February 24, 2010

Over Christmas I was listening to some children discuss what they thought was their best Christmas present ever. One boy said that he had asked his grandmother what the best present was that she had received as a child. Her reply was “When we were children, we would get oranges for Christmas.” Not surprisingly, this was a puzzling answer for Canadian 10 year olds in 2009. To them, oranges were something that they saw in a bowl on the kitchen counter almost all year long. Getting oranges for Christmas was comparable with getting socks. If you woke up on Christmas morning and got socks, you knew that you had had a bad year. I may not be as old as that boy’s grandmother, but I too can remember getting oranges for Christmas. And it wasn’t a sign that I had been naughty rather than nice. But eavesdropping on that conversation reminded me that our food system has changed dramatically during my lifetime.

For a long time, most Canadians have not thought very much about the system that delivers their food. We go to the grocery store and select from a larger and larger set of food options available at prices that, in real terms, put less and less pressure on the family budget.   But recently, food-consciousness has been increasing in Canadian consumers. People are taking a more active interest in various attributes of the food that they eat. One of the attributes that has become more important is the environmental effects of the food system. Some people, in an effort to be more careful about these environmental effects, have become part of what I will call the local food movement. One example is the 100 mile diet, according to which people attempt to eat food that was produced on farms within 100 miles of where they eat. One of the reasons that some people have advocated the consumption of local food is based on a claim of environmental benefits. I think that it is a good thing for people to think about the environmental effects linked to the food they eat. But focusing on local food is, at best, an imprecise way to promote environmental stewardship. And, in some cases, an emphasis on local food could even harm the environment.

We now have the benefit of more than 30 years of empirical research on the environmental effects of agriculture in developed countries. And we are aware that there are negative environmental effects from some aspects of our food system.   The evidence indicates that the most important negative effect of agricultural production globally is displaced sediment. Certain types of tillage systems, when employed on sloped fields exposed to heavy precipitation or when dry bare land is exposed to high winds, translates into topsoil leaving the field. When that topsoil is deposited in streams, rivers and lakes as sediment, it impairs water quality, degrades aquatic habitats and increases infrastructure costs. Next on this list of environmental harms seems to be excess nutrients, either from the application of livestock manure or synthetic fertilizer. Excess nutrients, particularly nitrogen and phosphorous can reduce water quality and contribute to human health problems and algae growth. The next most important category of harm appears to be bacteria, usually from livestock manure. Bacteria end up in ground and surface water, with effects ranging from the disappointment of beach closings to more acute cases of human illness and even death. The next item on the list, and this one is growing in importance, is odour from livestock operations, particularly as those operations increase in size and as urban to rural residential migration takes place in higher income countries. Again, the effects range from the inconvenience of the smell of manure to cases of odour-caused illness. Next on the list would be wildlife habitat as forested land is converted to agricultural land. This transformation took place in Canada a long time ago. But is taking place in some middle and low income countries now. The final item on the list, and this belies most people’s expectations, is pesticides. Although this risk category seems to garner most of the public attention on the environmental hazards of contemporary agriculture, that actual research evidence suggests that this is a less significant category of risk than the items mentioned earlier.

Of course, reasonable and informed people can disagree at the margin with my ranking. A case could be made that the wildlife habitat effects are more significant, particularly if we use, say, the beginning of the 18th century as our reference point for the transformation of forested land to agriculture in North America, or the beginning of the 17th century for western Europe. And certainly public opinion seems to rank pesticide use as a much higher risk category than does most of the research community. But, in the present context, the important thing is that none of the items on my list has anything to do with location. From an environmental stewardship point of view, how my food is produced is far more important than where it is produced. And there are significant differences, regionally, on the environmental implications of how food is produced. For example, agriculture in western Europe is far more input intensive than the agricultures of, say, New Zealand and Canada. Input intensity is measured by indicators like livestock units per unit of agricultural land area or average fertilizer use per hectare. More intensive agriculture, holding management and technology constant, is more environmentally hazardous agriculture. So, consumption of food from a lower input intensity agriculture generally involves less environmental risk than from food produced in a higher input intensity agriculture. Seasonality or production also has important environmental implications. Fruit and vegetable production seasons in the northern and southern hemispheres alternate, creating the option of year round access, with transportation, as an alternative to either local production with off season demand being met by preservation techniques, including controlled atmosphere storage, and local controlled environment production, both of which involve complex environmental tradeoffs of their own.

So, environmentally motivated food consumers, whose numbers, thankfully, are growing, need to look beyond where their food is produced and think more about how it is produced if they really want their eating habits to contribute to environmental stewardship. The good news is that farmers, food processors and retailers are starting to recognize this. Production attribute food, that is food that is differentiated on the basis of how it is produced, is increasingly visible in the market place.

Of course, other claims are made in support of local food consumption, including, “It’s good for the local economy,” and “the quality of local food is higher,” but this piece is already too long. So I will leave those topics for another day.   In the meantime, let me suggest two recent reports on the local food issue.

Pierre Desrochers and Hiroko Shimizu (2008) Yes, We Have No Bananas: A Critique of the “Food Miles” Perspective, Policy Primer No. 8, Mercatus Policy Series, Global Prosperity Initiative, Mercatus Center, George Mason University, October.

Department for Environment, Food and Rural Affairs (2009) First Report from the Council of Food Policy Advisors, Government of the United Kingdom, September.