Food waste as an environmental pollutant

Background

To what extent does German food waste pollute the environment? And how much must greenhouse gases be reduced so that we can meet the United Nations‘ goal of halving the per capita food waste at the retail and consumer levels by 2030?


In order to answer these questions, the Thünen Institute of Rural Studies developed an ecological model for the entire German food sector within the framework of the joint project REFOWAS. This model makes it possible to calculate the environmental impacts of various foodstuffs consumed in Germany. The calculation includes the total life cycle of a product, beginning with the raw product production. In addition to domestic products, imported and exported foodstuffs as well as waste in the entire value added chain are considered.

The model comprises twelve product groups which together cover all significant food areas:

  1. Meat and meat products
  2. Eggs and egg products
  3. Milk and dairy products
  4. Cereals and grain products
  5. Potatoes and potato products
  6. Other foodstuffs (such as spices, sauces, etc.)
  7. Oils and fats
  8. Sugar and sweets
  9. Vegetables and vegetable products
  10. Fruits and fruit products
  11. Fish and fish products
  12. Beverages (tap water, soda, coffee, tea, alcoholic beverages, etc.)

Calculating the environmental impact:

Currently, environmental impacts are evaluated at three impact levels: land occupation (agricultural), greenhouse gas emissions, and the cumulative energy demand.

The impact category “agricultural land occupation” comprises all areas necessary for food crops including some feedstuffs. The greater the value in the land use, the more agricultural area is required for these foodstuffs. The areas are thus no longer available for other uses (for example, resettlement, recreation, natural protection areas.) The land use is calculated in the unit hectare and annum (ha*a).

Greenhouse Gas Emissions (GHG) result from various processes and include gaseous emissions (i.e., in the combustion of fuels in agricultural machinery or in the microbial decomposition of organic substances). The more GHG released during the production of a foodstuff, the greater the environmental damage to our climate. GHG are expressed in the unit Carbon Dioxide Equivalents (CO2-eq).

All energy resources (i.e., fuels required for the production of a foodstuff) are considered in the calculation of the “Cumulative Energy Demand” (CED). The extraction and processing of fuels like coal, natural gas and petroleum have many negative impacts on the environment (i.e., mining). The higher the CED, the more energy must be released and thus the negative consequences for the environment increase. The measurement unit for CED is the Gigajoule (GJ).

The ecological balance model measures the following factors:

Greenhouse gas emissions per kilogram food

 

 

The chart shows all of the greenhouse gas emissions in food production and processing for individual products and sectors. The shown values are related to one kilogram of an agricultural raw product (farm gate), and then for the finished, prepared foods (consumption).

Thus the product group cereals, for example, also contains processed products like bread. Meat production and processing cause high to very high stress for the environment. Many beverages are comprised largely of sugar and/or water, meaning that the original product (for example, pure juices) cause more environmental stress per kilogram than the final product. Potatoes cause relatively little stress in production, but the processing (i.e., frying) has a large impact on the environment.

Impact of the German food consumption on the environment

 

 

A total area of 38 million hectares agricultural land is used annually for the production of foodstuffs consumed in Germany. At the same time, the German food sector releases about 177 million tons of CO2-equivalents and requires an energy consumption of 3.7 billion gigajoules for all activities.

Impact of food waste reduction on the environment

 

 

Germany has committed itself to reducing half the food waste per capita at the retail and consumer levels by 2030. If this target is achieved, the greenhouse gas emissions could theoretically be reduced by nine percent in comparison to the current level (see the yellow column in the chart above).

A constant level of consumption is assumed in the modelling of reduction scenarios – with all levels of the value production chain featuring a reduced waste level.

The results are in accordance with the largest possible level of savings through avoided food waste. Environmental impacts of the prevention strategies, rebound effects or other methods are not considered here. However, the entire value added chain is considered, from production through processing through to consumption.

The findings from the environmental assessment are incorporated into our recommendations, which are published in specialist journals (Sustainability article in English available).