Calculating the carbon footprint
German researchers found that large operations were more energy efficient than small, local producers.
It would be a good idea for the tree fruit industries of Washington and Oregon to calculate how they stack up in terms of their carbon footprint, says Dr. Clark Seavert, agricultural economist at Oregon State University. "They need to do it."
Seavert thinks concern about food miles and the resources used in producing and transporting food is more than just a passing fad. Even big nonfood companies such as Nike and Xerox are talking about reducing their carbon footprint.
"I think this is where we're heading," he said. "All these discussions about organic and small farms are passé. That's history. I think where we're headed is the carbon footprint. What does it take to produce a pound of fruit?"
Dr. Lynne Carpenter-Boggs, coordinator of Washington State University's Biologically Intensive Agriculture and Organic Farming program, said food miles are a valid concern because of the likelihood that transportation costs will continue to rise and also because the sustainability of our energy sources is poor from the environmental, economical, and political standpoints.
She noted that it is difficult to quantify the energy used in various production practices and to identify those that use the most. However, the energy used in growing crops is a relatively small part of the total energy used in getting foods onto consumers' plates, she said. Considerable energy is involved in transporting foods home from the grocery store, refrigerating them, and cooking them.
One thing producers could do to reduce energy use is try to produce varieties that extend the harvest season so that they can be sold fresh over a longer period of time, rather than held in cold storage, Carpenter-Boggs suggested.
A study conducted in New Zealand entitled "Food Miles—Comparative Energy/Emissions Performance of New Zealand's Agriculture Industry" concluded that less energy was involved in producing apples in New Zealand and exporting them to the United Kingdom market than in growing the fruit in the United Kingdom. The main reason was the greater efficiency of New Zealand production systems.
The study took into account all the growing practices, from pruning to spraying, mowing, fertilizing, and harvesting. It included the energy used in buildings and by vehicles, machinery, and irrigation systems on the farm, as well the energy used to ship the apples across the world.
But a study done in Germany entitled "Food (miles) for Thought," which compared New Zealand and German Braeburn apples on the market in Germany in April, drew a different conclusion. It calculated that it was more energy-efficient to produce them in Germany and keep them in controlled-atmosphere storage for five months than to import Braeburn apples from New Zealand.
The German researchers, Michael Blanke and Bernhard Burdick, were particularly interested to find out whether several months of cold storage in Germany would compensate for the energy required to ship the New Zealand apples to Europe.
Like the New Zealanders, they figured that the energy used to grow the fruit was lower in New Zealand because of higher yields. But, they calculated that shipping the apples 23,000 kilometers (more than 14,000 miles) by reefer from Nelson to Antwerp used 2.5 millijoules of energy per kilo of apples, compared with only 0.8 MJ per kilo used for 150 days of CA storage in Germany.
The authors noted that energy use does not represent all the environmental issues of fruit imports. Other considerations include carbon dioxide emissions, the value of orchards in preserving the countryside, local employment, product traceability, fruit quality assurance systems (such as Eurep-GAP), and fruit availability.
Other researchers in Germany have pointed out, however, that large-scale producers can take advantage of an economy of scale that small, local producers cannot. Elmar Schlich and Ulla Fleissner at Justus Liebig University, Giessen, compared imported apple juice and lamb meat with locally produced products, and noted a strong relationship between production costs and the number of items produced. Similarly, they say, there is an ecology of scale. Small farmers need more energy to produce and distribute their products than larger producers do. Ecological benefits come from the operating efficiency rather than the marketing distance. Claims that regional food production is preferable to global systems are not generally valid, they concluded.