scenario

Representations of possible futures for one or more components of a system, particularly for drivers of change in nature and nature's benefits, including alternative policy or management options. Exploratory scenarios (also known as explorative scenarios or descriptive scenarios) are scenarios that examine a range of plausible futures, based on potential trajectories of drivers - either indirect (e.g. socio-political, economic and technological factors) or direct (e.g. habitat conversion, climate change). Target-seeking scenarios (also known as goal-seeking scenarios or normative scenarios): scenarios that start with the definition of a clear objective, or a set of objectives, specified either in terms of achievable targets, or as an objective function to be optimized, and then identify different pathways to achieving this outcome (e.g. through backcasting). Intervention scenarios are scenarios that evaluate alternative policy or management options - either through target seeking (also known as goal seeking or normative scenario analysis) or through policy screening (also known as ex-ante assessment). Policy-evaluation scenarios are scenarios, including counterfactual scenarios, used in ex-post assessments of the gap between policy objectives and actual policy results, as part of the policy-review phase of the policy cycle. Policy-screening scenarios are scenarios used in ex-ante assessments, to forecast the effects of alternative policy or management options (interventions) on environmental outcomes.|scale|.