Ocean-based Carbon Dioxide Removal

With each passing year, the need for net-negative carbon dioxide emissions increases to mitigate the worst effects of climate change. Simply curtailing emissions is no longer enough – CO2 must be removed from the atmosphere to meet international climate goals (IPCC AR6 2022). This is a gargantuan challenge in speed, scope, and scale, which will require extensive interdisciplinary collaboration. It is also a uniquely important opportunity for geobiology and biogeochemists in general to provide insight and expertise to guide and create carbon sequestration techniques and strategies to hopefully obtain the best outcomes, or at least avoid worst case scenarios.

Our group at UCSB is utilizing our expertise in organic matter breakdown and storage in geologic reservoirs to assess the effectiveness of one marine carbon dioxide removal (mCDR) technique: biomass burial. We want to know if biomass carbon (i.e. plants) can be added to anoxic basins as a long term carbon sequestration technique. This takes advantage of natural photosynthesis to fix carbon, as well as prevents the release of that carbon back to the atmosphere as CO2 upon degradation or burning of plant waste products. This research is guided by analogy the apparent increase in organic matter preservation potential in ancient anoxic basins or coal beds in geologic time. We are working to understand biomass breakdown rates and modes of stability for various materials in anoxic basins, as well as determine the best ways (or even potential ways) to monitor the effectiveness of carbon sequestration as a whole over time. Further, we are exploring the ways in which carbon sequestration interventions (in this case plant matter added to anoxic marine sediment) may impact local biogeochemistry and microbial community dynamics. Overall, we hope to provide insight into how to best utilize our global resources to mitigate as much harm as possible while providing effective biomass burial as part of a working portfolio of mCDR techniques.

Data is ongoing, but see our current works on this strategy below!

Biomass storage potential in anoxic basins: https://doi.org/10.1029/2023AV000950

Preprint: Observational strategies for biomass burial mCDR: 10.22541/essoar.172711284.45251635/v1