The food the world wastes accounts for more greenhouse gas emissions than any country except for China and the US, the UN said in a report last week.

Each year, about a third of food for human consumption, around 1.3 billion tonnes, is wasted, along with the energy, water and chemicals needed to produce it and dispose of it.

Almost 30 per cent of the world’s farmland, and a volume of water equivalent to the annual discharge of the River Volga, are in effect being used in vain.

In its report entitled The Food Wastage Footprint, the UN Food and Agriculture Organisation estimated that the carbon footprint of wasted food was equivalent to 3.3 billion tonnes of carbon dioxide per year.

If it were a country, it would be the world’s third biggest emitter after China and the US, suggesting that more efficient food use could contribute substantially to global efforts to cut greenhouse gases to limit global warming.

In the industrialised world, much of the waste comes from consumers buying too much and throwing away what they do not eat. In developing countries, it is mainly the result of inefficient farming and a lack of proper storage facilities.