Urgent climate action is needed to ensure effectiveness of protected areas for biodiversity benefits

The intertwined crises of biodiversity loss and climate change pose a significant sustainability challenge, threatening ecosystems and human well-being globally. Yet, the nuanced interplay between these challenges is often understated in policy dialogs. Global biodiversity targets, including 30% protection of the Earth's surface by 2030, may fall short without robust climate change mitigation. Here, we illustrate that conservation through protected areas can effectively preserve forest productivity and carbon capture, which depend on tree diversity. However, failing to mitigate climate change diminishes the effectiveness of these areas, especially in warmer biomes. Even with optimal protected area selection, preserving tree diversity-dependent productivity could be compromised without significant climate change mitigation. Our findings emphasize the need to integrate climate change mitigation into biodiversity conservation policies to ensure the success of the 30 × 30 targets and sustain the ecosystem benefits biodiversity provides to society.