Changes in global climate are increasingly having adverse impacts on human populations and natural systems. This has resulted in increased efforts to come up with options that can mitigate the impacts, as well as help to adapt to already occurring changes.
Ecosystem based adaptation is used by a number of organisations and in many developed and developing countries as a means for climate adaptation, especially at the community level. It is also applied for disaster risk reduction. Still, there is a propensity of policy makers to implement traditional engineering solutions for adaptation rather than investing in EbA. There is, therefore, a need to raise further awareness on the use of nature based solutions.
An important approach to promote investment in EbA is to identify its economic costs and benefits. This study therefore reviewed a number of projects in Costa Rica, India, Mexico, Peru, Philippines and Tanzania, to assess existing data and knowledge gaps regarding the economic values of EbA projects.
The literature review showed that climate change is likely to change the productivity and benefits from the agriculture, fisheries and forestry sectors. These sectors are important economic contributors to these countries and provide extensively to the national exchequer. Already, impacts are being observed in terms of lower yields and productivity as well as loss of livelihoods and security.
Cost-benefit analyses (CBA) of projects in these countries showed that EbA projects provided many benefits and in general helped to increase resilience and decrease vulnerabilities. However, it was clear that there were extensive knowledge gaps and detailed economic valuation/ CBA studies need to be undertaken to make a stronger case for ecosystems based adaptation. Currently, the studies are context specific, do not include opportunity costs and much of the benefits are in qualitative terms.
Detailed assessments will help to establish the importance of EbA, if they are based on robust methodologies that are developed with appropriate guidance; differentiate between different costs and sectors; incorporate biodiversity and species; are based on gender (and other groups) disaggregated data; and account for co-benefits. This can be undertaken at two scales: undertaking CBA before project initiation, to help stakeholders decide on investment options and actions. More importantly however, there is a need to undertake analyses of ongoing and completed projects in the studied countries, to understand and gather the evidence for the effectiveness of EbA projects as compared to other solutions.