07/18/2013
Improving Estimates of Soil Organic Carbon Stored in Permafrost
Summary
Recent research has revealed that the amount of soil organic carbon (SOC) stored in the northern circumpolar permafrost region is far larger than earlier estimates, calling attention to the potential vulnerability of this carbon for release to the atmosphere. Even so, these new estimates of the quantity, decomposability, and combustibility of permafrost-region SOC stocks are poorly constrained, contributing to large uncertainties in model predictions of carbon–climate feedbacks under future warming. Two workshops held at Argonne National Laboratory during 2011 and 2012 led to a synthesis of the current differences between empirical and model estimates of the size and distribution of permafrost-region SOC stocks, and research needs to reduce this discrepancy were identified. Five research challenges for improving empirical assessments of the distribution and potential mineralization of SOC stocks in the northern permafrost region were highlighted. These include (1) improving the number and robustness of observations, (2) predicting the spatial and vertical distributions of SOC stocks, (3) characterizing existing carbon forms to better predict their fate, (4) using improved observation-based SOC estimates to inform model development, and (5) quantifying uncertainties in observations and predictions. These challenges are interlinked and suggest opportunities to organize, prioritize, and coordinate future research efforts to better understand and predict the impacts of permafrost SOC.
References
Mishra, U., J. D. Jastrow, R. Matamala, G. Hugelius, C. D. Koven, J. W. Harden, C. L. Ping, G. J. Michaelson, Z. Fan, R. M. Miller, A. D. McGuire, C. Tarnocai, P. Kuhry, W. J. Riley, K. Schaefer, E. A. G. Schuur, M. T. Jorgenson, and L. D. Hinzman. 2013. “Empirical Estimates to Reduce Modeling Uncertainties of Soil Organic Carbon in Permafrost Regions: A Review of Recent Progress and Remaining Challenges,” Environmental Research Letters 8, 035020. DOI:10.1088/1748-9326/8/3/035020.