As experts gather in Geneva to finalise the most detailed scientific assessment yet of how we use the land we live off, one phenomenon to which we all contribute will be under close scrutiny: food waste.
Ahead of the release of the Intergovernmental Panel on Climate Change (IPCC) report on land use, here are some facts about food waste:
One third of all food
An IPCC draft summary says between 25-30 per cent of food produced for human consumption every year -- approximately 1.3 billion tonnes -- gets lost or wasted. That's a 40 per cent increase since 1970, or an additional 200 calories per person per day.
According to the UN's Food and Agriculture Organization (FAO), food loss and waste costs the global economy close to US$1 trillion each year.
It also generates as much as eight per cent of all manmade greenhouse gas emissions, the FAO says.
Inequality
But not all food waste is equal. The IPCC report is expected to highlight vast disparities between food production and rejection in rich and developing nations.
The FAO says that consumers in rich nations bin almost as much food annually (222 million tonnes) as the entire net food production of sub-Saharan Africa (230 million tonnes).
A draft of the IPCC report says that people in Europe and North America each throw away an average of 95-115 kilogrammes (209-254 pounds) of food each year; people in sub-Saharan Africa and Asia throw away just 6-11 kg.
Food 'loss' vs 'waste'
As well as wildly varying levels, the causes of food waste and loss change according to development.
Whereas in developing countries 40 per cent of losses occur post-harvest, in industrialised nations 40 per cent of losses happen at retail and consumer levels.
"In the global south it's a lot to do with a lack of preservation, lack of transport systems, food being produced in the villages and not being able to make it to market," said Teresa Anderson, climate policy coordinator at ActionAid.
"Whereas in the north much more is wasted after it gets to the supermarkets. Supermarkets themselves throw vegetables away because they are not pretty enough, or because of their size or shape."
Obesity = waste?
Around two billion people across the world are overnourished or obese, while 820 million people go to bed hungry each night.
The IPCC draft section on food waste says "consumption above nutritional needs can be seen as a form of food waste", which is "at least as large a contributor to food system losses" as throwing food away.
