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1000 — Uncertainty quantification

This chapter introduces uncertainty quantification (UQ) through a concrete sustainability problem: calibrating a simplified climate model to historical observations.

In sustainable aviation studies, uncertainty is unavoidable:

  • uncertain technology trajectories,
  • uncertain policy and demand scenarios,
  • uncertain non-CO₂ effects,
  • uncertain model parameters and structural assumptions.

UQ is not an “add-on”; it is how we avoid false certainty and misleading point estimates.


Exercises in this chapter

1000.UQ.1 — Bayesian inference for a simple climate model

A full Bayesian calibration workflow:

  • define a forward model (ODE-based climate model),
  • identify uncertain parameters,
  • specify their prior distributions,
  • define a likelihood against historical observations,
  • infer posterior distributions using MCMC (emcee),
  • perform posterior predictive evaluations,
  • explore sensitivity (time-dependent Sobol-style variance contributions).

➡️ Exercise page →


Learning outcomes

After completing this chapter, you should be able to:

  • Explain the difference between:

    • parameter uncertainty,
    • data uncertainty,
    • model discrepancy (structural uncertainty)
  • Build a Bayesian workflow: prior → likelihood → posterior

  • Interpret MCMC results (convergence, autocorrelation, degeneracy)
  • Produce posterior predictive checks and assess goodness-of-fit honestly
  • Understand why uncertainty can matter more than mean predictions in decision contexts