30×30 biodiversity gains rely on national coordination

Protecting 30% of land by 2030 is an invaluable opportunity to combat the ongoing biodiversity crisis, but critical questions remain regarding what biodiversity to prioritize, how to coordinate protection, and how to incorporate global change. Here, we evaluate how well different 30×30 expansion scenarios capture the climatically viable ranges of Canadian terrestrial vertebrates, plants, and butterflies. We find that national coordination protects vastly more biodiversity (65% of species; 40% of species-at-risk) than regional approaches, which safeguard at least 33% fewer species and 75% fewer species-at-risk. Whereas prioritizing different taxa or biodiversity facets (e.g., phylogenetic diversity) incur smaller trade-offs. Surprisingly, national priorities closely match transnational ones, indicating that national coordination could efficiently contribute to global targets while protecting Canada’s biodiversity at large.