Direct Air Capture: Assessing Impacts to Enable Responsible Scaling


Analysis of commercially ready DAC systems indicates that on-site impacts are expected to be similar to those of industrial facilities of a comparable size, but with much lower GHGs and other air pollutant emissions. Solvent DAC plants would release some aerosolized chemical solvent but at much lower levels than is regulated; DAC plants powered with natural gas would also produce small amounts of CO2 and nitrogen oxides (NOx) emissions, much lower than conventional natural gas plants. Most emissions related to DAC would happen off-site, related to production of materials needed to build and run the plant. DAC at a 0.5 GtCO2/year scale is expected to have only incremental impacts on production of materials like cement and steel but would have substantial energy requirements and require scale-up of sorbent production. Because these impacts differ by project and will change as the technology improves, environmental and social impact assessments will be needed on a project-by-project basis.

This analysis offers a starting place to inform decision-makers in advancing an equitable and responsible scale-up of DAC to meet the expected carbon removal need. The federal government, states, and municipalities, and the private sector will need to collaboratively identify suitable locations for DAC and configurations that are best for each location, along with enacting policies that integrate equity considerations into DAC development. To enable an equitable DAC scale-up, stakeholders should play an early and central role in decision-making guiding DAC development to maximize benefits and minimize harm to communities hosting DAC plants. Early investments in community engagement and equitable policies and programs require time and resources, but are vital for the long-term success and equity of the DAC industry. DAC has the potential to become either an important technology to address climate change or a technology that does not gain widespread use due to lack of public acceptance. Careful development of DAC with environmental and social safeguards will enable effective and responsible DAC scale-up.

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