Saturday, 4 September 2010

U.S. food industry using more energy

To reduce greenhouse gas emissions in response to climate change, it is essential to reduce energy use in the U.S. food system. A USDA report this Spring described trends in exactly the wrong direction.

USDA economist Patrick Canning and colleagues estimated that energy use in U.S. agricultural and food industries increased by 23% -- from 11.5 to 14.1 quadrillion British thermal units --  from 1997 to 2002, the most recent data available [typo corrected Sep. 7].  The increase is so large that it accounted for 80 percent of all increased energy use in the United States.

Only one quarter of the increased energy use in the food system is due to population growth.  Another quarter of the increase is due to increased food spending per person.  Fully half of the increase was due to adopting more energy intensive technologies in the food system.

At a time when one might expect that Americans would adopt more energy efficient technologies, we did the opposite.  We continued to move from labor intensive to energy intensive methods throughout food production and manufacture.  A fascinating accompanying article (.pdf) in the USDA magazine Amber Waves gives the example of adopting high-technology energy-intensive hen houses in the egg industry, increasing energy use per egg by 40%.

Consumers, similarly, were splurging on energy rather than economizing.  We purchased more dishwashers, microwave ovens, self-cleaning ovens, and second refrigerators than ever before, so our own household food systems were also becoming more energy intensive.

In some circles, there is a temptation to hope that technological improvement will solve our energy and climate change problems, making it unnecessary to change consumption habits.  This research casts some doubt on this hope.  Consumption change remains important.

A popular way to reduce the energy impact of our food choices is to buy local.  The energy used in transportation varies greatly by food group.  For example, shipping rice long-distance by ship or grain by train is fairly innocuous, while shipping fresh produce from across the country and overseas may be a more spendthrift use of energy.  Packaged food and restaurant food are both more energy intensive than home-prepared food from real ingredients.  The USDA article emphasizes food from animals as another important consumer choice:
Based on 2002 energy technologies, if households choose to substitute a portion of their at-home meat and egg consumption with expanded fish and fresh vegetable consumption, for example, there could be substantial savings in energy usage.
Reread this sentence.  This is a bold conclusion for a USDA magazine article.

Click for larger image.

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