The food system is responsible for more than a quarter of all greenhouse gas emissions, of which up to 80% are associated with livestock production.
A study by Springmann, Charles, Godfray, Rayner & Scarborough (2016) showed that health and climate change benefits will both be greater the lower the fraction of animal-sourced foods in our diets. Three quarters of all benefits occur in developing countries although the per capita impacts of dietary change would be the greatest in developing countries.
Moving to diets with fewer animal-sourced foods would have major health benefits. They project adoption of a global dietary guidelines (HGD) would result in 5.1 million avoided deaths per year and 79 million years of life saved. The equivalent figures for the vegetarian (VGT) diet are 7.3 million avoided deaths and 114 million life years saved and for the vegan (VGN) diet 8.1 million avoided deaths) and 129 million life years saved. The reduced mortality in the VGT and VGN scenarios compared with the HGD scenario was due to lower red meat consumption (1.7 million additional avoided deaths in each) and higher fruit and vegetable consumption (VGT, 0.8 million; VGN, 1.8 million additional avoided deaths).
Emissions reductions in the HGD scenario were largely attributable to reduced red meat consumption (97%) whereas reductions in red meat (85%) and poultry (15%) were responsible for lower VGT emissions, and lower consumption of red meat (76%), poultry (13%), and eggs and dairy (15%) for lower VGN emissions.
U sing the cost-of-illness approach, we estimate that the health-related cost savings of moving to the diets based on dietary guidelines (HGD) from that assumed in the REF scenario will be 735 billion US dollars per year ($735 billion⋅y−1) in 2050 with values in the range [based on uncertainties in the cost transfer method $482–987 billion. Greater savings occur with the adoption of vegetarian diets (VGT, $973 billion) and vegan diets ($1,067 billion). As a percentage of expected world gross domestic product (GDP) in 2050, these savings amount to 2.3% (1.5–3.1%) for HGD diets, 3.0% (2.0–4.0%) for VGT diets, and 3.3% (2.2–4.4%) for VGN diets
In conclusion, their analysis indicates that dietary changes toward fewer animal and more plant-based foods are associated with significant benefits due to reductions in diet-related mortality and GHG emissions #govegan