Mangroves support the global ecosystem and serve as blue carbon reservoirs. However, they are facing threats from climate change phenomena, such as sea-level rise, and human activities, such as deforestation, erosion, pollution, reservoir construction and coastal development. Few studies have examined the trends in carbon, nutrients and pollutants in mangrove systems over a timescale of 100–150 years due to climate change and human activities. The objectives of this study are (i) to determine the effects of human activities and climate change on the abilities of mangroves to serve as carbon and nutrient sinks, and (ii) to assess the potential of these mangroves facing deterioration over the past century. Sediment cores will be collected from the coastal fringes of mangroves across East and Southeast Asia for evaluation of total organic carbon, total nitrogen, total phosphorus and inorganic and organic pollutants. Trends in these parameters from past to present will indicate whether the efficiency of these mangroves to accumulate carbon and nutrients has changed. The sediment accumulation rates of these mangroves will be compared with the rates of sea-level rise to determine whether the mangroves are being submerged. The degree of mangrove deterioration will be investigated by determining their areal changes using satellite imagery. The results of this study will provide important information for policymakers to maintain the sustainability of these fragile ecosystems.