Impact Trust • Working glossary

Radical uncertainty

Uncertainty so profound you cannot even know the range of what might happen. Distinguished from measurable risk.

Details

Our Take
Risk is quantifiable uncertainty; radical uncertainty is not. This matters because most institutional planning assumes you can model risks -- but the polycrisis operates in radical uncertainty territory where models break down. Preparedness cannot be based on prediction alone. You need the capacity to respond to things you could not have imagined.
Synonyms/Variants
Deep uncertainty; Knightian uncertainty; Unknowable risk; VUCA (related but broader)
Typical everyday wording
When you cannot even know the range of what might happen.