Environmental Gains From Individual Dietary Change Are Both Possible And Significant

Most animal advocates know that consumer choices surrounding food can lead to significant reductions in food-related GHG emissions. In this study, researchers from Lancaster University, U.K. used statistics on greenhouse gas (GHG) emissions associated with different foods and self-reported dietary information of citizens to show just how much their choices can affect emissions. Different scenarios were analyzed, ranging from eliminating meat from the diet, changing to eating meat of less carbon-intensive animals, cutting out food waste, not eating foods grown in hot-houses or air-freighted to the U.K., to avoiding packaging. The conclusion: different combinations of consumer actions can easily lead to reductions of 25%. Should the entire U.K. population reach this milestone, it would equate to a 71% reduction in the exhaust pipe CO₂ emissions from the entire U.K. passenger car fleet.

The scientists start off by reminding us that international agreements have been in place with the aim of stabilizing and eventually reducing the emission rates of GHGs ever since 1992. However, in some sectors and particularly in agriculture, where there are very significant indirect sources of GHGs (for example, due to land use change), it is still very difficult to measure GHG emissions precisely and reduce them effectively. While difficult to trace, emissions from the global production of meat alone are estimated to be responsible for 15–24% of global GHG emissions. The researchers note that these include direct emissions through the combustion of fossil fuels on farms, methane emissions from ruminants, nitrous oxide emissions from fertilizer application, and indirect emissions, mainly via land use change.

The food sector is one in which immediate effective action is possible, unlike power generation or transport, where infrastructure has a turnover timescale of decades. The study included estimating an average population food consumption, which was adjusted for food lost and wasted through the supply chain and in consumer homes. The former, as indicated by previous research, is thought to comprise a staggering 30-50% of the total food produced globally. The average consumption also includes accounting for the typical underreporting of food intake in self-reporting surveys of 20%. Meanwhile, the food-related emissions included factors from production to the farm gate, transport from farm to processing and/or distribution centers, processing, packaging, storage and supermarket operations. The emission factors for production of beef and dairy, for example, also include an allocation for deforestation.

The researchers found that eliminating meat from the diet reduces food-related GHG emissions by 35%, a realistic option already adopted by millions of vegetarians. The good news is that it can be partially adopted with partial emissions benefits to be achieved. The study also found that this option includes small cost savings (3%). Furthermore, by shifting consumption from more carbon-intensive meat, such as that of cows and sheep, to less carbon-intensive meat, such as that of pigs and birds, an 18% reduction in total emissions could be achieved.

Breaking the numbers down more, cutting out all avoidable waste delivers a smaller saving of 12%. This action is quite straightforward and offers clear co-benefits that should surely interest most consumers. Eliminating hot-housing and air-freighting offers a further 5% reduction in emissions. The researchers inform that his may be a relatively difficult action for individual consumers to implement, though, mainly due to the lack of available information on the transportation and growing practices of food. The total elimination of packaging is neither possible nor necessarily desirable (food preservation prevents waste) and delivers just 3% emissions savings. Nevertheless partial implementation of this action could be relatively easy for many.

In one modeled scenario, a 15% reduction in meat was combined with a shift to pig and bird meat, 50% less waste and 15% less packaging, but no change to air-freighted and hot-housed produce, and resulted in savings of approximately 25%. Meanwhile, the calculations demonstrate that even with the maximum possible reductions in waste, packaging and air-freighting, a scenario in which diet itself is not changed makes achieving a 25% food GHG reduction impossible. In contrast, while the scenarios modeled in this study provide a means of achieving 25% reductions, the maximum combined impact of all proposed actions is an impressive 53%.

Although the researchers confirm that there are further emission reductions achievable than those covered in this study, such as reducing over-consumption, waste of dairy products and raising awareness about the emissions behind different foods, the take home message is pretty clear: change on individual levels is both possible and significant. Furthermore, it is clear that food retailers can do a lot to enable and support such mitigation actions by: ensuring that the information on these simple guidelines is readily available and made easily understandable for the consumer; ensuring that less carbon-intensive options are available for purchase, are made to look appetizing and are promoted; and encouraging consumers to buy only what they will eat.

The study highlights some important possibilities that are applicable across the board: everyone from meat eaters to veg*ns should be aware of the environmental impacts their purchases have. Although the particular results presented here are U.K.-specific, discussions should be promoted and information spread globally to tackle the ever-growing carbon footprint of what we eat. Animal advocates reading this will surely feel further supported in the promotion of incremental, sustainable dietary change towards plant-based nutrition, as the positive environmental effects of such changes are clearly significant.