Coastal Risk Index to help protect vulnerable coastal communities

The CRI, an open source platform, assesses coastal risks and promotes nature-based solutions. Mangroves, coral reefs and wetlands provide ecosystem services to vulnerable coastal communities facing increasing risks due to climate change and sea-level rise.

The Index is part of an Ocean Risk and Resilience Action Alliance (ORRAA) project that involves IHE Delft, AXA XL and the University of California – Santa Cruz. It combines several large datasets to make the information easily accessible and to decision makers, policy makers, and other stakeholders so that they can make informed decisions.

IHE Delft’s Johan Reyns, Lecturer/Researcher in Coastal Morphodynamics, and Rosh Ranasinghe, Professor of Climate Change Impacts & Coastal Risk, together with external collaborators, undertook this challenging global assessment of the coastal flood impact reduction afforded by mangroves and coral reefs. Their computations cover both the present situation and a future emissions scenarios. The CRI outcomes underscore the crucial role that nature-based solutions could play to prevent or mitigate coastal flood damage.

“We hope that by clearly showing how climate-change-related coastal flooding can impact coastal communities and assets, and the important role that coastal ecosystems can play in mitigating those risks, the CRI will spark urgent action to better protect the planet,” Ranasinghe said. “The CRI combines several large datasets with numerical modelling to make the information easily accessible and understandable for decision makers and policy makers all over the world. Now we need them to take action.”

The ecosystem services provided by natural resources such as mangroves, coral reefs and wetlands support livelihoods and reduce economic risks. About 40 percent of the global population live in coastal areas, and two-thirds of the world’s publicly listed companies depend on a healthy ocean.  If no action is taken to mitigate the threat of flooding, the blue economy could see 8.4 trillion USD in losses in next 15 years.

The stakes are high. By showcasing the social and economic risks in real time, the creators of the Index hope to spark action to mitigate the threat to lives and livelihoods. By understanding the coastal hazards their communities are exposed to, and highlighting the essential role of natural defences like mangroves, decision-makers can develop more robust risk reduction strategies to safeguard and restore natural resources around the world.