Individual dietary structure changes promote greenhouse gas emission reduction

Abstract

Reducing greenhouse gas (GHGs) emission in the food system, which has contributed one third of the total GHGs emissions from human activities, is crucial to achieve the Paris Agreement Announcement to limit global warming to 1.5 °C or 2 °C above pre-industrial levels. The intensity of GHGs emissions from different food varies significantly, so dietary structures will certainly lead to different global warming impacts. Adjusting people's diet structure, reducing red meat and other high carbon emission foods in the production process, and increasing low carbon healthy foods such as vegetables and seafood, can not only meet people's health needs, but also reduce GHG emissions in the food production process and promote the development of cleaner production. This study estimated GHGs emissions from human food consumption at a global scale and analyzed the driving factors. To explore the reducing path of GHGs emission from individual diets, two scenarios (a plant-rich diet and a diet with mussels replacing some of the traditional carbon intensive meat) of different diet structure were evaluated. Results suggest that the cumulative GHGs emissions caused by food consumption in 2020–2060 are 374 Gt CO2 equivalent. Furthermore, the plant-rich diet can reduce total GHGs emissions by 41%, and the mussels-replacing diet can have a reduction of 4.5%, 13.6%, and 22.4%, by replacing the traditional meat by 10%, 30% and 50%, respectively. Therefore, diet structure optimization has huge potential in GHGs emission mitigation, and such affordable and effective reduction measure can provide new insights for policy makers to control emissions from the food system.