Climate change is projected to widen global inequalities in ocean-derived wellbeing

Abstract Climate change threatens well-being from the ocean by disrupting both marine and economic systems, yet its global implications remain unclear. Here, we introduce the Blue Well-being Index (BWI) to assess and predict the performance of ocean-derived well-being for 143 coastal countries under climate change scenarios. We find that although the historical assessment reveals an improvement in the global average BWI score from 2000 to 2021, future projections under high-emission climate scenarios (SSP5-8.5) indicate disproportionate losses across 143 countries. In SSP 5-8.5, global BWI is projected to decline by ~9% by 2100, with adverse effects in nearly 90% of coastal countries. Under the climate-mitigation SSP1-2.6 scenario, with projections indicating that the world could achieve an overall ~11% improvement in BWI across 76% of coastal nations. Climate change exacerbates blue well-being losses, disproportionately affecting both low‑income and high‑income countries, particularly in the natural and social dimensions. These findings underscore the importance of coordinated international mitigation and ocean-conservation efforts to safeguard human well-being and ocean health.