Shallow Geologic Storage of Carbon to Remove Atmospheric CO2 and Reduce Flood Risk

Environ Sci Technol. 2023 Jun 13;57(23):8536-8547. doi: 10.1021/acs.est.3c00600. Epub 2023 Jun 1.

Abstract

Geologic carbon storage currently implies that CO2 is injected into reservoirs more than 1 km deep, but this concept of geologic storage can be expanded to include the injection of solid, carbon-bearing particles into geologic formations that are one to two orders of magnitude shallower than conventional storage reservoirs. Wood is half carbon, available in large quantities at a modest cost, and can be milled into particles and injected as a slurry. We demonstrate the feasibility of shallow geologic storage of carbon by a field experiment, and the injection process also raises the ground surface. The resulting CO2 storage and ground uplift rates upscale to a technique that could contribute to the mitigation of climate change by storing carbon as well as helping to adapt to flooding risks by elevating the ground surface above flood levels. A life-cycle assessment indicates that CO2 emissions caused by shallow geologic storage of carbon are a small fraction of the injected carbon.

Keywords: carbon removal; climate change adaptation; climate change mitigation; flood protection; geologic storage; global warming; negative emission technology; sea level rise.

MeSH terms

  • Carbon Dioxide*
  • Carbon*
  • Climate Change
  • Floods

Substances

  • Carbon Dioxide
  • Carbon