From Watts Up With That?

By Jonathan Lesser

Most policies designed to reduce carbon emissions have focused on reducing reliance on fossil fuels, primarily through state and federal mandates, including requirements to increase reliance on wind and solar power, replace oil and gas furnaces and water heaters with electric heat pumps, and force automobile manufacturers to sell electric vehicles that most consumers don’t want. These mandate “sticks” have all been accompanied by subsidy “carrots,” paid for by taxpayers and ratepayers.

Many of the subsidies were increased under the Inflation Reduction Act of 2022. But the largest subsidy of all was entirely new: A payment of up to $180 per metric ton to capture carbon dioxide, literally out of thin air, and thereby mitigate climate change by reducing the atmospheric concentration of CO₂. The carbon dioxide captured by Direct Air Capture (DAC) could then be reused, for example, in enhanced oil recovery, or permanently buried underground.

A U.S. Department of Energy (DOE) report issued at the end of the Biden Administration estimated that the U.S. would need to remove between 100 million metric tons and 2 billion metric tons of carbon dioxide using Direct Air Capture technology to address climate change.

In essence, DAC involves large fans that draw outdoor air through liquid or solid media that capture CO2, remove it via chemical processes, and then compress it for transport and either use or sequester it. There are several dozen small DAC facilities in operation, mostly in Europe. The goal of DAC advocates is to build large-scale facilities, each capable of extracting 1 million metric tons of CO₂ each year. Two companies, ClimeWorks and Carbon Engineering, have commercialized different technologies for DAC. Currently, the only large-scale facility is under construction by Occidental Petroleum in the Permian Basin of Texas. That facility, called Stratos, is designed to capture up to 500,000 metric tons of CO₂ annually, which will be injected into the company’s oil wells to enhance crude oil production.

But as I explain in my new report, these technologies, and all potential DAC technologies, have an Achilles Heel: The laws of thermodynamics. Regardless of the technology employed, extracting CO₂ directly from the atmosphere is inherently energy-intensive.

Because burning fossil fuels to power DAC facilities would reduce, or even negate, the carbon-reduction goal, DAC technologies have focused on using electricity generated from zero-emissions sources.

For example, the theoretical minimum of energy needed to meet a one billion metric ton objective would require the equivalent of 10% of all electricity generated in the U.S. in 2024. The practical energy required would be at least 30%, as no technology can be 100% efficient. Producing that much electricity would require building hundreds of new nuclear plants. If wind and solar power were relied on, it would require an area larger than the state of Florida, and hundreds of thousands of megawatts of battery storage facilities to compensate for wind’s and solar’s inherent intermittency. The cost to build the required generating capacity alone would be trillions of dollars. Building additional transmission lines and the DAC facilities themselves would cost hundreds of billions of dollars more. In total, the cost is likely to be over $400 per metric ton of CO₂ removed. That’s far higher than even the most recent estimates of the social cost of carbon, which supposedly measures the damages to the climate from each additional ton of CO₂ emitted.

Despite the huge energy requirements, the impacts on atmospheric CO₂ concentrations and global temperatures would be minuscule. The current atmospheric CO₂ concentration is approximately 425 parts per million (ppm).

Removing one billion metric tons of CO₂ would reduce the concentration by only 1/10 of 1 ppm and based on the Intergovernmental Panel on Climate Change’s climate sensitivity estimates, by 0.003 °C.

That’s about 40 times less than the assumed margin of error in measuring global temperatures. Even if billions of metric tons of CO₂ were captured and sequestered annually, the impact on world temperatures by the year 2100 would be too small to have any noticeable impact on the climate.

Finally, storing CO₂ underground poses environmental and health risks because it could escape, as in Cameroon in the 1980s, when Lake Nyos “burped” several hundred thousand tons of CO₂, leading to the deaths of 1,700 people and thousands of cattle. It would be unreasonable to assume that, after sequestering billions of tonnes of CO₂ underground, similar events could not take place.

Taken together, these physical, economic, and environmental realities mean that DAC is a technology whose time will never come.

Jonathan Lesser is a Senior Fellow with the National Center for Energy Analytics. His report, “A Cost-Benefit Analysis of Using Direct Air Capture to Remove Atmospheric Carbon,” was just published.

This article was originally published by RealClearEnergy and made available via RealClearWire.