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New analysis demonstrates that restoring mangroves and coral reefs can be a cost-effective solution for reducing coastal flooding in more than 20 Caribbean countries.

The study, published on May 28 in the journal ecosystem servicehave used methods from the risk and insurance industry to provide rigorous evaluations of these natural defenses and show that they can deliver a positive return on investment, with the benefits of reduced flood damage exceeding catering costs.

The findings point to new opportunities to support restoration efforts with funds from sources that support risk mitigation, climate adaptation and disaster recovery, including the U.S. Federal Emergency Management Agency (FEMA ).

“We identify a number of funding sources that have traditionally supported man-made ‘grey infrastructure,’ such as concrete seawalls, that could be applied to nature-based solutions,” said lead author Michael Beck. , research professor at the Institute of Marine Sciences at UC Santa Cruz who holds the AXA Chair in Coastal Resilience.

Coastal ecosystems such as coral reefs and mangroves act as natural barriers against waves and storm surges and reduce flood damage to people and property. In many places, however, the degradation of reefs and coastal wetlands has reduced their natural ability to protect coastlines from flooding and erosion. Effective strategies exist to restore these critical ecosystems, but funding for restoration projects can be difficult to find.

Beck noted that global spending on disaster recovery is more than 100 times greater than spending on conservation. “Recovery funding will increase as climate change increases impacts from storms, and environmental funding will likely decline as national budgets are strained by natural disasters,” he said.

The study highlights opportunities to align conservation, flood risk reduction and climate adaptation to reduce storm risk. “Funding for man-made infrastructure such as seawalls can be redirected to natural defenses, which provide multiple benefits beyond coastal protection,” Beck said.

Study results for ROI are robust to variations in discount rates and the timing of flood protection benefits, he added. “It may sound esoteric, but it can be essential to securing funding for restoration projects from sources like FEMA,” he said.

The researchers identified specific sites where there could be significant returns on investment for the restoration of coral reefs and mangroves in the Caribbean.

In addition to Beck, the paper’s co-authors include Nadine Heck, Siddharth Narayan, Pelayo Menéndez, Borja G. Reguero, and Stephan Bitterwolf at UC Santa Cruz; Saul Torres-Ortega and Iñigo J. Losada from the University of Cantabria, Spain; Glenn-Marie Lange at the World Bank; Kerstin Pfliegner at ERM, Germany; and Valerie Pietsch McNulty of the Nature Conservancy.

This work was supported in part by the Kingfisher Foundation, the World Bank, AXA XL, the AXA Research Fund, The Nature Conservancy and the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety.