Published In


Document Type


Publication Date



Ecosystem services, Environmental health, Global environmental change -- Social aspects, Climatic changes -- Mitigation, Environmental refugees


This paper examines the history and current status of ecosystem services in low-lying coastal areas (LLCAs), their potential changes because of wider environmental and social shifts, and the potential impacts of these changes on human migration. We synthesised information from a number of sources on the status and value of ecosystem services in LLCAs, including information about key ecosystems that are likely to be particularly vulnerable to environmental change. We created maps of ecosystem and human population changes in LLCAs and then estimated changes in ecosystem services. Estimating the impacts of these potential changes depends on the future scenario one assumes. For our analysis four scenarios were developed for future ecosystem and ecosystem services conditions in 2060, based on the four SRES (Special Report on Emissions Scenarios) scenarios with additional reference to the Millennium Ecosystem Assessment and the Great Transition Initiative scenarios. The two axes of the SRES scenarios are global vs. regional and material economy vs. environment foci. This allowed an assessment of the plausible range of future uncertainty about ecosystem services in LLCAs and the potential for changes in ecosystem services to drive human migration. Major findings include: ? Coastal ecosystems are among the most productive on the planet. They provide more than 70% of total global ecosystem services. ? At the same time, these systems are the most threatened by climate change, human settlement and potential coastward migration. ? In the mid-1990s, approximately 25 million people were forced to leave their homelands owing to the inability to secure a livelihood as ecosystem services declined (Myers and Kent, 2009). ? In the coming decades, one estimate puts the number at 240?525 million people globally who may feel impelled to migrate because of loss of ecosystem services (Myers and Kent, 2009). ? Risk factors for coastal populations include over-exploitation of resources, including fisheries; destruction of mangroves, wetlands, and other natural infrastructure; increased storm activity; and reduced resilience to environmental perturbations. ? Coastward population migration is largest in the globalised scenarios because of increased ease of migration in a more globalised world. ? Coastal ecosystem services decline in the material economy-focused SRES scenarios but potentially increase in the environment-focused SRES scenarios, leading to higher overall quality of life. Policies should aim to preserve and restore coastal habitats. This leads to higher and more stable coastal ecosystem services and human quality of life, along with lower vulnerability to migration pressures. Additional research and integrated modelling are needed, however, to better understand the spatial dynamics of human migration and its dependence on ecosystem services. Such models could also help illuminate the transition pathways and policies necessary to achieve the preferred future scenarios.


© Crown copyright 2011. Review and associated publications may be found at

Persistent Identifier