Mitigating greenhouse gas emissions in agriculture: From farm production to food consumption

Greenhouse gas (GHG) emissions from agriculture can be mitigated from both supply (production) and demand (consumption) sides. In this study the carbon footprint (CF) of a range of 26 crop and 6 livestock products was calculated using national statistical data and used as an indicator to assess the climatic impacts of agriculture from farm production to food consumption in China. Of the products assessed, meat had the highest CF (6.21 kg CO2-equivalent (CO2-eq)/kg), and vegetable had the lowest (0.15 kg CO2-eq/kg). The CFs of fruit, legume, grain crop, oil crop, milk, industrial crop and poultry egg were 0.31, 0.46, 0.77, 0.95, 1.47, 2.96 and 4.09 kg CO2-eq/kg, respectively. Methane emissions from paddy rice and emissions from fertilizer application were the largest contributors of about 36∼93% of CFs for crop production, whereas GHG emissions from forage, enteric fermentation and manure treatment accounted for more than 96% for CFs of livestock and poultry production. Significant differences between CFs were found across different management patterns and farm scales. GHGs emissions estimated from supply side food production are currently 912.5 kg CO2-eq/capita/year, which was considerably higher than that estimated from consumption being 379.6 kg CO2-eq/capita/year - which may be attributable to export, waste, or to the use of crops as feed for livestock. The CF for dining out was 2.87 kg CO2-eq/capita/meal, which was higher than home dining at 1.57 kg CO2-eq/capita/meal. We conclude that both improved agricultural management and dietary consumption changes have the potential to provide considerable GHG mitigation in China.