We must weigh the environmental benefits from shipping less food against the environmental costs of producing and storing local food in a state that doesn’t exactly have ideal conditions for every kind of produce. One recent UK report found that the greenhouse gas emissions involved in eating English tomatoes were about three times as high as eating Spanish tomatoes. The extra energy and fertilizer involved in producing tomatoes in chilly England overwhelmed the benefits of less shipping. Even New Zealand lamb produced less greenhouse gases than English lamb. Berkeley graduate student Steven Sexton estimates that an American switch to more local corn production would require 35 percent more fertilizer and 22.8 percent more energy.