Which biodiversity futures? Towards coherent design choices for scenarios exploring policy-relevant questions

•1. Decision-makers are under pressure to take transformative action to address the biodiversity crisis. Scenarios can inform these decisions by exploring alternative future states of the world influencing biodiversity loss and the outcomes of actions to address it. However, amid significant methodological diversity, there is limited guidance regarding the scope of scenario design choices available and their suitability for particular applications. This gap generates a fragmented and opaque scenario landscape, hindering the inter-operability of scenarios and introducing the risk that projections or decisions are missing important risks or opportunities for transformative change.
•2. We develop and validate a framework to facilitate coherent design choices (i.e. intentional, transparent and aligned with a question) for scenarios exploring biodiversity futures through two participatory workshops, a scoping review of relevant scenario studies and a retrospective case study reflection. We situate the framework in the United Kingdom as a case study with growing attention on scenarios to inform efforts to reverse centuries of biodiversity loss, but aim to ensure findings are generalisable.
•3. The resulting framework guides users to build a flexible decision pathway including (1) a typology of key policy-relevant questions related to the future of biodiversity, (2) key design choices in the scenario approach and (3) a co-occurrence analysis that shows the prevalence of design choices for responding to policy-relevant questions, thereby highlighting more established design choices versus areas of novelty or innovation.
•4. The retrospective case study reflection suggests how the framework can (a) facilitate a more intentional and transparent approach to using scenarios in ways that cater to the policy-relevant questions they are meant to answer, (b) expand options considered to explore a range of indirect and direct drivers of biodiversity loss and (c) provide a common language to aid in communication across disciplines and perspectives.
•5. Our findings suggest that flexible uptake of the framework can facilitate a more coherent and enriched scenario landscape, informing decisions that account for a wide range of risks to biodiversity and surfacing options for halting and reversing biodiversity loss.