In the end of September, a workshop on the topic of practical sustainability assessment for dairy producers was held in the UK. It provided an opportunity to gather feedback from farmers, consultants and stakeholders on the current SOLID results on this topic.

By Laurence Smith, Sustainability Researcher, The Organic Research Centre, Elm Farm (ORC)

On the 24^th September 2014 a workshop was held at The Organic Research Centre, Elm Farm on the topic of practical sustainability assessment for dairy producers.  The workshop provided an opportunity to gather feedback from farmers, consultants and other industry stakeholders on the results from the sustainability assessments and methodology development carried out within workpackage 4 to date. The day also presented the opportunity to try out some of the most popular carbon footprinting tools currently available.

John Hermansen of Aarhus University began by providing an overview of the SOLID project and workpackage 4, highlighting the outputs for industry (e.g. a toolbox for sustainability assessments) and policy makers (e.g. dairy system comparisons). Laurence Smith of ORC then provided an overview of the different methods used to calculate carbon footprints of farming systems and the online carbon footprinting tools currently available.  The results from the assessment of 34 organic dairy farms were then presented by Sanna Hietala of MTT.  The assessment showed that higher milk yields resulted in lower carbon footprints per litre of milk across the countries assessed.

The participants were then asked to complete a practical exercise with two carbon footprinting tools, using example farm data provided by ORC.  The tools used were CALM (Carbon Accounting for Land Managers), a whole-farm assessment tool that accounts mainly for emissions within the farm gate, and the Cool Farm Tool, a Life Cycle Assessment (LCA) tool that assesses greenhouse gas emissions per unit of agricultural product(s) and includes all emissions associated with the supply chain.

Following the exercise, the differences between the methods used within both assessment tools became clear. When comparing the results of the example farms Dairy Farm 4 had a negative carbon balance within the CALM tool (i.e. net carbon sequestration overall) due to the amount of woodland, whereas the same farm had the highest carbon footprint per litre of milk within the Cool Farm Tool as a result of the low milk yield (see Table 1).  Conversely, Farm 1 had a low carbon footprint when assessed with the Cool Farm Tool, due to a higher milk yield, and one of the highest footprints when assessed with CALM, due to high rate of diesel and electricity use.

Table 1: Carbon footprint results calculated for the example farms using CALM and the Cool Farm Tool:

The exercise highlighted the importance of the method used and the unit of comparison used when assessing the carbon footprint of farming systems.  The overall message was that the best approach is to use the same tool each year to monitor long term change due to wide differences in the results between the tools. At the workshop, most of the participants preferred the Cool Farm Tool as it was found to be easier to use and interpret the results, although the fact that sequestration can be more easily incorporated within CALM was appreciated (see Table 2).  For both tools the lack of benchmark data was felt to be a drawback as this makes it difficult to assess farm performance.

In the afternoon session, Marie Trydeman Knudsen of Aarhus University presented an overview of methods for assessing biodiversity and soil C within an LCA framework. The biodiversity assessment method that has been applied calculates a biodiversity loss index for production systems through the application of a Potentially Disappeared Fraction (PDF) coefficient which is calculated in accordance with a method described in deSchryver et al. (2010). The calculation allows for an estimate of the Biodiversity Damage Potential amount (PDF/m2 occupied for the production of 1 kg of milk which can be presented alongside the results from ‘standard’ LCAs (e.g. the total GHG emissions per kg of milk).   The method for incorporating soil carbon sequestration within an LCA framework was also presented in the afternoon. The method suggested is an adaptation of the decay curves used within the Bern Carbon Cycle model, which represent the non-linear accumulation of soil organic carbon over a 100 year time-frame, following the addition of organic material. Both methods were well received by the participants. It was appreciated that calculation of the indicator for biodiversity loss and carbon sequestration at a specific farm did basically not require more data than is typically needed for an LCA of a dairy system, although some commented that the economic dimension is of primary importance for most farmers and it would be helpful if this element could be incorporated within the framework being developed.

Table 2: Views expressed on the strengths and weaknesses of the tools:

Overall the day provided a useful overview of the tools and methods currently available for UK dairy producers. The comments and feedback in the relation to the assessment tools and methods presented will be taken on board and considered within a task in work package 4 devoted to the production of a sustainability assessment toolbox.   A second workshop covering the same topic is planned to be held with representatives from the industry in Denmark in 2015.

The workshop organisers would like to thank the participants, the presenters and the authors of the carbon footprinting tools for their respective contributions to the day.

AUTHOR

References:

De Schryver AM, Goedkoop MJ, Leuven RSEW, Huijbregts MAJ (2010) Uncertainties in the application of the species area relationship for characterisation factors of land occupation in life cycle assessment. International Journal of Life Cycle Assessment 15: 682–691.

Carbon Accounting for Land Managers Tool – try it here.

 The Cool Farm Tool – try it here.

More pictures

New tools are under development in SOLID, transforming information on how to reduce the environmental impacts into customised, cost-effective suggestions.

