Climate uncertainty and risk

Science informs and empowers. Uncertainty is an inherent part of science and is fundamental to scientific progress. It can propagate through multiple ways in the knowledge generation and dissemination process. Uncertainty can be classified on the basis of its nature (i.e., uncertainty due to imperfection in our knowledge, or the underlying cause of how the uncertainty came to exist), location (i.e., origin of uncertainty in the model outcome), and level (i.e., degree of uncertainty along the spectrum of total determinism to total ignorance). Uncertainty can be assessed, quantified, and constrained through different processes, and in some cases, it can be reduced. To inform sound public choices, and provide accurate and actionable information for decision making, it is important to acknowledge and communicate uncertainties in scientific knowledge. Research scientists focus on the knowledge frontier, where doubt and uncertainty are inherent. Formal uncertainty quantification of computer models is less relevant to science than an assessment of whether the model helps us learn about how the system works.