Conservation futures 2050: Developing future scenarios to explore potential socio-economic developments and their impact on biodiversity

Discussion We developed four scenarios, which explore possible futures for 2050 by extending current nascent trends to their full potential expression: increased land ownership and management by indigenous people, afforestation using native trees, predator eradication and increasing extreme weather events. These scenarios are not mutually exclusive and could interact, either amplifying or dampening effects. Although these scenarios were developed for Aotearoa New Zealand, many of the underlying trends are applicable globally, and the overall themes and complications highlighted here are equally relevant in other contexts, particularly as other countries invest in their own ambitious conservation and climate-related projects (e.g. affores- tation efforts in treeless environments [72]). The rights and authority of indigenous people over their ancestral lands is gaining momen- tum globally, and is part of the growing recognition of crucial linkages between local and indigenous peoples and ecosystems [35, 73, 74]. In Canada, land settlements have been pro- cessed through negotiations and tribunals [75], while in the United States Native American reservations have some degree of autonomy but are still heavily influenced by the national- level Bureau of Indian Affairs [76]. In Australia, a much-debated referendum proposing an Aboriginal voice to parliament was recently defeated [77], while indigenous groups in Brazil, though officially recognized as holding land tenure, continue to face loss of land and risk of

personal harm as a result of illegal logging and farming [33]. Therefore, a scenario exploring the opportunities and risks associated with the transition of land tenure back to indigenous peoples and increasing integration of indigenous perspectives into national decision-making in conservation can provide meaningful guidance and spark productive conversations in many regions [35, 40]. Similarly, the issue of using non-native vs. native trees for afforestation, forestry and other services has been raised across conservation and carbon capture projects in Africa [78], affor- estation efforts in China [79, 80] and more generally with the deliberate afforestation of tree- less environments [81]. Knowledge of the risks and benefits of large-scale shifts from non- native to native plants for afforestation highlighted here could help planners avoid many of the potential pitfalls and unintended negative consequences of afforestation efforts. Non-native predator eradication from increasingly large island systems has been an impor- tant conservation tool on remote offshore islands for managing biodiversity over the long- term [82]. Recent eradication efforts on larger inhabited islands, such as South Georgia Island and the Gala´pagos, highlight the interest in expanding these techniques alongside resident communities, where socio-economic considerations of large-scale management are crucial to include in long-term eradication plans [55]. The urgency of planning for an increase in extreme weather events is already evident glob-

ally [18, 19, 83]. Conservation work in the climate change space, however, has often focused on gradual changes driven by altered temperature or rainfall, and our ability to make infer- ences about extreme events is limited by their lower frequency and higher variability [21]. Nonetheless, extreme events are likely to drive the most severe climate change impacts over the next few decades, both for human society and for conservation. Management and gover- nance often focus on recovery from extreme events, rather than proactively building resilience. Reactive responses are often more costly and risk creating maladaptive outcomes [63, 84]. Common themes Several common themes emerged across the four scenarios we developed. Overall, the emerg- ing trends revealed the need for a fundamental change in our approach to valuing and manag- ing the natural environment. National and regional decision-making across sectors needs to PLOS ONE Conservation futures 2050 PLOS ONE | https://doi.org/10.1371/journal.pone.0311361 December 12, 2024 9 / 16