Barriers to ecosystem-based adaptation (EbA), which is part of the broader nature-based solutions (NbS) category, remain poorly understood and assessed. This article addresses this research gap, by proposing a structured analytical framework to understand barriers and applying it to 24 coastal EbA projects deployed in French tropical island territories. This framework considers four dimensions of barriers: categories, origins, impacts on the adaptation process, and temporalities. The findings highlight three main barriers relating to institutions, governance, politics, laws and regulations (35%); awareness, knowledge and technical resources (20%); and finance (15%). Most barriers are objective (80%), contextual (51.7%) and not adaptation specific (63.3%). Prevalent adaptation-specific barriers are the lack of or weakness of EbA-oriented policy and tools (59.5%) and lack of a future-oriented risk- and solution-based approach (27.0%). Most barriers (56.7%) affect two stages of the adaptation process (readiness and implementation) and were not overcome over the lifetime of the projects (53.3%). Thirteen solutions to barriers were implemented, with information, knowledge and awareness sharing or strengthening and increased coordination efforts being the most utilised and successful. This study highlights the benefits of including a barrier-oriented analysis in the evaluation of adaptation projects and proposes an operational and transferable framework to do so.

Ecosystems across the globe are vulnerable to the effects of climate change, as are the communities that depend on them. However, ecosystems can also protect people from climate change impacts. As the evidence base strengthens, nature-based solutions (NbS) are increasingly prominent in climate change policy, especially in developing nations. Yet intentions rarely translate into measurable, evidence-based targets. As Paris Agreement signatories revise their Nationally Determined Contributions, we argue that NbS are key to meeting global goals for climate and biodiversity, and we urge researchers to work more closely with policy-makers to identify targets that benefit both people and ecosystems.

To guide investments in ecosystem-based adaptation (EbA) in developing countries, numerous stated preference valuation studies have been implemented to assess the value of ecosystem services. These studies increasingly use time payments as an alternative to money. There is limited knowledge, however, about how to convert time to money and how the type of payment affects willingness to pay (WTP). In this study, the results of choice experiments using time and money payments are compared in the context of EbA measures in Vietnam. Six, of which five individual-specific, conversion rates are applied. WTP estimates are found to be higher for time payments. Moreover, the type of payment vehicle as well as the conversion rate has substantial effect on mean WTP and WTP distributions. We discuss implications of these results for the conversion of time to money and the use of resulting WTP estimates in cost benefit analyses in developing countries.

In the face of an already changing climate, conservation practitioners and local communities face the major challenge of how to plan for a future climate. In data-sparse areas of the world, where action is often most needed, the daunting scope of the problem can lead to inaction. This paper shows that climate adaptation planning can be accomplished successfully with publicly and globally available data by linking science and stakeholders through a facilitated process. Working with local stakeholders in the western Tanzanian Greater Mahale and Greater Gombe Ecosystems, future climate projections produced using Climate Wizard and analyses of literature provided an understanding of the climate vulnerabilities of local ecosystems and human livelihoods. Facilitated workshops enabled local stakeholders to use this information to develop conceptual models and hypotheses of change for these systems, and to identify possible modifications to conservation plans. Here, climate change planning required the modification of most current conservation strategies, developing some new strategies and abandoning others. The paper indicates that climate adaptation planning is achievable even in data-sparse rural and developing areas, but requires appropriate scientific analyses, engaged stakeholders and a facilitated process.