Accounting for uncertainty in life cycle assessments – Benchmarking carbon footprints of western European dietary patterns to 1.5- and 2-degree climate target compatible lifestyles using a probabilistic approach
Johanna Manon RÜTT, University of Cologne, Germany
Ever rising greenhouse gas emissions call for socio-ecologic lifestyle transitions to mitigate climate change. Globally, western European lifestyles are among the most carbon-intensive ones. Also, omnivorous western European diets are associated with substantial climate impacts, necessitating modified food systems to remain below a 1.5- or 2-degree global warming. Efficient reduction strategies require accurate and transparent information. However, diet climate impacts are uncertain due to variability and uncertainty in data collection and processing.
The objective of this study is to support decision-making for climate change mitigation by evaluating carbon footprints of western European dietary patterns (vegan, vegetarian and different types of meat consumption) and benchmarking them to 1.5- and 2-degree climate targets, whilst accounting for uncertainties and variabilities regarding carbon intensities of animal-based foods. An extensive literature review provides value ranges for climate impacts to carry out uncertainty and sensitivity analysis via Monte Carlo simulation.
Probability distributions for dietary pattern carbon footprints show that the fewer animal-based foods consumed in a diet, the lower corresponding emissions. Beef, fish/seafood and cheese have the strongest impact when consumed in high amounts. Switches from diets high in animal-based products to those low in animal-based foods yield the highest greenhouse gas emission savings. According to my calculations, only the vegan diet is in line with the emission budget to remain below a 2-degree global warming. Greenhouse gas emissions could be decreased by reducing animal-based food consumption, diminishing food waste and excess food consumption as well as enhancing agricultural production efficiency.
Regarding uncertainties in greenhouse gas emission calculations further substantiates carbon reduction policies and initiatives, boosting a successful and sustainable socio-ecologic transformation.
Mots clés : life cycle assessment|greenhouse gas emissions|western European diet|food supply chain|Monte Carlo simulation
A103178JR