Climate and environmental change in river deltas globally: expected impacts, resilience, and adaptation

A large part of the world’s population lives in coastal areas, and even though river deltas only contribute to 5% of the global land mass, over 500 million people live in these areas, where major rivers reach the ocean. Deltas have numerous advantages for societal development, such as a flat topography, available fresh and salt water resources, good transportation via waterways and the nearby coast, fertile soils for agriculture, and usually also a rich biodiversity and recreational value through, for example, wetland ecosystems, coastal forests, and beaches. However, at the same time, river deltas of the world belong to the most endangered ecosystems with respect to societal, environmental and climate change – the latter especially manifested through sea level rise (SLR). In this chapter we present the most common environmental impacts of society’s economic development expressed via agricultural intensification, increasing urban sprawl, industrial activity, and infrastructure expansion in deltas, as well as the climate change and SLR related challenges that threaten delta development in many countries. We discuss means of mitigation and adaptation towards these negative impacts, which can be of educational, ecological, technological and political nature, and depict how delta populations with differing resilience address the challenges induced by environmental and climate change. We use the Mekong Delta in Vietnam as a case study by addressing the threats and possible adaptation options of this region