Comparative assessment of vulnerability among small island developing states using a composite index

Small island developing states (SIDSs) are widely recognized as among the most climate-vulnerable nations. Yet, uncertainty remains about which specific islands face the most significant risks and whether geographic remoteness intensifies vulnerability. This study examines climate vulnerability across 57 SIDSs using a composite vulnerability index (VI) that incorporates social, environmental, remoteness, and economic dimensions under four alternative weighting scenarios. Additionally, it investigates the relationship between geographic isolation and vulnerability through Spearman’s correlation analysis. Results reveal variations in vulnerability levels (VI = 0.28–0.62), with Niue, Bermuda, and Guam consistently ranking as the most vulnerable across weightings, while Papua New Guinea, Haiti, Trinidad and Tobago, and Timor-Leste consistently rank as the least vulnerable. Surprisingly, geographic remoteness demonstrates weak correlations with most vulnerability indicators. Therefore, the study suggests that remoteness may function as a conditional rather than deterministic vulnerability factor. The study concludes that effective interventions for SIDSs require moving beyond simplistic assumptions linking geographic isolation to heightened vulnerability. International support mechanisms should prioritize context-specific assessments over remoteness-based classifications.