20 August 2024

Leading the way with LCA

Research at the Horticulture Development Department in Ashtown is examining the environmental impact of fruit and vegetables grown with biostimulant inputs and packaged with different packaging forms.

Lael Walsh and Éamonn Walsh are part of the team examining how Life Cycle Assessments can provide a more nuanced view of horticultural impacts. Photo credit: Iain White, Maxwell Photography

Businesses and farms in the food and agriculture sector, all along the value chain, are searching for tools to help them understand the impact of their product on the environment. Producers recognise the importance of reducing environmental emissions and creating a more sustainable food system, but also identifying the critical impact areas where these reductions can be made. Simultaneously, there is pressure in the policy environment to address these issues. But how do we go about achieving this change?

“More and more farms are looking to assure their sustainability going into the future and are exploring different options to assess their current state and progress,” explains Éamonn Walsh, a postdoctoral researcher at Teagasc Ashtown.

“A base assessment of environmental impact is important as a first step in understanding where to make changes to improve the sustainability of a food product. Life Cycle Assessment – LCA – is a tool which can be used to assess the environmental impact of a specific product’s life cycle. It can be restricted to particular parts of a life cycle – just the farm for example – or it can extend to the whole life cycle, including pre-production, processing, packaging, transport, storage and retail.”

A range of impacts

LCA is an iterative process of data collection and emissions calculations. At the start, the scope of the LCA is set by determining the boundaries of what will or will not be included in the calculations. Based on that boundary, data is collected directly from stakeholders or from existing databases, such as Ecoinvent, Agri-footprint or Agribalyse. Many databases are behind a paywall, but some are free to access, for example, Agribalyse and Environmental Footprint from the EU. These collected values are then used with emission factors for specific substances, CO2 for example, to calculate environmental emissions. LCA practitioners can use free (openLCA) or paid (SimaPro) software programs to calculate emissions.

“LCA can model the environmental impact in a range of categories, providing insight into not just greenhouse gas emissions, but other notable impacts like eutrophication, terrestrial and marine acidification, human toxicity, and resource and water scarcity,” Éamonn continues.

“The range of impact categories broadens the focus beyond greenhouse gas emissions, which, while important for climate change, do not provide a rounded assessment of environmental impact.”

Screen greens

LCA is now frequently utilised in the agriculture and food industries. In the Leaf No Waste project, funded through the Future Innovator Prize Programme from Science Foundation Ireland, LCA is being used to identify emissions hotspots and assess sustainable interventions in important Irish-grown horticulture crops such as mushrooms, strawberries and leafy greens.

Presently, LCA is being used to build a scenario for each crop as it is currently produced and packaged. With the basic scenario generated, the use of novel treatments and packaging can be built on top of this. For example, an LCA has recently been published assessing how a change in shelf life through the use of a silicon biostimulant during production, together with a novel packaging film, affects the environmental impact of spinach.

This spinach LCA showed that an assessment of shelf life is not as straightforward as it seems, explains the study’s author, Research Officer Lael Walsh.

“One could easily assume that a longer shelf life would always be more sustainable or that a compostable film is usually preferrable. However, the energy use from refrigeration during this extended shelf life must also be taken account of, as well as the changes to the amount of waste food being generated during this storage. An LCA can tease out the balance of inputs and outputs in a specific scenario to determine how the use of a new technology may increase or decrease emissions.”

Finding hotspots

What kind of a benefit could a business or farmer expect from an LCA? An LCA identifies the emissions hotspots in the production of an agricultural product, allowing for initial judgement of what process elements require most focus. Furthermore, an LCA can help identify whether emissions hotspots are in parts of the life cycle under direct control of the business. For example, if an emission hotspot is a product input used in cultivation there is a possibility to change that.

Aiduan Borrion, Professor at University College London and advisor to the project, explains: “Any business or farm looking to undertake this process will have to create an inventory of data containing values for all the inputs and outputs associated with a specific agricultural product. Most of this data can be straightforwardly collected, but it does require some effort on behalf of the business to make sure it is an accurate representation of the real-life farm or site.”

In the horticulture sector, this includes data on inputs like growing media, fertilisers, transport, electricity, heat generation, gaseous emissions and waste recycling.

Context clues

One of the main challenges in undertaking an LCA is the interpretation of the results. The results cannot be understood in isolation, but must be assessed in the context of the methodology. This is especially true when comparing values from other studies, as methodology can have a significant impact on the results, explains Lael.

“A prime example of this is the system boundary of the study. Some studies will set the boundary from the cradle to farm-gate, whereas others will set the boundary later in the life cycle, e.g. the cradle to retail-stage, which includes emissions post production such as transport, packaging and cold-storage.”

Other methodological choices, like the allocation of emissions between different but connected production systems, should be done following the ISO standards to maintain consistency. Finally, many assumptions will have been used in the LCA, which should be clearly stated. Despite these caveats, an LCA generates results that can act as a useful guide for decision-makers in the horticulture sector.

FUNDING

This research forms part of the Leaf No Waste project, funded by SFI grant number 20/FIP/FD/8934P awarded to Technological University Dublin and Teagasc.

Acknowledgements

The contributors wish to acknowledge the collaboration with Lorraine Foley and Jesus Frias at Technological University Dublin in this project.

Contributors

Éamonn Walsh, Postdoctoral Researcher, Teagasc Food Research Centre, Ashtown.

Aiduan Borrion, Professor of Environmental Engineering, University College London.

Lael Walsh, Research Officer, Teagasc Food Research Centre, Ashtown.
lael.walsh@teagasc.ie