This article by T.C. Ponsioen of Wageningen University, and H.M.G. van der Werf of INRA, discusses the major sources of inconsistency in life cycle assessment (LCA) analyses of food and drink, and makes recommendations to address these inconsistencies. The article begins by describing the many attempts that have been made to standardise (or ‘harmonise’) environmental footprints of food and drink, and identifies five main areas which lack consensus.
These areas are (quoted directly from the article):
- How to allocate deforestation to land use activities;
- how to assess agricultural emissions profiles;
- how to make regionalized water scarcity assessments;
- how to choose the functional unit of food and beverages; and
- how to deal with multi-functional processes in agro-industry.
The main body of the article tackles each of these questions in turn, detailing the reasons for the lack of consensus on each topic and setting out the authors’ recommendations for addressing them:
Regarding deforestation: the authors identify the issue as being that deforestation, or more generally land transformation, is not clearly linked to specific agricultural activities, and is therefore not directly attributable to specific agricultural products. Having outlined some opposing methods for addressing this issue, the article proposes a compromise whereby the CO2 emissions associated with the deforestation in a country over the last 20 years are allocated proportionally to agricultural activities that have increased over the same period. E.g. if soybean production accounts for 60% of the increased cropping area in Brazil over the past 20 years, then 60% of Brazil’s deforestation-associated CO2 emissions are attributed to soybeans.
Regarding agricultural emissions: the authors explain that emissions resulting from biological processes (such as the breakdown of agrochemicals, the release of heavy metals and production of gaseous by-products of agricultural activities) are very difficult to measure or calculate accurately. They state that for many of these types of emissions, models exist of varying levels of complexity (with models of greater complexity tending to report higher emissions, since they take account of more indirect emissions), and recommended that intermediately detailed models should be used as standard. However, their justification for this recommendation is not entirely clear.
Regarding regionalised water scarcity: the authors note a need for water scarcity data to be available at a more regionalised level, citing software and methodological limitations as the main barrier to this goal. They argue that available country-level data (e.g. on evapotranspiration rates) are not sufficiently detailed to facilitate management at a farm level. They therefore recommend a targeted improvement of the available technology and methods to allow for the collection and processing of relevant data at this smaller-scale level.
Regarding functional units: the authors explain that the most common functional units used for food and drink revolve around mass or volume (e.g. CO2 emissions per 100g of product), but that this does not really capture the various parameters of nutrition and other beneficial outputs derived from a food product. The authors suggest that a more meaningful functional unit for food and drink products would be economic value, specifically price at retail, as this, in theory, reflects the value placed on a product by consumers which, again in theory, should encapsulate the benefits (nutritional and subjective) derived from the product. However, the authors do not address the well-known disparities between the real value (including health and environmental externalities) and the retail price of many products (or the artificial highness or lowness of prices due to products being used as loss-leaders or having a large mark-up). Nor do they thoroughly address the idea of nutrition-oriented functional units (see for example this discussion on using nutrient density indices in relation to climate impact).
And finally regarding multi-functional processes: similarly to the problems with defining functional units, the authors highlight the difficulties of apportioning impacts to products which have alternative competing uses (e.g. wheat grain and wheat straw). They again recommend an economics-based allocation, their justification being that it is economics that determines which functional product is favoured.
The article arguably does a better job of expounding the complexity of the issues involved in defining the scope of an LCA concerned with food or drink, than it does of proposing solutions or concrete recommendations for addressing this complexity. While the recommendations seem largely reasonable, the authors arguably make little attempt to thoroughly critique and justify their suggestions, which may limit the impact of this work.
Several attempts have been made to harmonize guidelines for environmental footprints of food and beverages. For example, the food Sustainable Consumption and Production Roundtable, the Leap partnership, and the Environmental Footprint project, in particular within the Cattle Model Working Group. Despite all these activities, there are still many issues unresolved. This paper gives an overview of five important reasons why it is so difficult to reach consensus within the sector. In short, the issues are: 1) how to allocate deforestation to land use activities; 2) how to assess agricultural emissions profiles; 3) how to make regionalized water scarcity assessments; 4) how to choose the functional unit of food and beverages; and 5) how to deal with multi-functional processes in agro-industry. Recommendations as motivated in this paper are, in summary, to: 1) use the method to calculate the amount of land use change caused by increased pressure from growing areas per crop in each country; 2) always calculate agricultural emissions using at least an intermediate level of detail with the option to add more detail; 3) use good quality irrigation and crop evapotranspiration data, and at least country specific water scarcity factors; 4) report the environmental footprint results per unit of economic value besides per unit of mass or volume to enable fairer comparisons; 5) and apply economic allocation in all multi-functional agricultural and agri-industrial processes based on realistic prices calculated as multiple year averages.
Ponsioen, T.C. and van der Werf, H.M.G. (2017). Five propositions to harmonize environmental footprints of food and beverages. Journal of Cleaner Production. [Article in Press] http://dx.doi.org/10.1016/j.jclepro.2017.01.131
Read the full article here.
08 Feb 2017
Post a new comment »