The role of energy demand reduction in achieving net-zero in the UK: Nutrition

Alice Garvey and Jonathan Norman

Background

The CCC estimates that 11% of UK GHG emissions are attributable to agriculture and land use, and predict that the sector will become a major emitter in 2050 (based on 2016 data; p. 12, CCC, 2018). The food and drink industry also represents 7% of the UK’s industrial GHG emissions (Hammond, 2018). As the ultimate driver of agricultural and related emissions, we consider how changes to the quantity and type of food demand could contribute to UK low energy demand pathway by 2050. This analysis adopts the framework of ‘avoid, shift, improve’ to reduce the energy demand of meeting the energy service of nutrition (Creutzig et al, 2018). We consider three key options for constraining energy demand in the sector, which cover each stage of the UK food system, and address the major current sources of inefficiency and emissions-intensity. The food system presents particular challenges in considering energy demand, given that non-energy emissions are more significant in the sector, relating to land use change (LUC) and livestock (ruminant enteric fermentation).

As strategies to ‘avoid’ energy demand, we consider the effect of calorific intakes being brought in line with Government Dietary Recommendations (i.e. healthy levels), and in reducing supply chain food waste. Calorific intake is the determinant of the volume of food demand per capita. The UK is challenged by overconsumption, with approximately 65% of the population of England estimated to be in ‘overweight’ or ‘obese’ BMI groups as of 2017 (NHS Digital, 2018).

Ensuring calorific intake is at guideline levels would reduce food demand, whilst promoting several socioeconomic co-benefits such as improved health outcomes, reduced cost of household food expenditure, and lower costs associated with the disease burden for public services.

Reducing food waste and losses across the supply chain is a key public policy target, as cited in the recent Resources and Waste Strategy (HM Government, 2018). It is also a means of avoiding additional food demand, by making more efficient use of the food that is currently delivered through the UK food system. WRAP report that the cost associated with household food waste in the UK was £14.9 bn in 2015, creating equivalent emissions of 22MtCO2e for the same year (p.4, WRAP, 2018). Minimising avoidable food waste rates across the supply chain would result in lower final food demand, as a resource efficiency improvement, as well as providing cost savings across the supply chain. In developed nations the majority of food waste occurs downstream, that is, at the consumer stage (Smith et al, 2014), whilst in developing regions refrigeration and transport technologies incur greater losses earlier in the supply chain. As Bajželj et al, (2014) indicate, food waste reduction is more effective downstream given the embodied energy demand of the product by that stage. This is therefore one of our core energy demand reduction strategies in the analysis.

As part of a strategy to ‘shift’ energy demand, we consider the role of dietary transitions to more sustainable food products. Approximately 18% of global GHG emissions are attributable to livestock production (p. 83, Stehfest et al 2009), with ruminants posing the largest single anthropogenic methane source (p. 84, ibid), and occupying 25% of global land for grazing (ibid). Additionally, projected demand for meat and dairy products is expected to double globally by 2050 (p. 491, Garnett, 2009). Meat consumption is positively correlated with affluence, with many developed nations consuming more meat than is nutritionally required (Godfray et al, 2018). Meanwhile, red meat consumption (i.e. ruminant meats such as beef and lamb) is widely associated with worse health outcomes, for instance cardiovascular and other non-communicable disease (NCDs) (Willett et al, 2019). This scenario envisages a shift to plant-based diets as an extension of the recent trend for reduced meat consumption. From 2014 to 2018, the number of vegans in the UK is reported to have increased by 450,000 (The Vegan Society, 2019). Of this number, 42% of vegans were reported to have switched to this diet during 2018 (ibid).

To ‘improve’ the energy demand associated with the UK food system, we consider the potential for greater agricultural and industrial efficiency, primarily through new or best practice technologies. The BEIS Updated Energy and Emissions Projections indicated that there had been marginal change in emissions (CO2 only) in the agricultural sector between 1990 and 2016 (Annex C: Carbon dioxide emissions by IPCC category, BEIS, 2019). However, in the industrial food system there were reductions of 50% in CO2 emissions (ibid). This correlates with the Roadmaps, which indicate that there have been large reductions in the food and drink processing sector since 1990 (CO2 emissions) due to decreasing use of fossil fuels and a fairly constant trend in electricity consumption (DECC and BEIS, 2015a). There are therefore some remaining efficiency opportunities with implementation of technologies such as anaerobic digestion, improved packaging and refrigerant use (Audsley et al 2010).

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