal and would also essentially act as a tax on emissions.

“If I have to pay to take the CO₂ out, and it costs $400 a ton to do that, I’m going to do everything in my power not to emit in the first place,” says Arvai.