Environmental Impacts
The relationship between agrifood systems and the environment is complex, with agrifood systems contributing to climate and environmental changes and, at the same time, being vulnerable to those changes. Although a vast range of data on the environmental impacts of food production is already available, there is a lack of information about the environmental effects of individual food choices and consumption. This information is important because consumers can be a powerful lever for change through their food choices. The purpose of the FAO/WHO GIFT environmental infographics is to estimate the impact of diets on the environment using individual-level quantitative dietary intake data. These environmental impact estimates can provide evidence to support policies and programmes for sustainable healthy diets.
The infographics present estimates of the environmental impact of food consumption for three environmental impact measures: greenhouse gas emissions, water use and land use. These measures represent three key impacts of human activities on the planet:
- ‘Greenhouse gas emissions’ measures global warming potential and is expressed in mass of carbon dioxide equivalent (kg CO2 eq);
- ‘Water use’ estimates the use of a valuable natural resource and is expressed in volume (litres); and
- ‘Land use’ estimates the areas occupied by food production and is expressed in units of area (square meters (m2)).
Environmental impact values are based on Poore and Nemecek (2018)1, a globally reconciled and methodologically harmonised dataset that provides multiple environmental impacts of foods from ∼38,000 farms in 119 countries, including low- and middle-income countries. The information comes from a comprehensive meta-analysis of life cycle assessment (LCA) studies summarising the impacts of 43 agricultural food commodities that represent ~90% of global dietary energy and protein intake. The global representativeness of the environmental values was validated by the authors comparing average and 90th-percentile yields to FAOSTAT data. The dataset provides global average values for food commodities, and also the 5th, 10th, 50th, 90th and 95th percentiles. The system boundaries considered by Poore and Nemecek start with the extraction of resources needed to produce inputs for agricultural production, end at the retail store, and include processing, packaging, transportation and losses from farm to retail point. Post-retail stages (cooking and consumer losses) are not considered owing to high variability and low data availability1. In the FAO/WHO GIFT infographics, greenhouse gas emissions refer to values calculated following the IPCC 2013 methodology, while water use refers to freshwater withdrawals.
1 J. Poore, T. Nemecek. Reducing food’s environmental impacts through producers and consumers. Science 360, 987-992 (2018). DOI: 10.1126/science.aaq0216
To facilitate the matching between the individual-level dietary intake data available in FAO/WHO GIFT to greenhouse gas emissions, water use and land use values, a dataset was developed to match environmental impact values to the base terms of FoodEx2, a description and classification system developed by the European Food Safety Authority (EFSA). The dataset, herein called “FoodEx2-environment dataset”, was developed by Reynolds et al.2,3 and revised in collaboration with the authors.4
Environmental data from the 43 agricultural food commodities in Poore and Nemecek were manually matched to over 4500 base terms from the FoodEx2 Exposure hierarchy, using the closest food type. Where no environmental values existed for a food type, proxy values from a similar food item were used. For example, beans and lentils were allocated values from “other pulses”. If the FoodEx2 base term referred to a complex product (i.e., mixed dishes and recipes containing more than one ingredient), the matching was made considering the largest recipe ingredient (by raw weight). Some adjustments were made to the environmental impact values of recipes to avoid, as much as possible, over- or underestimation.
2 Reynolds C, Tereza da Silva J, Garzillo JMF, Frankowska A, Kluczkovski A, Rose D, et al. Comparison of Greenhouse Gas databases using FoodEx2 codes. In: 7th Annual Agriculture, Nutrition and Health (ANH) Academy Week (20th-30th June 2022).
3 Reynolds C, Rivera XS, Frankowska A, Kluczkovski A, Tereza da Silva J, Bridle SL, et al. A pilot method linking greenhouse gas emission databases to the FoodEx2 classification. In: Livestock, Environment and People (LEAP) Conference 2019. Oxford (2019).
4 Tereza da Silva J, de Quadros VP, Garzillo JMF, Takacs B, Balcerzak A, Frankowska A, et al. Development and evaluation of a dataset to assess the environmental impacts of individual food consumption. [Manuscript in preparation].Individual-level dietary intake datasets are first matched to the FoodEx2-environment dataset. Every FoodEx2 base term is then associated to a food group and food subgroup, which are used by the FAO/WHO GIFT platform to produce the infographics using standardised queries for all datasets and countries.
