UN experts say food waste is driving up global greenhouse gas emissions

As the world marked International Day of Awareness of Food Loss and Waste on Tuesday, the United Nations said food waste is helping to fuel global warming, one half-eaten sandwich at a time.

In fact, throwing out leftovers only adds to the mountain of discarded food decomposing in landfills where it produces the powerful greenhouse gas, methane, which is far more potent at trapping heat that carbon dioxide.

“Food loss and waste generate an estimated 8 to 10 per cent of global greenhouse gas emissions,” said Michael Muratha, Project Manager and Knowledge Expert at the UN Environment Programme.

UNEP said every day, over a billion meals are left uneaten, whether due to excess food production, spoilage, or simply poor meal planning.

“Thirteen per cent of food is lost after harvest and before reaching store shelves, while another 19 per cent is wasted in homes, supermarkets, and restaurants,” said Muratha.

“When food is lost or wasted, the land, water and energy used to produce it are also wasted,” he added.

UNEP said better handling, storage, and transport can reduce post-harvest losses, while cold-chain infrastructure is important for fruit, vegetables and other perishables.

The focus of this year’s this year’s campaign, convened by UNEP and the UN Food and Agriculture Organization, was forest protection and sustainable agrifood systems.

“Using the food we already produce more efficiently can reduce pressure on land and forests and help feed more people,” said Muratha.

Moreover, having healthy forests also support food production in several ways, including by protecting soils and regulating rainfall.

Muratha highlighted some practical solutions.

“UNEP-supported projects across Africa use black soldier fly larvae to turn organic market waste into animal feed and fertiliser,” he said.

“A 2025 report estimates this could create 25,000–76,000 additional jobs in Kenya by replacing some conventional poultry feed with insect-based feed.”

The agency is further showcasing inventive ways – from simple to cutting edge - to keep food out of landfills.

“UNEP is also exploring how AI can help households identify what they waste most, plan meals around food they already have, and improve shopping and storage,” he said.

“Supermarkets can similarly use demand forecasts and timely discounts to reduce unsold food. The key is that solutions—whether simple or digital—must be affordable, practical and suited to local needs,” he added.

UNEP is also backing efforts to redirect safe surplus food to people who need it.