Stop wasting food, save the world’s energy

IT IS no secret that meeting the world’s growing energy demands will be difficult. So far, most of the focus has been on finding oil in areas that are ever more difficult to access – think BP’s Deepwater Horizon well – bringing new fossil fuels such as tar sands online and increasing energy efficiency.

Yet we have been overlooking an easier way. 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.

Whatever the reason, food waste has a large cumulative impact. A recent analysis by one of us (Michael Webber) and Amanda Cu̩llar 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 Рthe 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. Although we will never eliminate food waste completely, we can assuredly create the means to discard less by coming up with the right incentives for producers and consumers.

The first step involves identifying efficiency savings along the production chain, which might include improved farming practices or more funding for agricultural research. We already have the means to create varieties of vegetables and fruit that spoil more slowly than before, but the approach involves genetic engineering and there is consumer resistance, so public acceptance of new technologies should be encouraged.

Companies can do their bit, too. Hotels are already saving significantly on water and energy by encouraging their guests to use towels more than once. In the same manner, restaurants might reduce food waste by reducing their often profligate portion sizes.

Supermarkets could benefit by selling perfectly edible fruits and vegetables that are currently discarded because of blemishes. Such measures would not only reduce food waste but also save companies money and demonstrate that they are environmentally conscious, which in turn would enhance their reputation and increase their profits.

However, businesses function based on the demands of their customers, so ultimately we need to change people’s actions. This will be tricky.

Foremost, the public needs to be better educated about proper storage of foods to keep them edible for longer. Shoppers could be supplied with easy-to-digest, accurate information about the proper shelf life of products, so that they are able to plan meals more carefully and end up with less spoilt food at the end of the week.

Another problem is “use by” dates, which are extremely conservative and can encourage consumers to throw away perfectly edible food. Similarly, “sell by” dates are usually meant as guidelines for retailers to ensure they do not keep stock too long, not as guidance to consumers about when the food will spoil. We need to improve the way we label foods.

Initiatives targeted at consumers could also have ripple-out effects: not only will educating people about food waste reduce pressure on their wallets, it would also lead to fewer trips to the store, saving on gasoline and reducing carbon emissions. Most important, it would help to promote a culture that places a higher value on food, energy, and the way their complex relationship affects us all.

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