If food wastage were a country, it would be the third largest emitting country in the world. Back in 2011, the Food and Agriculture organization did a global assessment for food losses and found that one-third of all food produced in the world for human consumption never even reached the consumer’s table. This not only means a missed opportunity for the economy and food security, but also a waste of all the natural resources used for growing, processing, packaging, transporting and marketing food. Other effects include an unnecessary loss of soil fertility, expenditures of fresh water and oil, deforestation, undocumented human labor, contribution to landfills, economic losses (2012 market value of food products wasted was 936 billion dollars!), degradation of ecosystems, generation of GHG emissions. And this problem is only getting worse. In the US, there has been a 50% rise in food waste.
Waste is produced at each stage of the food supply chain. While each country produces different proportions of waste at each stage, food waste is higher in the processing, distribution, and consumption stages in high-income regions. In low-income countries, food losses occur highest in the production and post- harvesting phases.
Looking at the chart above, it is clear that the great source of food consumption comes from the last phase of consumption which means most greenhouse gas emissions of the food supply chain are coming from uneaten food, food that has already been produced but is still discarded.
Because the consumption phase has the greatest carbon footprint, bioconversion and valorization technologies are the biggest areas that scientists are looking into to most effectively manage in food waste. Looking at the figure above, the biggest contributors in the consumption phase have traditionally been managed by strategies of incineration, land filling, and composting. However, traditional strategies heavily contribute to environmental pollution. Incineration, while quick and easy, releases smoke from the chimneys which contain nitrogen oxide, particulates, heavy metals, acid gases and the carcinogen dioxin. Incineration also discourages recycling and waste reduction, and burning waste is just not a long-term solution, similar to landfills. Composting is manageable at an individual level, but not very sustainable long-term solution on an industrial commercial level. Like landfills, commercial composting requires much land as well as the right type of land and soil to set up commercial composting sites. It also may not be a practical option for land poor regions. But recently, there have been many efforts to develop new strategies of bioconversion and valorization to more efficiently manage food waste so that it is sustainable.
