Adapting to Climate Change: Assessing the World Bank Group ...

APPENDIX HADDITIONAL EVIDENCEDrylands are defined (FAO/IIASA 2010) as having a growing period lengthof 60 to 180 days.Accessibility map, created by Siobhan Murray. Areas were classified asremote if they were more than 5 hours travel time from the nearest city of100,000 or moreH2: Economic Value of Mangrove Coastal Protection BenefitsIEG examined 16 completed World Bank projects approved since 1990 of which 8identified coastal protection as a project impact (even if coastal protection was notnecessarily an objective or goal of the project). But these projects provided littleevidence on the economic value of coastal protection benefits.In the cases where disaster risk reduction benefits were estimated, they were forproject-wide benefits (which came primarily from dikes or other forest benefits)without a breakout for the mangrove component. In one case, the percentage ofdisaster damage that would need to be averted in order for project benefits to exceedcosts was estimated at 4.62 percent, but the likelihood that this target would besurpassed was merely asserted as “likely” without any further analysis. In anothercase, the main economic analysis did not include “unquantifiable” protectivebenefits from mangroves, but a secondary calculation assumed mangrove values of$3,100-$3,800 per hectare (based on extrapolation from estimations used for other,unnamed regions). Where economic returns from afforestation benefits aremeasured, these are usually due to economic benefits from aquaculture rather thanestimating the value of protective benefits. In some cases, attribution of projectimpacts on forest cover is also unclear, because the project overlapped with other(sometimes much larger) programs outside of the project aimed at supportingmangrove afforestation in the same region.A number of papers attempt to estimate the “total economic value” of mangroveand other wetland ecosystems, which includes direct benefits, option values, andexistence values. But most of these focus primarily on forest goods and services(such as timber and fisheries), and many that estimate protective benefits usequestionable methodologies. For example, Gunawardena and Rowan (2005) use areplacement cost approach (“what would be the cost of building a physical coastalprotection system in this area, if mangroves were removed”) but fail to considerwhether it would be optimal to build such a system and without consideringwhether mangroves provide equivalent protective benefits to the proposed physicalbarriers. This method can thus dramatically overstate the protective benefitsprovided by mangroves. Other papers (Ramsar Convention on Wetlands 2005) riskmisstating the benefits of coastal protection by calculating an average benefit per126