*2.3. Methods*

The research questions were addressed using a multi-level, mixed-methods approach (Table 1), where each research question was addressed using the same methods. Fieldwork was undertaken between August and October 2017.


**Table 1.** Summary and sample size of multi-level and mixed-method research approaches used across case studies.

Stakeholders in the project areas were identified through literature review and interviews with project developers. Sampling criteria included direct targeting of community beneficiaries who were formally employed by Eden or registered with Makira. To avoid sampling biases, after the first local contact was made by the project developer, the remaining participants were chosen in the field, according to their willingness to participate and keeping a balanced gender and age representation based on information derived from local project sta ff. Project perspectives were addressed through 13 semi-structured expert interviews with: regional-level policy makers (n = 3), scientists (n = 1) and project developers (n = 5 Eden, n = 4 Makira) identified through snowball sampling, with questions focused on background and stakeholder analysis, project achievements and challenges, community engagement, monitoring and evaluation, and policy implications (Supplementary Material 1).

Two study villages (those with the longest implementation histories) were selected under each project. In Eden, these covered its coastal activities as the core of Eden's operations. In the Makira case, two villages of easier access were targeted from among the seventy-three villages within which the project operates. By focusing on two Makira villages, the data produced a valuable understanding of key project benefits and challenges, at a comparable scale to the Eden case. Community-perspectives were addressed through 60 semi-structured interviews with local workers and project beneficiaries (n = 50 with Eden, out of a total of 234 direct beneficiaries across the two study villages, and n = 10 with Makira, out of 95 direct beneficiaries across the two villages), 4 focus groups (n = 2 Eden, each with n = 15 participants, n = 2 Makira, respectively with n = 5 and n = 15 participants), and 4 participatory site visits (n = 2 Eden, each with n = 10 participants, n = 2 Makira, each with n = 5 participants). Semi-structured interview samples sizes align with approaches followed in qualitative research more broadly [36]. The larger sample of interviewees under Eden is due to the higher number of direct beneficiaries in each village compared to Makira. Open invitations were circulated by village heads prior to carrying out focus groups and site visits, with sample sizes ranging between 5 and 15 participants and being aligned with approaches followed in comparable studies [37]. Questions expanded the themes covered in expert interviews, emphasizing the perceived opportunities and challenges to deliver adaptation, mitigation, and development at the community-level (Supplementary Material 2).

Data were input into a modified analytical framework, originally developed for assessing ecosystem restoration and rehabilitation projects in South Africa (Table 2). Adaptation is considered as people's capacity to "anticipate and respond to change, to minimize the consequences, to recover, and take advantage of new opportunities" to deal with climate impacts [10] (p. 117). Mitigation is defined as the reduction of emissions of greenhouse gases and increased uptake of such gases by the Earth system such that atmospheric greenhouse gas concentrations decline [38]. Development is defined as sustaining SDG achievement through the enhancement of short and long-term capabilities, assets and activities needed for a means of living [16,39]. We acknowledge that neither adaptation nor development happen separately, and some of their dimensions might overlap. Results are grounded in the indicators used in the analytical framework, the utility of which lies in its qualitative assessment and integration of local-level perceptions of co-benefits and challenges in climate change and development practice. Where quantitative measures of climate impacts are absent, the gathering of perceptions of such climate impacts allows for trends and patterns to be identified. Patterns of categories from responses were grouped under key themes that were used to adapt the original analytical framework (Table 2). Through this thematic analysis, phrases from interview notes (including semi-structured interviews, field visits and focus groups) were assigned an ID based on their related type of benefit, categorized into relevant themes and inserted into the analytical framework. Data was analyzed drawing on comparative qualitative analysis approaches, where the same set of indicators used in the framework was compared across case studies [40].

**Table 2.** Analytical framework for adaptation, mitigation and development co-benefits and challenges of case studies: definitions and indicators.



**Table 2.** *Cont.*

Data generated by one method was triangulated and validated by the other methods. While expert interviews were carried out independently by the lead researcher, community-level data collection involved two local translators, with interview notes taken by the lead researcher in English.
