Search

The atmospheric concentration of CO2 is steadily increasing and causing climate change. To achieve the Paris 1.5 or 2°C target, negative emission technologies must be deployed in addition to reducing carbon emissions. The ocean is a large carbon sink but the potential of marine primary producers to contribute to carbon neutrality remains unclear.Here we review the alterations to carbon capture and sequestration of marine primary producers (including traditional 'blue carbon' plants, microalgae and macroalgae) in the Anthropocene, and, for the first time, assess and compare the potential of various marine primary producers to carbon neutrality and climate change mitigation via biogeoengineering approaches.The contributions of marine primary producers to carbon sequestration have been decreasing in the Anthropocene due to the decrease in biomass driven by direct anthropogenic activities and climate change. The potential of blue carbon plants (mangroves, saltmarshes and seagrasses) is limited by the available areas for their revegetation. Microalgae appear to have a large potential due to their ubiquity but how to enhance their carbon sequestration efficiency is very complex and uncertain. On the other hand, macroalgae can play an essential role in mitigating climate change through extensive offshore cultivation due to higher carbon sequestration capacity and substantial available areas. This approach seems both technically and economically feasible due to the development of offshore aquaculture and a well‐established market for macroalgal products.Synthesis and applications. This paper provides new insights and suggests promising directions for utilizing marine primary producers to achieve the Paris temperature target. We propose that macroalgae cultivation can play an essential role in attaining carbon neutrality and climate change mitigation, although its ecological impacts need to be assessed further. [ABSTRACT FROM AUTHOR]

The continued rise in anthropogenic carbon dioxide (CO2) emissions and increase in atmospheric CO2 concentration has led to calls from experts, including the Intergovernmental Panel on Climate Change that has estimated that global warming needs to be limited to 1.5 °C above preindustrial levels to avoid the worst effects of climate change, and that carbon neutrality would need to be achieved globally by 2050 to meet this target. Achieving carbon neutrality by mid‐century will rely on successful implementation and widespread adoption of technologies for reducing emissions from large point sources of CO2, direct CO2 capture from the air, as well as storage and utilization technologies that would convert CO2 to a form that would ensure safety and permanency of storage. In this paper, engineering solutions for CO2 capture, utilization, and storage are reviewed with a focus on technology readiness level, and cost. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]