EPA Issues New Guidance on Environmental Models · Environmental Leader
In order to help make environmental impact and life cycle assessment models credible, the EPA has issued a guidance paper (PDF)
“This guidance recommends best practices to help determine when a model, despite its uncertainties, can be appropriately used to inform a decision. Specifically, it recommends that model developers and users:
- Subject their model to credible, objective peer review;
- Assess the quality of the data they use;
- Corroborate their model by evaluating the degree to which it corresponds to the system being modeled;
- Perform sensitivity and uncertainty analyses. Sensitivity analysis evaluates the effect of changes in input values or assumptions on a model’s results. Uncertainty analysis investigates the effects of lack of knowledge and other potential sources of error in the model (e.g., the “uncertainty” associated with model parameter values). When conducted in combination, sensitivity and uncertainty analysis allow model users to be more informed about the confidence that can be placed in model results.
A model’s quality to support a decision becomes better known when information is available to assess these factors.”
