Poster's note : appears to imply that rather more care needs to be taken with soil, and that soil CDR will be significantly more challenging than is sometimes argued.
http://science.sciencemag.org/lookup/doi/10.1126/science.aad4273 Radiocarbon constraints imply reduced carbon uptake by soils during the 21st century Yujie He1,*, Susan E. Trumbore2, Margaret S. Torn3,Jennifer W. Harden4,5, Lydia J. S. Vaughn3, Steven D. Allison1,6, James T. Randerson1 Email: [email protected] Science 23 Sep 2016: Vol. 353, Issue 6306, pp. 1419-1424 DOI: 10.1126/science.aad4273 Abstract Soil is the largest terrestrial carbon reservoir and may influence the sign and magnitude of carbon cycle–climate feedbacks. Many Earth system models (ESMs) estimate a significant soil carbon sink by 2100, yet the underlying carbon dynamics determining this response have not been systematically tested against observations. We used14C data from 157 globally distributed soil profiles sampled to 1-meter depth to show that ESMs underestimated the mean age of soil carbon by a factor of more than six (430 ± 50 years versus 3100 ± 1800 years). Consequently, ESMs overestimated the carbon sequestration potential of soils by a factor of nearly two (40 ± 27%). These inconsistencies suggest that ESMs must better represent carbon stabilization processes and the turnover time of slow and passive reservoirs when simulating future atmospheric carbon dioxide dynamics -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
