Michaelsen, PatrikSundström, AkselJagers, Sverker C.2024-12-202024-12-202024-121653-8919https://hdl.handle.net/2077/84510Rapid global expansion of protected areas is critical for safeguarding biodiversity but depends on political action for successful implementation. Following ratification of the Kunming-Montreal Global Biodiversity Framework, most countries face an unprecedented increase in area-based conservation in adhering to its Target 3: conserving 30% of land, waters, and seas by 2030. These expansions prompt difficult trade-offs between conservation, social and economic interests. A key factor in securing legitimacy and practical feasibility for expansion programs is understanding what factors determine public support for them. Using novel survey and conjoint experiment data we show that, in eight countries across five continents, public opinion is 1) strongly in favor of the “30-by-30”-target, and 2) surprisingly consistent about policy priorities for the design of both international and domestic expansion regimes. We find that, at the international level, support increases with protection responsibilities equally split between countries, rich countries bearing higher costs, more countries cooperating, and placement trade banned. At the domestic level, support generally increase when nature-values are prioritized over social or economic values, and in many countries decrease when costs are borne by a general tax increase, parks are managed by private companies, and when access to parks is restricted. Together, our results demonstrate how protected area expansion policies can be shaped in line with public opinion and facilitate achieving 30% protected areas by 2030.engText