Three critical problems to consider for marine carbon dioxide removal

Bach et al., (2024)


Gigatonne-scale carbon dioxide removal (CDR) will become essential to keep global warming below 2 degrees. In this paper, we discuss 3 challenges for marine CDR (mCDR): additionality, predictability, and governability. Additionality is perhaps the most important metric defining the success of a mCDR method as it describes its "net climatic benefit". We explain/discuss additionality in the mCDR context. Crucial aspects are: Additionality needs to be integrated over longer timescales, not only carbon but also radiative forcing needs to be considered more comprehensively, and the challenge of constraining it differs among mCDR methods. We further argue that CDR will be more predictable for less complex mCDR methods. Due to this, less complex methods will also be easier to govern as they have less potential to lead to unpredictable outcomes.

This paper is collected in the SOLAS Special Feature "Boundary Shift: The Air-Sea Interface in a Changing Climate".

Reference: Bach, L.T., Vaughan, N.E., Law, C.S., & Williamson, P. (2024).Implementation of marine CO2 removal for climate mitigation: The challenges of additionality, predictability, and governability. Elem. Sci. Anth.,  12(1): 00034.