When we cannot see everything, we see nothing
People often believe that the environmental impact of yoghurts comes from packaging or milk processing. In fact, yoghurts' environmental impact is mainly linked to milk production and especially cow's diet.
Approximately 70 % of the environmental impact of yoghurt comes from milk production. If we look closely at fresh milk production impact, two-thirds are linked to cows' diet and their methane emissions (a greenhouse gas 28 times more impactful than CO2 over a 100-year period).
The two factors are closely linked, Thus, controlling cows' feed impact is a very effective way to reduce yoghurts' environmental footprint.
The conclusions of Glimpact's analysis, carried out according to the PEF method (adopted by the EC), are based on data from a representative sample of commonly observed products. Therefore, they do not take into account the specificities of production conditions or means of production.
We usually believe that packaging or manufacturing are yoghurts' main impact sources. In fact, milk production is the major source of environmental impact.
According to the PEF method adopted by the EC, the environmental impact should take into account 16 impact categories. It is defined by a score that aggregates the different results obtained for each impact by normalisation and weighting. This score is expressed in points (Pt) on a continuous scale, it allows products to be compared with each other.
About 70 % of yoghurts' (packed in polystyrene pots) environmental footprint comes from milk production.
Methane emissions come from "enteric fermentation", the digestive process of cows, and more generally of ruminants. The two main sources of fresh milk production impact are cows' diets (30 %) and cows' methane emissions (33 %). On-farm consumption and emissions (energy, water, nitrous oxide from manure, etc.) account for less than 30% of fresh milk production environmental impact.
Some feeds reduce stomachs fermentation, allowing cattle to emit less methane. Studies have shown that the use of flaxseed or a supplemented oilseed diet can significantly reduce methane emissions from cattle by 10 to 30%.
Therefore, farmers and industrials can act on cow's diet to reduce their impact. At your level, you can still choose your yoghurts according to their packaging but it is not the impact main source.
We will now compare 3 types of yoghurt pots: plastic, cardboard and glass (one-way and returnable).
Pots considered are the following: 4 gram polystyrene (PS) plastic pot, 10 gram cardboard pot and 133 gram glass pot. For returnable yoghurt pots, 350 km by truck, 39 km by train and 87 km by barge are considered for the return to the washing site. Pot and lid/cap weight and transport data were defined in the PEFCR Dairy products an EC evaluation reference.
Yogurt sold in a non-returnable glass pot has about twice the impact of yogurt sold in a cardboard or plastic pot.
If returned and reused enough times (on average 17 times), the glass pot sees its environmental performance clearly improved (by about 35%). However, it remains 16% more impactful than a yoghurt in a paper pot and 13% more impactful than one in a plastic pot. Also note that after a certain number of rotations, the environmental gain becomes very small.
The environmental impact calculated does not take into account the use phase (refrigerated storage of the consumer, cooking, washing of utensils and dishes required for preparation). The results were reported per SKU.
