Calculating the environmental footprint of a product

Life Cycle Assessment (LCA) is a research method for evaluating the environmental impact of a product throughout its entire life cycle. An LCA assesses all the stages in the production, marketing and use of a product, from raw materials, packaging and transport to retail, consumption and waste processing (cradle-to-grave). Multiple environmental impact categories are captured, such as climate change, eutrophication, acidification, water use and land use. An LCA reveals the environmental impacts and where they occur in the life cycle of a product (hot-spots).

Carbon footprint of soy

Soybean is an important source of protein for both feed and food products, and its global demand is rising steadily. It is an efficient crop that needs relatively few inputs as it is able to fix nitrogen from the atmosphere. However, the expanding area under soybean cultivation raises environmental concerns because much of this is in tropical areas where it is a driver of deforestation.

When forests are cleared to make way for farming, the carbon that was stored in the trees is released into the atmosphere as carbon dioxide. Such emissions resulting from land use change (LUC) also need to be accounted for in LCA. This is not a straightforward exercise as appropriate data are often lacking. In an ideal situation, information from satellite imagery or other sources would be used to determine the exact historic land use of a certain area (over the past 20 years). However, such data are often not available, for example because the exact locations of cultivated areas are not known, and so other methods have to be employed. The PAS 2050 standard method for calculating a product’s carbon footprint provides guidance on how to do this.

Based on country-level statistics on the expansion or regression of cropland and forest area, deforestation is assigned to crops with high relative expansion. The European Commission adopted the PAS 2050-1 LUC method and made it a requirement for Product Environmental Footprint (PEF) calculations.

Based on this methodology, Blonk Consultants has developed a tool that calculates LUC for each country–crop combination. This LUC is also integrated into Blonk Consultants’ Agri-footprint database, the most extensive LCA database on agricultural and food products. The figure on the right shows the carbon footprint of soy for several key soy producing countries, as derived from the Agri-footprint database. It clearly shows that in many cases LUC is responsible for the lion’s share of the crop’s carbon footprint. This high footprint is also reflected when looking at products in which soy is used.

Figure 3 shows the contribution made by soy, in the form of soybean meal for animal feed, to the overall footprint of animal products. In this case, the Dutch market mix of soybean meal is used which mainly comprises soy from Brazil and Argentina.

Some considerations: Strengths and weaknesses of LCA of soybean

Even though the carbon footprint (also referred to as climate change or global warming impact) is by far the most well-known impact category, LCA goes much further than that. It includes many other categories that capture significant environmental issues, such as water consumption, fine particulate matter formation, acidification and eutrophication. This generates a complete picture of the impact of a product or process on the environment and allows for a balanced comparison of the environmental impact of different products. It is possible to aggregate several of these environmental impact categories (into so-called endpoint categories, such as biodiversity), to get a complete overview of the environmental impact. However, it should be borne in mind that LCA can only provide an approximation of the environmental impact, and is only as good as the data that used. Detailed and accurate data will result in robust impact results, but where data are lacking assumptions must be made (e.g. using background data or estimations), which affects the quality of the results. Despite the many impact categories to choose from in LCA, not all environmental issues are yet covered, such as soil degradation. Reduced inputs of mineral or organic fertilisers would lead to a low footprint, however the resulting depletion of soil nutrients would be unaccounted for. Soybean cultivation is most efficient in tropical regions. The high carbon footprint of soy production in these regions could lead to expansion of soy cultivation into areas that are less suitable for soy or to the cultivation of alternative crops that are less efficient.