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Global food systems and their share of anthropogenic GHG emissions

Written by: Karen Spencer

A new research article discusses a new global food emissions database, estimating GHG emissions from, production to consumption and end-of-life waste disposal, including land-use change, processing, packaging, transportation and waste management. In 2015, global food-system emissions amounted to 34% of total manmade GHG emissions, with over 70% of this coming from agriculture and land use/land-use change activities.  What does this mean for agriculture policy in Canada?

The authors summarize the data from 1990 to 2015, noting that in 2015 food-system emissions amounted to 18 Gt CO2 eq globally, representing 34% of total manmade GHG emissions. The absolute emissions are 12% higher than in 1990 while population has grown by 38% in that period, indicating an increase in efficiencies of food production, and a “decoupling” of emissions from population growth.

The human food system requires farming, harvesting, catching, transporting, processing, packaging, distribution, cooking, and disposal of residuals throughout this chain. Each step requires energy and produces GHG emissions, plus inputs such as fertilizers and products such as cattle produce non-combustion GHG emissions. The authors document the creation of a new database that considers GHG emissions from our global food system using of a number of databases already in place – these include the National Inventory Reporting under the United Nations Framework Convention on Climate Change (UNFCCC), the Emissions Database of Global Atmospheric Research (EDGAR), GAINS (a GHG emissions model developed under the International Institute for Applied Systems Analysis IIASA), and FAOSTAT (the Food and Agriculture Organization of the United Nations), to name a few. The database summarizes these emissions on a global and country level.

Although other studies have considered these estimates in the past, this is the first paper which includes country level figures. The results from the authors’ work indicate one third of global GHG emissions comes from our food system. The authors noted one-third of food-system GHG emissions, about 32%, come from land use and land-use change activities (LULUC). 39% of emissions are from the production of food, bringing foodstuffs to the “farm gate”, while the remainder, 29%, include distribution (transport, packaging, retail, processing, consumption and end-of-life disposal).

By country, the biggest emitters were those with some of the largest populations: China (13.5% of the global total), Indonesia (8.8%), the United States (8.2%), Brazil (7.4%), the European Union (6.7%) and India (6.3%).

Because the data was analyzed over twenty-five years, the authors noted a number of trends and patterns: in 1990, emissions from the global food-system comprised 44% of mankind’s total GHG emissions, while at 2015 it made up 34% of the total. If we consider developing countries only, the percentage of total GHG emissions related to food-system fell from almost 70% to about 40% of the total. Developing countries significantly increased their emissions in non-food areas while reducing land-based emissions through a large reduction in deforestation.

88% of emissions from LULUC are from developing countries and are mainly composed of carbon losses from deforestation and degradation of organic soils. Models show that much of these emissions are associated with food consumption in industrialized countries. Emissions from food-systems-related energy use increased by 15% globally from 1990 to 2015; however, energy-sourced emissions increased by 50% in developing countries as agricultural production in their food production systems became more mechanized and with increased use of fertilizers and pesticides, in addition to rapid expansion to provide food for a growing domestic population and also for export.  Energy needs for distribution, including transport, packaging and retail, processing, consumption, and end-of-life disposal, increased from 1990 to 2015 for both developing and developed countries. Emissions from fluorinated gases (F-gases) were small but were predominantly from industrialized countries, and were mostly linked to refrigeration in the retail stage.

The authors noted the data showed a global food system characterized by an increase in convenience and processed food, and increasing globalization of food supply chains. They note in order to function, the food system requires materials and energy for processing, packaging, transportation and storage. Of these, the biggest is packaging, representing about 5.4% of total food-system emissions in 2015. Transportation is a close second, at 4.8% of total food-system emissions; however 81% of this figure is local tor regional transport via road, with 15% from rail and a very small amount related to navigation or aviation. GHG emissions from the retail sector increased 3.6 times in the United States between 1990 and 2015.

Total food-system emissions increased by 12% from 1990 to 2015, but substantially decreased per capita, falling by 20% in that same time. The article included a detailed Sankey diagram for GHG emissions from the food system in 2015, shown at a global level, in addition to all industrialized countries and all developing countries.

The authors observe that developing countries typically see total GHG emissions from the food sector rise over the years as they substantially develop their domestic agriculture systems in order to fulfill their needs and grow in exports to developed countries. As in the example of China, at a certain point, more of the economy moves toward non-food value-added sectors, piled on top of food emissions. In addition, substantial steps have been seen in countries such as Brazil where GHG emissions fell by 30% from 1990 to 2015 due to substantial decreases in deforestation rates, through changing agriculture practices. While developing countries increase their emissions and efficiencies, industrialized countries have seen relatively flat emissions with high efficiencies and decoupling of food-sector emissions with population or overall GDP. Food emissions are becoming increasingly determined by energy use, industrial activities, and waste management.

Some areas such as packaging and local transport will be targets for specific sectorial energy efficiency and decarbonisation policies, while other areas such as land-based and livestock emissions, will be potentially more impacted by consumer need and demand, and will perhaps require a different type of mitigation policy. In addition, the delicate balance of global supply and demand between developing and developed countries is observed, as the authors note the substantial emissions in developing nations created from product demand in industrialized nations.

For further reading, the full article is located in the reference below.


  1. Crippa, E. Solazzo, D. Guizzardi, F. Monforti-Ferrario and others. “Food systems are responsible for a third of global anthropogenic GHG emissions,” Nature Food (2021), March 8, 2021.

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