Food waste represents an economic and social loss with far-reaching environmental consequences. It is considered a global problem, requiring greater than necessary food production and causing a substantial financial cost of about US$ 2.6 trillion per year, including US$ 700 billion of environmental costs and US$ 900 billion of social costs.
The main contributors to the carbon footprint of food waste are cereals (34% of the total), meat (21%) and vegetables (21%).
The decomposition of food waste, together with the production of cattle, sheep, goats and rice, is a relevant source of methane emissions. According to the UNEP Food Waste Index (2024), 1.05 billion tonnes of food went to waste in 2022 — approximately 19% of food available to consumers, with an additional 13% lost in the supply chain after harvest. Combined, roughly one-third of all food produced is lost or wasted globally. Middle and upper-income regions account for about two-thirds of the total carbon footprint, while their contribution to total food waste is around 50%. Furthermore, the impact of meat is even higher in these regions, because, in addition to the considerable waste of this product, more meat needs to be produced to meet the high demand.
The annual carbon footprint of food waste is about 500 kg CO2 eq. per capita. Europe, North America, Oceania and Industrialized Asia stand out as the regions with the highest emission per capita (approximately 700 to 900 kg CO2 eq. per person and per year). Sub-Saharan Africa is the region with the lowest footprint per capita (about 180 kg CO2 eq.).
In addition, the formats and sizes of packaging predetermined by the market restrict the offer only to products considered suitable or desirable by retailers. These practices cause “imperfect” edible foods to be rejected by retailers, generating waste. In this way, food hierarchies are created based only on aesthetics and not on nutrition and taste.
The prevention of food waste at the domestic level has the greatest effect to mitigate global warming since the impacts at the consumer stage include all the impacts accumulated in the previous stages of the supply chain. The food that we throw into the household garbage turns to methane, a potent greenhouse gas, whilst it is breaking down in landfill. Potentially affecting climate change. Actually, it accounts for 8–10% of all global greenhouse gas emissions (UNEP Food Waste Index, 2024).
