Food miles are an important part of the environmental footprint of food production and consumption. If you are trying to reduce your overall carbon footprint, you need to think about the sustainability of the food you are consuming. The impact of transport is important. There may be a greater footprint from a resident of North America buying sustainably farmed apples from New Zealand than non-sustainably farmed produce from California or Mexico. Another reason food miles are important is that they are part of the concept of the sustainable community, in which as much as possible one tries to buy locally produced good to reduce the culture of mass product and globalization.
Food miles are important because they provide a metric that can help guide you when making decisions in a very confusing area, or several related areas that are hard to think about.
Food miles measure how far food travels from the place of creation to where it is sold to consumers. It is one way, but not the only way, of judging the environmental impact a specific food purchase has. In many cases, the farther food travels to reach consumers, the more fuel is spent transporting it. That means you can have a way of judging how your daily purchases affect and contribute to global warming.
They also measure something else: vulnerability. Food that comes from far away is part of an extended supply chain. The longer a supply chain, the more vulnerable it is to being disrupted. If all of your food comes from far away, and war, weather, or politics disrupts shipping, your entire region may go hungry.