The study is motivated by high levels of chronic kidney disease (CKDu) in climate-impacted areas of Sri Lanka. Using a convergent mixed methods design, the research will collect cross-sectional quantitative data from adult participants in selected districts representing high and low climate impact and CKDu burden. Validated tools such as the GHQ-12 and PHQ-9 will measure psychological distress; qualitative data will explore lived experiences and coping mechanisms. Findings will fill critical gaps in the climate-mental health evidence base, contribute to scholarly understanding of environmental determinants of mental health in LMICs and guide future intervention research in the country.