From the UK Guardian today”

“As consumers throw millions of tonnes of uneaten food into the bin each year, few give a thought to the hidden cost of such waste – the water that it took to grow the food.

But new research shows that we throw away, on average, twice as much water per year in the form of uneaten food as we use for washing and drinking.

What is worse, increasing amounts of our food comes from countries where water is scarce, meaning the food we discard has a huge hidden impact on the depletion of valuable water resources across the world.

According to the first comprehensive study into the impact of the “embedded water” in the UK’s food waste on world water supplies, more than a 5% of the water used by the UK is thrown away in the form of uneaten food.” (source)

Food production accounts for between 17 and 32 percent of all greenhouse gas emissions. About half of all food produced ends up being wasted at some point along the food chains.

While there has been a lot of focus in the press about household waste, and increasingly on supermarket waste, there is a need consider the whole food chain. Depending on the crop type and production system, 15-35% of all food grown goes to waste in before harvest, and another 10-15% during processing, transport and storage (source). In part, this in production loss is the result of the kinds of contracts that farmers have with purchasers, which require over-production to ensure they meet their contractual obligations, and the jettisoning of foods that don’t meet (what are often aesthetic) standards. Shopper psychology drives the over-stocking of supermarket shelves and all manner of factors shape household wastage.

 All of which leaves us with a massive waste problem, which is a massive resource loss. In the USA it is estimated that 98% of household food waste ends up in landfill, where there is little or no chance of resource recovery. By contrast, 62% of garden waste is composted (source).

In South Africa we lack adequate systems to reclaim precious resources from domestic and commercial food waste. Linus Opara at Stellenbosch University is leading a team working on postharvest loss technologies. Far more needs to be done here to understand the technologies, economics, biologies, psychologies and geographies that drive food waste and our failure to reclaim resources from waste