Uncertainty means lack of knowledge. Deep uncertainty extends the traditional uncertainty definition with two additional caveats: 1) inability to make well-informed future projections of a system, based on available data and understanding, and 2) inability to reduce this uncertainty, for near-term decision making, by gathering additional information. The concept of deep uncertainty may also include consideration of the stakeholders’ preferences regarding outcomes. Stakeholders’ preferences are politically motivated and seek to gain political power or economic advantages for their tribe. Consequently, the political power components of deep uncertainty are not traditionally included in engineering, scientific, or planning uncertainty.