By Nazil Abbas
Rotting food waste accounts for up to 10 per cent of global greenhouse gas emissions — about five times more than the entire aviation sector — the United Nations Environment Programme (UNEP) has warned.
The agency said food waste remains a largely overlooked driver of the climate crisis, despite the existence of practical solutions to curb its impact.
Food waste covers everything from unfinished meals and spoiled produce to crops lost between harvest and retail. UNEP said the most harmful is food that ends up decomposing in landfills, where organic matter buried without oxygen interacts with microorganisms to produce methane.
Methane is a highly potent greenhouse gas responsible for nearly one-third of current global warming. It traps 86 times more heat than carbon dioxide over a 20-year period.
According to the UN, decomposing food is therefore a major source of global methane emissions. In the United States, municipal solid waste landfills rank as the third-largest source of human-related methane emissions.
Beyond climate, food waste is also driving unnecessary loss of natural resources.
More than one billion meals go uneaten daily, according to UNEP’s Food Waste Index Report, with households responsible for about 60 per cent.
The Food and Agriculture Organization (FAO) estimates that 1.4 billion hectares of land — about 28 per cent of the world’s agricultural area — is used to grow food that is never consumed. The waste also fuels deforestation, as forests are cleared for agriculture to produce food that is eventually discarded.
UNEP said cutting food waste offers one of the fastest and most cost-effective ways to slow global warming because methane stays in the atmosphere for a much shorter period than carbon dioxide.
Martin Krause, a UNEP official, said tackling food waste could deliver rapid climate benefits at a time when countries are searching for practical measures to curb warming.
Despite global pledges, however, FAO has warned that there has been no tangible progress in reducing food losses since 2015, leaving the world far from meeting the Sustainable Development Goal target of halving per-capita food waste by 2030.
Governments are now exploring more sustainable waste management approaches.
Eleven African governments have committed to cutting methane emissions by integrating waste pickers into formal systems, including training them to separate and compost organic waste. With support from the Climate and Clean Air Coalition convened by UNEP, the initiative has led to the establishment of community composting sites.
In parts of Africa, black soldier flies are also being deployed to recycle organic waste, with specialised facilities breeding the insects for waste processing in countries including Malawi and Uganda.
UNEP said such approaches show that organic waste can be managed in ways that reduce emissions while delivering environmental and economic gains.
