IWRA Proceedings

As shown by IPCC reports, the Mediterranean region is one of the most vulnerable region to climate change and is already experiencing some impacts such as an increase of extreme events (floods, storms, heat waves, droughts...), with significant effect on water resources. Adaptation and mitigation of climate change are therefore major challenges in this region.

The Med-ESCWET project on "the economic valuation of ecosystem services provided by wetlands in terms of adaptation to climate change in the Mediterranean" seeks to promote the adaptation based on wetland ecosystems and to facilitate its integration in national climate change adaptation policies. This three years period project was initiated in 2013 by Plan Bleu, in partnership with Tour du Valat, and is co-financed by the MAVA and the Prince Albert II of Monaco Foundations.

Through four Mediterranean case studies, this project seeks to economically assess some regulating ecosystem services to raise the awareness of policy makers on wetlands importance in adaptation to climate change. As most of the existing studies deals with the impact of these changes on ecosystems, the role of ecosystem in mitigating climate change impacts is still largely to develop, particularly outside of the EU, to be considered in decision-making process.

Mediterranean wetlands are rich and vulnerable ecosystem, increasingly threatened by anthropogenic activities. When preserved, they can deliver a wide range of ecosystem services contributing to human well-being. Therefore, the project first provides a global picture of the ecosystem services panel provided by each pilot site. This inventory was then completed by an economic assessment focused on one service of adaptation to climate change. Using revealed preferences methods, this approach highlights deeply context dependent results, which are not aimed to be compared due to the specificity of each approach carried out:

• The flood control service provided by the natural retention basins of the Lonjsko polje floodplain in Croatia is estimated to a water retention capacity of more than one Billion of m³. Using the replacement costs method, the valuation concludes that the building and maintenance of an equivalent artificial infrastructure (such as several dams) should cost 68,055 €/ha, based over a 100 year time period;
• The coastal protection against storms provided by Vic coastal lagoon in France reduces the impact of an hundred years return period storm to a two years period storm impacts (without any service of protection). This service was valuated through avoided costs method, to a moderate cost of 1197 €/ha, traducing the efficient management of this successfully preserved site;
• The carbon sequestration service was respectively estimated to 1116 and 1734 €/ha/year for Burullus Lake in Egypt and Yeniçaga peatlands inTurkey, using marginal abatement costs or social cost of carbon. The provision of this service is widely influenced by human activities, management history and temporal scale considered.

Except from the methodological lessons learnt, this original exploratory approach in the Mediterranean region is a first step to better consider regulating services as low cost and environmental friendly solutions to mitigate climate change impacts, compared to technological solutions. Integrated in cost benefits analysis, these results could locally inform decision making process in the future, by considering not only the ecosystem services usually traded on commercial markets, but the ecosystem value as a whole.