With more than $300 billion paid out by insurers for coastal storm damage in just the past 10 years, losses from natural disasters are reaching all-time highs, according to The Nature Conservancy.
As coastal communities seek to maximize the cost-effectiveness of their infrastructure solutions, The World Bank’s Wealth Accounting and Valuation of Ecosystem Services (WAVES) global partnership and a team of cross-sector researchers led by The Nature Conservancy have released a new report to more effectively value nature-based solutions for reducing coastal risks.
The report, “Managing Coasts with Natural Solutions: Guidelines for Measuring and Valuing the Coastal Protection Services of Mangroves and Coral Reefs”, outlines a more precise path to measuring the protective services of mangroves and coral reefs alongside other traditional infrastructure options, such as breakwaters and seawalls.
The Guidelines draw on common valuation approaches used by insurance and engineering industries and present ways to measure nature-based solutions in a manner consistent with national economic standards.
“By bringing together ecologists, economists and engineers, we have advanced a rigorous approach for valuing the powerful benefits that reefs and mangroves provide for protecting people and property,” said Michael Beck, Lead Marine Scientist at The Nature Conservancy.
“By showing how we can make ‘apples-to-apples’ comparisons of the value of natural and artificial defenses—we might be at a tipping point in adoption of crucial nature-based solutions.”
The Guideline provides a comprehensive global review of the use of mangroves and reefs for coastal defense in policy and practice. Mangroves have the capacity to reduce wave height from 13 to 66 percent over 100-meter-wide belt, and 50 to a full 100 percent over a 500-meter-wide mangrove belt.
Coral reefs protect against erosion and flooding by reducing wave energy up to 97 percent and by supplying and trapping sediment on adjacent beaches.
The Guidelines also feature examples of nature-based solutions currently being integrated into major policy decisions in countries around the world including:
- Vietnam: 9,000 hectares of reforested mangroves demonstrated cost benefit ratios from 3:1 in some communities to as high as 28:1 in other locations;
- The Philippines: The Government of the Philippines pledged US$8 million for a cash-for-work program to restore mangroves and beach forests along the hardest hit coastlines after Typhoon Haiyan in 2013;
- The Caribbean Catastrophic Risk Insurance Facility (CCRIF) found that in seven out of eight countries examined, reef and mangrove restoration was one of the most cost effective approaches to coastal risk reduction and adaptation.