Expanding the global protected area network is critical for addressing biodiversity declines and the climate crisis. However, how climate change will affect ecosystem representation within the protected area network remains unclear. Here we use spatial climate analogs to examine potential climate-driven shifts in terrestrial ecoregions and biomes under a +2 °C warming scenario and associated implications for achieving 30% area-based protection targets. We find that roughly half of land area will experience climate conditions that correspond with different ecoregions and nearly a quarter will experience climates from a different biome. Of the area projected to remain climatically stable, 46% is currently intact (low human modification). The area required to achieve protection targets in 87% of ecoregions exceeds the area that is intact, not protected, and projected to remain climatically stable within those ecoregions. Therefore, we propose that prioritization schemes will need to explicitly consider climate-driven changes in patterns of biodiversity.