The International Day of Zero Waste, established by United Nations General Assembly resolution 77/161, is jointly facilitated by the United Nations Environment Programme (UNEP) and the United Nations Human Settlements Programme (UN-Habitat). Celebrated on March 30th annually, the event highlights the importance of sustainable materials management and responsible consumption and production. This year’s theme is food waste.
According to UNEP, in 2022, while 783 million people went hungry globally, 1.05 billion metric tons of food were wasted (nearly 19% of all food available to consumers). Most food waste occurs in households (60%), followed by food service (28%) and retail (12 %), proving that food waste is a global challenge that requires action everywhere. According to Feeding America, 48 million people in the United States face food insecurity–including 1 in 5 children.
UNEP states that food waste alone accounts for up to 14% of global methane emissions, a powerful greenhouse gas. The US EPA estimates that up to 40% of food is wasted nationally, and greenhouse gas emissions occur throughout the food production, distribution, and disposal process. Each year, the emissions caused by wasted food in the US are greater than the emissions from all domestic flights plus all international flights run by US airlines.
EPA also estimates that the average family of four spends almost $3,000 per year on food that does not get eaten.
Thus, fighting food waste is a cost-effective and achievable climate action that also supports human health and well-being.
So what can you do to fight food waste? Check out this ISTC blog post from October 2025 for several ideas and resources to help you with smart meal planning, proper food storage and safety to avoid spoilage, and resources to help you create meals with the ingredients you already have on hand.
Learn more