Biodiversity – how can we include it in environmental life cycle assessments of products?

SOLID, WP4 is working on improving the environmental life cycle assess-ment (LCA) of dairy production – e.g. including the effect of soil carbon changes and on biodiversity. Using a new approach to include biodiversity in LCA of dairy systems in three European countries indicated that a high share of grassland in the dairy systems reduced biodiversity losses accu-mulated over the entire chain.

By Marie Trydeman Knudsen, John E. Hermansen, Aarhus University, Peter Dennis, Aberystwyth University & Matteo Guerci, University of Milan, WP4

European dairy production affects the environment in various ways such as climate change, nutrient leaching etc. Life cycle assessment is a method used to assess the environmental impact of e.g. a litre of milk or a kg of cheese.

Life cycle assessments are for example used to calculate the carbon footprint that can be found as a carbon label on some products in Europe. However, the carbon footprint only documents the effect on climate change. But other environmental impact categories are also important, such as eutrophication and biodiversity. In order not to underestimate impacts when evaluating different systems, various environmental impact categories needs
to be included. However, the problem with biodiversity is that it is very hard to estimate – especially in a life cycle assessment when the aim is to accumulate the effect over the entire chain and document it e.g. per litre of milk.

The ‘European Food Sustainable Consumption and Production Round Table’ (Food SCP) acknowledges the importance of biodiversity on the political agenda and in the environmental impact assessment of food and drinks products, but it considers that more scientific research is needed to be able to quantify properly the impact of food and drink products on biodiversity.

A new approach for biodiversity was applied, studying dairy production systems in three European countries 
An approach to estimate the effect on biodiversity in different agricultural systems was suggested in a recent paper from the UK. The basic idea is to compare the biodiversity loss (potentially disappeared fraction of plant species) of the actual land cover (e.g. arable land, grasslands etc.) to a baseline of semi-natural forest. It is assumed that losses in plant diversity reflect losses in biodiversity in general. Based on the different types of land covers in dairy systems, an overall biodiversity loss can be calculated. The biodiversity loss of organic arable land is e.g. 0.36 – meaning that 36% of the plant species richness in the baseline is potentially lost, when we cultivate the land with organic arable crops. Whereas the biodiversity loss in organic grassland compared to the baseline is 0 – meaning the nothing is lost and the species richness is the same. An overall biodiversity loss of a dairy system can be calculated by combining the biodiversity loss for the different types of land covers in the dairy systems.

We tested this approach when making life cycle assessments of dairy systems in three European countries. The biodiversity loss of the dairy systems were divided by the amount of milk produced in the system – as we normally do in life cycle assessment – to get an estimate of biodiversity loss per kg of energy corrected milk (ECM). The preliminary results indicated that a high share of grassland in the dairy systems seems to reduce both the carbon footprint of milk and the biodiversity loss (Figure 1).

Figure 1. Biodiversity loss kg-1 ECM (energy corrected milk) and carbon footprint (kg CO2 eq. kg-1 ECM) as affected by the share of grassland in different dairy systems in three countries in Europe. The twelve different dairy systems are each represented by a dot in the graph.
Figure 1. Biodiversity loss kg-1 ECM (energy corrected milk) and carbon footprint (kg CO2 eq. kg-1 ECM) as affected by the share of grassland in different dairy systems in three countries in Europe. The twelve different dairy systems are each represented by a dot in the graph.

The biodiversity loss was lower with a high share of grasslands because the plant species richness is higher in grasslands than arable land. The lower carbon footprint of milk in systems with a high share of grasslands was due to a greater carbon sequestration in
grasslands compared to arable land and less energy requirements for tillage and sowing.

Validating the approach with BioBio data from other European countries
The basic data for biodiversity loss in different types of land covers was based on data from the UK. However, it is important to test whether this relationship is consistent with data from the rest of Europe. Therefore, data on plant species richness of different types of
land covers in different European countries from the BioBio project will be used to validate the approach and estimate biodiversity losses from the different types of land covers in Europe. Furthermore, the approach might need to be refined to include more agricultural land covers in Europe. Finally, the assumption, that losses in plant diversity reflect losses
in biodiversity in general, will be tested by assessing if the relationship revealed for plant species is consistent with that experienced by other organisms, such as invertebrates.