25 August 2010

Stop Wasting Food, Save The World's Energy

Excerpt from the
New Scientist, 18 August 2010

'...we could save an enormous amount of energy by tackling the huge problem of food waste. Doing so is likely to be quicker than many of the other options on the table, while also saving money and reducing emissions.

The energy footprint of food is enormous. Consider the US, where just 5 per cent of the global population consumes one-fifth of the world's energy. Around 15 per cent of the energy used in the US is swallowed up by food production and distribution. Most of that comes from farming with mechanised equipment, fertilisers and pesticides, irrigation and so on. Then there's the energy cost of sorting, processing and packaging.

On top of that, each item of food on an American plate has made an average trip of over 2400 kilometres by boat, plane, train or automobile. Then there's unloading, stocking grocery stores and meal preparation. By the time all of these steps are accounted for, food takes a significant bite out of the US's total annual energy budget of about 100 million terajoules.

We have to eat, of course, but what about the food that we produce but do not eat?

Between one-quarter and one-third of the food produced in the US gets wasted, for a variety of reasons. A great deal spoils or is discarded before even reaching consumers, on farms, in fisheries and during processing. Buyers often reject perfectly edible produce because of minor blemishes. Food gets tossed in the trash in the home just because we bought or served too much, or let food spoil. Over a year, the average American family of four spends almost $600 on food that they do not eat.

Between one-quarter and one-third of all the food produced in the US gets wasted Whatever the reason, food waste has a large cumulative impact. A recent analysis by one of us (Michael Webber) and Amanda Cuéllar at the University of Texas at Austin found that close to 2.2 million terajoules embedded in food waste was discarded in the US in 2007 - the energy equivalent of about 350 million barrels of oil (Environmental Science & Technology, DOI: 10.1021/es100310d).

This means that at least 2 per cent of the total US energy budget is literally thrown in the trash. For comparison, 350 million barrels of oil is nearly double Switzerland's total annual energy consumption. Only a small fraction of what is wasted is ever recovered.

Global energy consumption is projected to increase by close to 50 per cent between 2006 and 2030. That makes reducing our dependency on fossil fuels even more challenging.

Tackling food waste should be added to the toolbox of policy options because its relative impact is on the same scale as more popular measures such as biofuel production and offshore drilling...'

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