Blue carbon at risk: Mangrove sediment stocks could drop 30% by 2100 without managed retreat
earth.comA new global study published in Regional Studies in Marine Science projects that mangrove sediment carbon stocks could fall 15 to 30 percent by 2100 if coastal development blocks their landward migration. The research, led by Agradeep Mohanta, shows that rising seas combined with seawalls and roads create coastal squeeze, trapping wetlands and exposing ancient carbon to oxidation. Indonesia faces the highest emissions risk, while Mexico and Australia have pathways for carbon gains. The study also found that managed retreat allowing wetlands to move inland could flip the outcome to net carbon gains globally. Mangroves are expanding into higher latitudes as freeze events decline, changing the carbon storage profile of coastlines. Salt marsh and seagrass datasets remain too sparse for similar national projections, highlighting a gap in modeling tools for planners.