BACKGROUND:
As effects of climate change intensify, ethical considerations become critical for populations disproportionately affected by climate-induced health hazards. While EcoHealth, One Health, and Planetary Health frameworks emphasize stakeholder co-creation, existing ethical guidelines remain theoretical and top-down, rarely consulting affected communities. This two-phase study triangulates perspectives of communities, researchers, and ethics committees to develop grounded ethical recommendations for climate-health research.

METHODS:
We gathered community perspectives through interviews and focus groups discussions (FGD) with Indigenous populations in India (16 interviews, 2 FGD) and coastal communities in the Philippines (16 interviews, 8 FGD), exploring experiences of ethical processes and practices. This informed the development of vignettes and corresponding statements for an online 2-rounds Delphi study with researchers and ethics committee members (52 respondents round 1; 23 round 2).

RESULTS:
A central tension emerged between institutional ethics emphasizing individual procedural consent and extractive knowledge production versus communities' expectations of collective governance and relational accountability. Communities stressed reciprocity as foundational: willingness to participate and share data depends on researchers sharing their expertise, disseminating actionable findings, responding to community needs, and building long-term trust. Reciprocity was further described as requiring research materials in local dialects, respecting the traditional decision-making processes, and engaging community co-researchers. Delphi respondents emphasized balancing long-term climate objectives with participants' immediate rights, safety, and dignity. Strong consensus emerged on anticipating climate-related burdens, prioritizing participant well-being even when requiring protocol deviations, enabling context-appropriate compensation for contributed labor, and valuing Indigenous and experiential knowledge alongside scientific data. Though consensus was strong, feasibility was often questioned, and institutional rigidity was identified as a main barrier to grounded ethical practice.

CONCLUSIONS:
Findings highlight the necessity for ethical frameworks explicitly addressing climate-specific vulnerabilities, reformed funding structures enabling ethical practices currently deemed aspirational, and methodological pluralism integrating quantitative and qualitative approaches with Indigenous knowledge systems as standard practice.