Enhancing soil carbon storage for carbon remediation: potential contributions and constraints by microbes

Terrestrial carbon sequestration represents an important option for partially mitigating anthropogenic CO2 emissions. Evidence suggests that terrestrial ecosystems can be managed for carbon sequestration, but it is not certain to what extent the microbes within them can be manipulated. Challenges include identifying which specific microbes and mechanisms contribute to sequestered carbon; understanding how microbial communities respond over large spatial and long temporal scales to crucial environmental variables; and developing management strategies suitable for large spatial and long temporal scales. The growing recognition that microbes produce proteins that limit organic matter degradation suggests targets for basic research. Directly manipulating microbes to sequester CO2 through other processes such as mineral formation offers intriguing alternatives that merit further attention, but at present the prospects for practical implementation appear remote.