Addressing the greenhouse gas emissions associated with food distribution: a case study of Californian farmers’ markets

American consumers’ growing taste for locally produced food has resulted in the proliferation of farmers’ markets in the U.S. While benefits abound, the very success of these markets has created an inefficient network; farmers drive long distances with small cargos multiple times each week. Not only does this increase costs, but on a per unit basis, the energy usage and resultant greenhouse gas emissions associated with supplying farmers’ markets can be greater than those associated with the equivalent supermarket distribution. In this case study, we investigate the outbound journey of food from a farm to a farmers’ market and compare it to corresponding conventional journeys, finding farmers’ market distribution indeed produces greater emissions. We then model Northern California’s farmers’ market network, solving a mixed integer transportation problem to quantify the aggregate distance travelled. We next insert a consolidation center. Farmers can transport goods either directly to the market or to this center for aggregation with other farmers’ offerings. Solving the new model shows that significant savings are possible. While admittedly rife with implementation barriers, such a solution could allow small farmers to profit from economies of scale while still retaining their independence and preserving the diversity of the markets. We view this study as a first step towards reworking the system to enable consumers and producers alike to enjoy the benefits of farmers’ markets while reducing costs and greenhouse gas emissions.