basescenario

Basescenario, also referred to as the base scenario or baseline scenario, is a reference condition used in forecasting, planning, and risk assessment. It represents the expected state if current trends, policies, and conditions continue without major interventions. The basescenario serves as a neutral starting point against which alternative scenarios are compared.

In practice, basescenarios appear across fields such as climate science, economics, energy planning, and project management. In climate modeling, the base scenario is typically the business-as-usual case used to contrast mitigation or adaptation scenarios. In economics and energy planning, it embodies current policies and market dynamics, projecting outcomes under a continued status quo. In project planning, the basescenario outlines the default trajectory for costs, timelines, and performance.

Methodologically, constructing a basescenario involves specifying a defined time horizon, selecting baseline assumptions (populations, technology, prices, policy environment), and running models with these constants. Results are presented as the reference against which sensitivity analyses and alternative scenarios are evaluated. This process often includes quantifying uncertainty and documenting key drivers that could shift outcomes.

Limitations of basescenarios include their dependence on chosen assumptions and data quality. They are not forecasts of the future, but a reference that can understate risk if tail events or disruptive changes are omitted. Because basescenarios are updated as conditions evolve, they should be treated as dynamic reference points rather than fixed predictions.

See also: Baseline, scenario analysis, reference scenario, business-as-usual, forecast.