Uncertainty In Greenhouse Gas Emissions On Net Carbon Sequestration In Coastal and Freshwater Wetlands In The Mississippi River Delta.

The highly visible phenomenon of wetland loss in coastal Louisiana (LA) is examined through the prism of carbon accumulation, wetland loss and greenhouse gas (GHG) emissions. Carbon storage or sequestration in rapidly subsiding LA coastal marsh soils is based on vertical marsh accretion and areal change data. While coastal marshes sequester significant amount of carbon through vertical accretion, large amounts of carbon previously sequestration in the soil profile is lost through annual deterioration of these coastal marshes as well as through GHG emissions.  Efforts are underway in Louisiana to access the carbon credit market in order to provide significant funding for coastal restoration projects.   However, there is very large uncertainty on GHG emission rates related to both marsh type and temporal (daily and seasonal) effects.  Very little data currently exists which addresses this uncertainty which can significantly affect the carbon credit value of a particular wetland system.