Reconstructing “background” Rates of sea-level rise as a tool for forecasting coastal wetland loss, Mississippi Delta



The Mississippi Delta is one of the most vulnerable coastal regions in the world, with rapidly deteriorating wetlands and an increasing threat for the city of New Orleans due to accelerated relative sea-level (RSL) rise. Rational coastal forecasting and policy-making for this area requires a detailed understanding of the temporal and spatial dimensions of RSL change. However, considerable controversy currently exists about the nature of Holocene RSL rise along the Gulf Coast. We have collected new, high-resolution RSL data from the eastern part of the Mississippi Delta that show that this area experienced smooth and continuous RSL rise that gradually decreased during the Holocene, consistent with numerous observations worldwide. Here, we demonstrate the potential of such data for quantifying natural “background” rates of RSL rise that should be taken into account in coastal forecasting of such threatened environments.