This paper explores how far changes in consumers’ diets can lead to reductions in food related GHG emissions. While previous studies have looked at the relative mitigation impact of switching to vegetarian and vegan diets, this paper estimates the contribution that the average UK diet makes to GHG emissions. It does so by combining the GHG emissions from 66 different food categories with self-reported dietary information. The average GHG impact that the authors arrive at is 8.8 kg CO2 eq per person – including both food eaten and the embedded emissions in food wasted (post-purchase).
The paper finds that by far the largest potential reductions are achieved by eliminating meat from the diet (35% reduction), followed by changing from carbon-intensive lamb and beef to less carbon-intensive pork and chicken (18% reduction). But valuable savings may also be achieved by eliminating avoidable waste (12% reduction); not eating foods grown in hot-houses or air-freighted to the UK (5% reduction) and smaller savings from reducing packaging (maximum 3% reduction though complete elimination of consumer packaging is likely to lead to higher levels of wastage).
The paper illustrates how, by combining different actions and levels of action, annual reductions of 25% in food related GHG emissions may be achieved. If such changes were adopted by the entire UK population this would be equivalent to a 71% reduction in the exhaust pipe emissions of CO2 from the entire UK passenger car fleet.
The greenhouse gas (GHG) emissions embodied in 66 different food categories together with self-reported dietary information are used to show how consumer choices surrounding food might lead to reductions in food-related GHG emissions. The current UK-average diet is found to embody 8.8 kg CO2e person−1 day−1. This figure includes both food eaten and food wasted (post-purchase). By far the largest potential reduction in GHG emissions is achieved by eliminating meat from the diet (35% reduction), followed by changing from carbon-intensive lamb and beef to less carbon-intensive pork and chicken (18% reduction). Cutting out all avoidable waste delivers an emissions saving of 12%. Not eating foods grown in hot-houses or air-freighted to the UK offers a 5% reduction in emissions. We show how combinations of consumer actions can easily lead to reductions of 25% in food related GHG emissions. If such changes were adopted by the entire UK population this would be equivalent to a 71% reduction in the exhaust pipe emissions of CO2 from the entire UK passenger car fleet (which totalled 71 Mt CO2e year−1 in 2009).
C. Hoolohan, M. Berners-Lee, J. McKinstry-West, C.N. Hewitt, Mitigating the greenhouse gas emissions embodied in food through realistic consumer choices, Energy Policy, Available online 1 October 2013, ISSN 0301-4215
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There are a number of studies on the GHG mitigation potential achievable through different dietary patterns on the FCRN website: try searching in the ‘consumption’ category of the research library or doing a general search on ‘sustainable diets’. Have a look in particular at the Livewell reports here and here.