Agriculture is one of the main sources of man-made greenhouse gases, accounting for 24 % of global emissions. This figure alone shows how great is the need for adjustment, but also the potential of the primary sector to achieve the climate targets of the Paris Agreement, to keep global warming at a level well below 2° C. The 'European Green Deal', which aims to reduce the European Union's net emissions of greenhouse gases to zero by 2050, can also only be achieved with the involvement of agriculture.

A newly published study by Augsburg scientists now paints a differentiated picture of agricultural greenhouse gas emissions. For different types of cultivation and husbandry, it determines which emissions occur at which points in food production and allocates them to the various food [products according to their source. In addition to carbon dioxide, the authors also include nitrous oxide and methane emissions and the climatic effects of land use change in their calculations. The climate impacts resulting from land use change are primarily caused by the draining of peatlands and the deforestation of rainforest areas, which are then used for the production of animal feed.

In order to illustrate the extent of this climate damage, in addition to determining emission quantities, its monetarisation, i. e. conversion into food-specific consequential costs, is also carried out. In a final step, the authors relate these consequential costs to the food prices currently observable on the market.

Significant differences between different food groups

In their publication, they prove that conventionally produced foods of animal origin, in particular, would have to become much more expensive if the climate impacts resulting from production were to be added to the price in a way that takes account of the polluter-pays principle. In fact, dairy products would have to be 91 % more expensive than they are today. Meat products would have to be as much as 146 % more expensive, including climate costs. A comparison between the different types of cultivation shows that the emission levels of organic farming are slightly lower than those of conventional production methods after adjustment for yield. However, due to the higher price of organic foods, this results in lower price premiums of 40 % for organic dairy products and 71 % for organic meat. Foods of plant origin are associated with a relatively low “climate backpack”, which is in the single digit cent range in both forms of cultivation.

"We ourselves were surprised by the big difference between the food groups investigated and the resulting mispricing of animal-based food products in particular," reports Tobias Gaugler on the results. “If these market mispricing errors were to cease to exist or at least be reduced, this would also have a major impact on the demand for food. A food that becomes significantly more expensive will also be much less in demand ", adds his co-author, Amelie Michalke.

Implications for consumers and economic policy

The current study is primarily concerned with the climate impacts resulting from the production and consumption of food. In further steps, the authors now intend to investigate further environmental impacts of agriculture, such as those resulting from the emission of reactive nitrogen compounds or the energy requirements of the agricultural sector. "In this context, we see our task as scientists primarily in providing data and information on the climate impact of food products. Both citizens as well as regulatory players can and - if I may say so with a certain normative claim of sustainability science - should align their actions on this basis," says Gaugler, in summary.

The team of authors consists of the two Augsburg industrial engineers, Maximilian Pieper (currently studying at the Technical University of Munich) and Amelie Michalke (visiting researcher at the University of Augsburg and doctoral candidate at the University of Greifswald), as well as the economist and sustainability researcher Tobias Gaugler. Tobias Gaugler works as a research assistant at the Institute for Materials Resource Management (MRM) of the Faculty of Mathematics, Natural Sciences and Technology at the University of Augsburg.

Original publication (Open Access):

Maximilian Pieper, Amelie Michalke and Tobias Gaugler: Calculation of external climate costs for food highlights inadequate pricing of animal products, Nat Commun 11 (2020)
DOI: 10.1038 / s41467-020-19474-6 Link: https://www.nature.com/articles/s41467-020-19474-6