Subsistence-oriented communities in tropical coastal areas face the greatest threat from climate change, with consequences manifesting through diminishing returns from small-scale fishing and farming ventures. The complementary climate, sustainable development, and biodiversity conservation policies target reducing climate risks, but effective policy outcomes depend on a thorough understanding of system-wide climate risk, community adaptation potential and gaps, and possible economic losses. Using four countries in the Western Indian Ocean (WIO) region as a case, we present a framework for quantifying climate risk to subsistence-oriented coastal communities. On average, economic losses of ecosystem services are predicted to increase with increasing climate risk, with annual losses of up to 23% and 32% of total economic value (~ US$ 516,828,468/year) under SSP2-4.5 and SSP5-8.5 scenarios by 2050, respectively. A comprehensive assessment of climate risks, ecosystem service value and cost of climate inaction can inform policy actions aimed at adapting, mitigating, and compensating for the loss and damage caused by climate change.