Harnessing nature to help people adapt to climate change: Identifying global high-priority areas for coastal ecosystem-based adaptation

Background/Question/Methods

Ecosystem-based adaptation (EbA) – targeted ecosystem management, conservation, and restoration that will help people adapt to climate change  – has the potential to both protect biodiversity and reduce the impacts of climate change.  For example, restoring and/or conserving mangroves protects coastal communities from tropical storms (because mangroves dissipate storm surge energy) and also protects the associated biodiversity of mangrove ecosystems. As funding for adaptation is limited, opportunities for EbA need to be compared directly to hard-engineering approaches (e.g. sea walls) for feasibility, benefit/cost ratio, and resilience under uncertainty.  However, opportunities for EbA to provide adaptation benefits have rarely been examined in a spatially explicit manner.  We identified high-priority areas for coastal EbA both globally and regionally. We defined high-priority areas for EbA as those that have intact and potentially restorable mangroves and/or coral reefs.  First, we identified where people are most vulnerable to climate change by creating a composite map of where exposure to climate change is highest, sensitivity of communities is greatest, and adaptive capacity is lowest.  We then overlaid the vulnerability map with the current extent of mangroves and coral reefs and maps of threats to both ecosystems to visualize locations with the highest potential to benefit from EbA. 

Results/Conclusions

When the data are viewed globally, coastal areas in Southeast Asia such as Myanmar, Vietnam, Indonesia, and the Philippines both are particularly vulnerable to climate change impacts and have intact and potentially restorable coastal ecosystems that could help protect them from climate-induced sea-level rise and tropical storms. Bangladesh, India, Madagascar, Honduras, Cuba, and Haiti also have particularly vulnerable coastal populations where coastal ecosystems can be managed and/or protected and/or restored to ensure adaptation benefits continue to be delivered as climate change proceeds.  We also identified specific sub-regions in each of The World Bank’s global regions for high EbA prioritization.  Our methodology is a beneficial starting point for adaptation planners to visualize and identify places where further examination could help pinpoint areas for strategic investment in EbA and gives an alternative to the drawbacks of the widely used hard engineering adaptation strategies.  This is an important advancement because EbA has great potential to address adaptation needs of people, while simultaneously protecting ecosystems into the future.