Foods can be grouped into different categories based on the purpose of the analysis. The food groups presented in the environmental infographics are the same as the FAO/WHO GIFT nutrition-sensitive food groups, while some differences occur for the food subgroups. In particular, the environment-sensitive subgroup level separates animal-source from plant-source items to the extent possible, and presents the estimated environmental impacts from different types of meat, fruits, vegetables, etc.
This infographic shows the estimated average greenhouse gas emissions (kilograms of carbon dioxide equivalents (kg CO2 eq)), water use (litres) and land use (square meters (m2)) of the entire diet and different food groups, subgroups, and food items, per person per day. The calculations consider all individuals in the population: consumers and non-consumers. Consumers are those individuals who consumed the foods of interest during the survey period, and non-consumers are those who did not.
Quantities of foods reported as consumed are multiplied by the environmental impacts of that given food. This is a similar approach to the one used to assess nutrient intakes using food composition data. After calculating the environmental impact per food consumed, the impacts of the entire diet and by food groups are calculated by summing up all foods consumed by an individual per day. If an individual has multiple 24-hour dietary recalls/records, an average of the number of days of consumption is considered.
This infographic offers an understanding of the contribution of different foods and food groups to the total environmental impact of diets, and how the composition of the diet may influence its environmental impact.
The environmental impacts of diets are usually reported per weight or volume (kilograms or litres) of food or beverage consumed. While this approach is simple and easy to understand, it does not express food functionality, i.e. the nutritional value of foods. A metric that reflects the function of the food (a functional unit) is important to more accurately describe its environmental impact. In the context of this work, it is considered that the primary function of food is to nourish by providing dietary energy and nutrients to the body. Therefore, the amount of dietary energy, protein and calcium are adopted as functional units, in addition to food weight or volume. Dietary energy (kcal) and protein (g) are important for understanding food security and different forms of malnutrition, whereas calcium (mg) is an important micronutrient for bone health and several physiological functions.
This infographic shows the estimated average greenhouse gas emissions (kilograms of carbon dioxide equivalents (kg CO2 eq)), water use (litres) and land use (square meters (m2)) per 1000 kilocalories, 10 g of protein and 100 mg of calcium reported as consumed, per person per day. The calculations consider all individuals in the population: consumers and non-consumers. Consumers are those individuals who consumed the foods of interest during the survey period, and non-consumers are those who did not.
Quantities of foods reported as consumed are multiplied by the environmental impact of that given food. This is a similar approach to the one used to assess nutrient intakes using food composition data. After calculating the environmental impact per food consumed, the impacts of the entire diet are calculated by summing up all foods consumed by an individual per day. If an individual has multiple 24-hour dietary recalls/records, an average of the number of days of consumption is considered. The same procedure is applied to calculate daily per capita energy, protein or calcium intake. Finally, the population daily average environmental impact of diets per 1000 kcal, 10 g protein, or 100 mg of calcium is calculated.
The functional units used are aimed at normalising results, and are not intended to reflect dietary energy and nutrient requirements. Useful information for nutrient adequacy assessments is available in the “Advanced Analysis” infographics, which present the estimated distribution of usual intakes for selected micronutrients.
All infographics present information for three levels of environmental impact: average, low and high. The main graph is calculated using the global average environmental impact of each food, based on Poore & Nemecek (2018). Two additional graphs present hypothetical scenarios showing the environmental impact of the same diet if all foods had lower environmental impacts (low-impact scenario), or higher environmental impacts (high-impact scenario). These hypothetical scenarios reflect the variation in environmental impact values and the uncertainty around estimates using the global means (main graph). The low-impact scenario is calculated using the 10th percentile of the environmental impact of each food, based on Poore & Nemecek (2018), whereas the high-impact scenario is calculated using the 90th percentile of the environmental impact of each food. The variation of the impacts within agricultural food commodities in the Poore and Nemecek dataset (the percentiles) represents different production methods that can be more or less sustainable.
The infographics are calculated for the three levels of environmental impact, separately. No modelling is performed to derive the different scenarios.
While FAOSTAT, along with AQUASTAT, provide an overview on how agriculture contributes to greenhouse gas emissions, water use and land use in each country over time, the FAO/WHO GIFT environmental infographics provide details on the environmental impacts of diets consumed by a given population. This allows for an understanding of the environmental implications of dietary choices made by individuals, and is based on actual dietary intake data, as opposed to food supply or purchase data. FAO/WHO GIFT and FAOSTAT provide complementary information on the environmental impacts of both food production and consumption.
For further details and access to country-level statistics on emissions and land use, please refer to FAOSTAT data on Agrifood systems emissions and Land Use/Land Cover. For country-level statistics on water use, please refer to AQUASTAT.