Carbon footprint estimation of food production systems: the importance of considering methane and nitrous oxide. (Greening the Food Chain, 4.)

摘要

The Life Cycle Assessment (LCA) is a useful tool for estimating carbon footprints of the food supply chains. This is illustrated in this paper by the case study of Christmas meal (meat, vegetables and accompaniments). The results showed that the 'hot spots' in the system were the production and distribution of the meal ingredients, causing 86% of the carbon footprint; preparation and consumption of the meal contributed 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 methane and nitrous oxide in particular. Using the Christmas meal as case study, the results showed that CO₂ contributed 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 showed that biogenic methane did not significantly influence the total carbon footprint.