The transition to renewable energy can disproportionately impact the effectiveness of climate change adaptation, due to regional heterogeneity. Many countries attempt to promote renewable energy to reduce the impact of climate change, but the impacts of national energy policy in the climate vulnerability framework remain little understood. Here, we exploit variations in renewable energy uses to test the effectiveness of climate adaptation policy across the dimensions of climate impact and vulnerability. Using the Fuzzy Analytic Hierarchy Process and panel data regression, we analyze the spatiotemporal correlation between renewable energy transition and climate vulnerability across the world. We find that while renewable energy increases proportionally with climate exposure and sensitivity, many countries exhibit discrepancies between the variation in renewable energy transition and climate vulnerability. The promotion of renewable energy funnels into nations with a higher level of adaptive capacity while bypassing more vulnerable countries. The results signify that existing renewable energy policies can exacerbate climate inequality and undermine the benefits of the transition to renewable energy by neglecting the spatial heterogeneity in climate vulnerability. Our findings provide empirical evidence for the ways in which renewable energy policy can generate spatial inequalities in climate adaptation.