By Sampsa Nisonen, WP4

The knowledge on environmental impacts of dairy farming is steadily increasing and when we seek to reduce environmental impacts of dairy farming, our decisions should be based on this knowledge. Climate change is easily the most researched impact category, followed by eutrophication and biodiversity. These impacts are very different by nature, but linked through their common origin in dairy farm activities. This means that when an action is taken to reduce one impact, it might have an effect on other impact categories as well. The effects could be either positive or negative, causing synergies or trade-offs. For example an action taken to reduce greenhouse gases could increase eutrophication or vice versa. Additionally, if cost-effective solutions are wanted, the monetary cost of the actions should be considered. If there are two actions with similar impacts but different costs, the cheaper one should take priority.

To choose an optimal set of improvement decisions all these points must be taken into account. Ideally, every relevant consequence of every pertinent action should be considered and the total achieved utility should be viewed in light of the total cost of these actions. With the optimal set of improvements, maximum utility per euro is attained.

New tools are under development in SOLID WP4, transforming research and knowledge on how to reduce the environmental impacts of dairy farms into customised, cost-effective suggestions.

To solve this optimisation problem, data from multiple sources is required. Naturally only a limited number of improvement options can be included in a practical model, so the first task is to compile a list of those actions, which have the most potential for effective reduction of environmental impacts. The list is based on the Rapid Assessment Tool constructed in WP 1 and FAO’s suggestions for sustainable agriculture. Life cycle assessments completed in WP 4 are used to calculate baseline results for the three environmental impacts investigated: climate change, eutrophication and biodiversity loss. The LCA results are complemented by data from expert interviews. The experts are asked to estimate two things: how much the environmental impacts change relative to the baseline results, when different improvement actions alter the dairy system and what the monetary costs for the improvements could be.

Bayesian networks (BN) are used as the primary modelling method and as framework for linking different types of data together. BN:s are probabilistic graphical models, which link a set of random variables together through conditional probabilities. BN:s are well suited for this type of decision support tool, because of their ability to deal with the uncertainties inherently present in the modelled system. The probabilistic nature of BN:s allows the interviewed experts to give their estimations as probability distributions that best describe their opinions and include their uncertainty as well. The final model calculates the results based on the average of these distributions. The network structure itself is useful, making it easy to model the connections between improvement actions and their consequences.

A simplified diagram of the model is presented in Figure 1. When data describing a dairy system – including typical LCA data and information on both the current and desired state of environmental improvements – is inserted into the model, it can calculate the probability distributions for different environmental impacts before and after improvements. The difference in impact is interpreted as utility or benefits and by dividing it by the expected cost we can estimate the cost-effectiveness of the chosen set of improvement decisions. Computer software can be used to automatically calculate the optimal set, which gives the greatest amount of expected utility per euro.

Climate change, eutrophication and biodiversity loss are measured in different units, which makes it difficult to compare decision that lead to reductions different impacts. If all three impact categories could be measured in same units, it would be easy to see where to focus the limited resources. Environmental valuation studies offer one way of converting different impacts to the same unit, in this case money. Another way would be to use separate tools to calculate separate results for each impact category, which could then be compared qualitatively.

The goal is to make the decision support tools available in the Internet. Currently separate tools are planned for the UK, Denmark and Finland to take regional differences into account.

AUTHOR

This workshop will provide an overview of sustainability assessment methods and the various carbon footprinting tools available for UK dairy farmers. New methods for including soil carbon changes and biodiversity indicators within sustainability assessments will also be presented.

The day will consist of a mix of practical sessions (i.e. trying out existing tools and methods), feedback sessions and speaker presentations.

Read more.. 

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).

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.

It is now clear the non-quota sectors like agriculture are being included in the reduction goals for greenhouse gas emissions. The EU road map to a competitive low carbon economy emphasize that efforts should be made to explore the possible benefits of less intensive farming systems taking into account the capacity of the farming system to sequester carbon. Likewise, the EU biodiversity strategy 2020 asks for means to halt loss of biodiversity.

Developing lifecycle methodology
For both global warming and biodiversity there is a link between what is happening at the individual farm and the resources that the farms depend upon, like imported feeds. The concept of life cycle assessment is very valuable to account for such interaction and therefore a key issue in this work is to develop and use lifecycle methodology
that particularly address the challenges and possible benefits of low input and organic dairy farming like land use requirement, carbon sequestration and biodiversity.

Performing life cycle assessment
When performing life cycle assessment a number of choices have to be taken, and several guidelines exist for doing so. For most classical impacts we adhere as much as possible to the work currently taking place in the European Food Sustainable Consumption and Production Round Table (SCP), which is supported by the food and drinks industry as well as the EU commission. We think this is important to have to best possible basis for
communication across products. However a main task for us is to expand these guidelines with impacts related to carbon sequestration in soils and biodiversity, which at the moment are not included.

Next step – test of conceptual framework
This work is going on right now, and we are confident that we can come up with a solid and well accepted methodology to take these impacts into account in an environmental  assessment. Next steps are to test our conceptual framework in a real farm situation, and to validate how such information can be used in the dairy chain in congruence with other important dimensions of corporate social responsibility methodologies and efforts.