Carbon footprint estimation of food production systems: The importance of considering methane and nitrous oxide

Abstract

Life Cycle Assessment (LCA) is a useful tool for estimating carbon footprints of the food supply chains. This is illustrated in this paper on the case study of Christmas meal. The results show that the hot spots in the system are the production and distribution of the meal ingredients, causing 86% of the carbon footprint; preparation and consumption of the meal contribute only 14% to the total footprint. In addition to helping identify the hot spots, LCA can also reveal the importance and contribution of different greenhouse gases to the total carbon footprint. This is the main focus of this paper which discusses in particular methane and nitrous oxide. Using Christmas meal as a case study, the results show that CO2 contributes only 42% to the total carbon footprint of the meal, with the remaining 58% being contributed by nitrous oxide and methane. Therefore, excluding these gases from the calculations would significantly underestimate the carbon footprint of food systems. The results also show that biogenic methane does not influence the total carbon footprint significantly.