Grand Challenges in Microbe-Driven Marine Carbon Cycling Research.

Keywords: biological carbon pump; blue carbon; chemolithoautotroph; climate change; climate remediation; greenhouse gases; marine carbon cycle; microbial carbon pump EN biological carbon pump blue carbon chemolithoautotroph climate change climate remediation greenhouse gases marine carbon cycle microbial carbon pump 1 6 6 06/26/20 20200623 NES 200623 Given the climate change crisis, it is urgent to reduce anthropogenic CO SB 2 sb emissions and explore climate geoengineering opportunities. Although the ocean's total primary production is very high (up to 50 Gt C/year), only a small fraction (<10%) is transported to the deep ocean I via i the BCP and even a smaller fraction (<1%) is sequestered for millennia (Henson et al., [45]; Bach et al., [7]; Fender et al., [36]; Giering et al., [39]). Research on fundamental processes and mechanisms of the BCP and MCP under varying oceanographic and climatic conditions is urgently needed, with a particular focus on integrating the major biogeochemical cycles and the ocean's biological, chemical, and physical processes for a better understanding of the marine carbon cycle and its response to climate change (Lucas et al., [64]; Hwang et al., [49]; Bif et al., [11]; Igarza et al., [50]; Quigley et al., [79]; Romera-Castillo et al., [87]). Advances in upcoming marine carbon cycling research may also help overcome the uncertainty and difficulty in developing environmental-friendly ocean geoengineering techniques for climate change mitigation, the success of which may as well require interdisciplinary collaborations, strategic planning, technique innovations, and systematic investigations including both BCP and MCP for integrated ocean carbon sequestration enhancement (Polimene et al., [78]; Emerson, [33]; Sloyan et al., [94]; Sogin et al., [95]; Zhang et al., [114]). [Extracted from the article]