Uncertainties in life cycle assessment of waste management systems

Life cycle assessment has been used to assess environmental performances of waste management systems in many studies. The uncertainties inherent to its results are often pointed out but not always quantified, which should be the case to ensure a good decisionmaking process. This paper proposes a method to assess all parameter uncertainties and quantify the overall uncertainty of the assessment.

The method is exemplified in a case study, where the goal is to determine if anaerobic digestion of organic waste is more beneficial than incineration in Denmark, considering only the impact on global warming. The sensitivity analysis pointed out ten parameters particularly highly influencing the result of the study.

In the uncertainty analysis, the distributions of these ten parameters were used in a Monte Carlo analysis, which concluded that incineration appeared more favourable than anaerobic digestion in 91% of the cases.