What is ‘local’?

When determining whether local food is greener, one problem is that there is no universally accepted definition of what ‘local’ is. We can define ‘local’ in several terms.

Geography

The word ‘locavore’ is defined by the New Oxford American Dictionary as a local resident that tries to eat only those food planted and produced within a 100-mile radius. Although the 100 mile is not a universal standard for local markets, it provides a starting point to understand local. The Campaign to Protect Rural England (CPRE) defines ‘local food‘ as the product produced within 30 miles from where it is sold. Sometimes ‘local’ means the food produced within a nation, a state or a province.

Other characteristics

The geographic definition is only one component of defining ‘local food’. There are other characteristics listed that consumers contribute to understanding the ‘local food’. Some customers may link it with the food production methods. And some others may extend it with who produce the food. These two aspects are associated with the factors that contribute to the stories behind the food. As to the perspectives of social connection, trust as well as mutual exchange, social embeddedness is regarded as one key factor of direct agricultural marketing. In addition, local food can be defined through the intermediate stage of the supply chain. A short food supply chain can facilitate the relationship between food consumer and producer because it provides clearer information about the origin of the food product.

Why buy ‘local food’? (The environmental benefits)

Local food can be good for the environment. It has been listed in the report of the Policy Commission on the Future of Farming and Food that local food markets could facilitate all perspectives of sustainable development which refer to economic, environmental and social ones. Focusing on the environmental aspect, buying local food can cut down on the pollution, noise, and traffic congestion from food miles. Roughly, the food mile concept indicates the distance food travels from farms to the plates. It also can provide access to consumers in how the local land near them is farmed and how the food is grown. In addition, it supports a more sustainable way of land planning.

The benefits of local food and examples are also highlighted in Food Strategies provided by different councils. In the Sustainable Food Strategy 2010-2015 (Haringey Council), more than 20% of the greenhouse gas (GHG) emissions around the world can be traced back to the transportation and storage of food. The Haringey Council in London highlighted that the growing local food can help to reduce these emissions and it can enhance the urban environment as well as supporting biodiversity. As to the Sheffield City Council, it developed the Sheffield Food Strategy 2014-2017. The Sheffield City Council encourages people to buy locally and get involved in growing food on their own. By doing these, the benefits can be brought such as reducing food miles and reducing food packaging which improves sustainability. Furthermore, the council also lists that there are potentials for growing food around housing and in parks or schools which support the environment through sustainable land planning. One example is that the Heeley City Farm and partners create a network of more than 20 local food growing community and school gardens in Sheffield and nearby areas.

Is it the whole story?

Localization can but it does not necessarily cut down the GHG emission and the energy use. To assess the overall impact of food systems, life-cycle analysis (LCA) is introduced to track GHG emission and energy use more comprehensively. It generally considers the direct emissions from activities. These refer to the production and transportation. LCA also takes the emissions accumulated during the manufacture of inputs into account which include fertilizer, electricity, and pesticides.  The food mile is a good idea to measure how far the food has been traveled while not a good one to assess the food’s environmental impact. To discuss the environmental impact of food, several factors should also be considered.

屏幕快照 2019-01-08 00.44.34
Components of food system LCA and the inputs 

 

The way how food is transported matters. For instance, trucks are 10 times less efficient at moving freights, ton for ton, than trains are. It would be the case that buying locally is good for the environment if you compare the exact same food supply systems and the same way of growing food. As a result, people could eat potatoes trucked in from 10 miles away, or transported by trains from 100 miles distance. The GHG emissions related to the transportation for both cases are roughly the same.

However, transportation is calculated by Weber and Matthews that only takes 11% of the overall life-cycle GHG emission. In addition, the final delivery from producer to the point of sailing only accounts for 4% of the U.S. food system GHG emissions. 83% of the emissions are calculated before the food leave the farm gates.

How the food is grown is important. Focusing on GHG emission, a researcher, Carlsson-Kanyama, found that there would be less emission for Swedes to buy tomatoes grown in Spain than in Sweden. The tomatoes were grown in fossil-fuel-heated greenhouses while the Spanish ones were in open field. So we need to consider critically the environmental costs of local production than just food miles to make more ecological sense.

Different types of food diets and products can contribute to energy use and emission throughout the food system differently. Meat and dairy products take half of the proportion of U.K. food system GHG emission. A large portion of emissions of these two kinds of food products take the forms of methane and nitrous oxide. Based on the calculation, Weber and Matthews believe that dietary shift from red meat and dairy products to vegetables, fish, egg, and chicken can be a more effective method of lowing food-related climate footprint comparing with ‘buying local’.

Buying local food can get people to think about the issues to eat in more environmentally sustainable ways. But more sophisticated approaches should be adopted to reduce food-related climate footprint.