Energy in wasted food

2010-08-10

in Geek stuff, Politics, Science, The environment

Here’s a sobering fact: there is apparently more energy in wasted food in the US than in the Gulf of Mexico:

Americans aren’t, technically, eating an average of 3774 calories per day. This figure is calculated by looking at food produced, divided by the number of Americans. It assumes we’re eating all that, but, in reality, according to environmental scientist Gidon Eshel we really only eat about 2800 calories per day. That whopping 3774 includes both what we eat—and what we waste…

We use a lot of energy producing, transporting, processing, storing and cooking food we don’t eat. About 2150 trillion kilojoules worth a year, according to a recent study. That’s more kilojoules than the United States could produce in biofuels. And it’s more than we already produce in all the oil and gas extracted annually from the Gulf of Mexico.

This is suggestive for several reasons. Firstly, it reinforces the point that the United States cannot drill the way out of their oil addiction problems – domestic oil supplies just aren’t adequate to make much of a difference. Secondly, it is a reminder of how energy is both a critical and a largely hidden part of our society. Thirdly, it shows how people respond to economic incentives – such as the cheapness of food – by acting frugally or wastefully in response. Fourthly, it shows yet another area where conservation can help us, as we make the shift to sustainable and zero-carbon forms of energy production and use.

{ 4 comments… read them below or add one }

Byron Smith August 11, 2010 at 9:17 am

Does the 3774 figure include food grown for biofuels?

Milan August 11, 2010 at 9:44 am

This spreadsheet from the US Department of Agriculture is interesting, though it doesn’t answer your question.

What I find surprising about it is that the large figure of kilo-calories per person per day persists well back in time. In 1909, the US was producing 3,500 kilo-calories per person per day, compared with 3,200 in 1950 and 3,900 in 2004.

I wonder how much was being wasted in 1909. Quite possibly a lot, due to less availability of refrigeration and slower transport time from farm to mouth.

Matt March 11, 2013 at 8:37 pm

Does this article make its comparison based on a food calories vs thermal calories converstion error? If so, it’s off by a factor of 1000.

. March 11, 2013 at 10:23 pm

This work estimates the energy embedded in wasted food annually in the United States. We calculated the energy intensity of food production from agriculture, transportation, processing, food sales, storage, and preparation for 2007 as 8080 ± 760 trillion BTU. In 1995 approximately 27% of edible food was wasted. Synthesizing these food loss figures with our estimate of energy consumption for different food categories and food production steps, while normalizing for different production volumes, shows that 2030 ± 160 trillion BTU of energy were embedded in wasted food in 2007. The energy embedded in wasted food represents approximately 2% of annual energy consumption in the United States, which is substantial when compared to other energy conservation and production proposals. To improve this analysis, nationwide estimates of food waste and an updated estimate for the energy required to produce food for U.S. consumption would be valuable.

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