Microbial carbon pump for climate
A study involving Hereon shows how the microbial carbon pump influences climate change
Climate change is fundamentally influenced by the sequestration of carbon in the ocean. The dissolved organic carbon is produced and metabolized by microbial and ecological processes – the phenomenon is known as the microbial carbon pump. Researchers with the participation of the Helmholtz-Zentrum Hereon have discovered that this pump has far more leverage: This pump has far more leverage than hitherto assumed. They have now published their years of accumulated expertise in the journal Nature Review Microbiology.
The ocean has always been a regulator of climate change. The researchers‘ new findings: Firstly, the microbial carbon pump (MCP) is probably a far more significant lever for climate change than hithrto assumed. Considering global carbon reservoirs, the oceans hold over 50 times moreCO2 than the atmosphere. This means that small changes in the ocean carbon reservoir are barely noticeable but can have dramatic effects in the atmosphere. Secondly, bacteria and viruses play a major role in the deep ocean in terms of the reservoir of refractory, i.e. stable, dissolved organic carbon (RDOC). And thirdly, aided by modeling, the processes in deeper ocean waters could be better understood. The researchers also postulate that these processes play a greater role in coastal regions than in the high seas.
The insights into the molecular structure of dissolved organic carbon are among the major advances in chemical oceanography and thus the study, which were made possible by high-resolution analytical methods. „This study represents more than ten years of work. It is another piece of the puzzle in understanding the carbon cycle,“ says Prof Helmuth Thomas, Director of the Hereon Institute of Carbon Cycles, who supported first author Dr Jiao Nianzhi from Xiamen University in China with around 30 researchers. „However, there are still questions regarding the understanding of the mechanisms and their interactions. To answer these, observations in the real world, experimental and model studies and simulations with digital twins are needed,“ Thomas continues. (Source: Hereon Press Release)
Read the complete Hereon Press Release:
==> Pump for climate
Jiao, N., Luo, T., Chen, Q., Zhao, Z., Xiao, X., Liu, J., Jian, Z., Xie, S., Thomas, H., Herndl, G.J., Benner, R., Gonsior, M., Chen, F., Cai, W.-J., & Robinson, C. (2024): The microbial carbon pump and climate change. Nat Rev Microbiol (2024), doi:10.1038/s41579-024-01018-0
Abstract:
The ocean has been a regulator of climate change throughout the history of Earth. One key mechanism is the mediation of the carbon reservoir by refractory dissolved organic carbon (RDOC), which can either be stored in the water column for centuries or released back into the atmosphere as CO2 depending on the conditions. The RDOC is produced through a myriad of microbial metabolic and ecological processes known as the microbial carbon pump (MCP). Here, we review recent research advances in processes related to the MCP, including the distribution patterns and molecular composition of RDOC, links between the complexity of RDOC compounds and microbial diversity, MCP-driven carbon cycles across time and space, and responses of the MCP to a changing climate. We identify knowledge gaps and future research directions in the role of the MCP, particularly as a key component in integrated approaches combining the mechanisms of the biological and abiotic carbon pumps for ocean negative carbon emissions.
