Life cycle assessment of ocean-based carbon dioxide removal approaches: A systematic literature review
Mona H. Delval, Nils Thonemann, Patrik J. G. Henriksson, Samantha Eleanor Tanzer, Philipp Behrens
Abstract
As climate impacts worsen, novel technologies to draw down atmospheric carbon are gaining attention. One such approach is ocean-based carbon dioxide removal (OCDR). However, the potential environmental side-effects of large-scale OCDR deployment remain understudied. Here, we present a systematic literature review of the life cycle assessments (LCAs) of OCDR approaches. We find that current OCDR LCAs have a limited scope, often overlook environmental impacts beyond global warming, and that LCA as a method is currently limited in capturing aquatic impacts. We provide several recommendations for future work, such as using a functional unit of storing atmospheric carbon over a specified time horizon and in a specified medium, performing cradle-to-grave analysis, including more (marine) environmental impacts, and estimating uncertainties. We also emphasise the need to develop the LCA methodology further for better assessing marine environment impacts. • We found 20 LCAs on OCDR approaches and provide guidelines for future OCDR LCAs. • Environmental side-effects of deploying OCDR on a large scale are largely unknown. • Current LCA models cannot assess the full impacts of OCDR on marine environments. • Precautions are needed when drawing conclusions from results of LCAs on OCDR. • More work is needed to assess impacts occurring in the marine environment in LCA.