Like all products, specialization and trade are essential in order for anyone to gain from sale. With food however, this is especially important. The reason is that agriculture relies on conditions and natural endowments more than any other business. The temperature, soil composition, rainfall, sunlight, terrain, and costs of land in certain areas all impact the quality and price of food. Luckily, since global trade is higher than ever, we can grow or raise certain types of food in the best places to grow or raise those foods. For example it would make no sense to grow potatoes in California, wheat in Peru, cattle in Canada, and coffee beans in France. Even though we all consume all of these things, we can't make all of them in the same place. Consumers have to decide which food to eat based on quality and price, not on where it is made. Some say that the transportation of food across the country or across the globe is costly and is a waste of money and gas. This would be true except that farmers and distributors make decisions based on what will make the most profit. So if olives are coming from Peru, there is a reason why suppliers chose to grow them there even though they have to pay for shipping. If you buy the best and cheapest olives and you live in a region that makes olives, you will be inadvertently buying locally produced food (because the cost of fuel is lower and the quality of that region's olives is higher). In terms of environmental impacts, organic non-GMO locally produced food is bad for you and the environment. This is because organic food has no resistance to pests and disease and mold and neither do non-GMO food, thus, for every ton of energy and resources put into the production of the food, very little is actually eaten by humans. If you buy potatoes grown in Alabama, for instance, because you live in Alabama and want to buy local, the potatoes were grown in conditions not suited for potatoes and so very little output for all the input is made. Buy the best, buy the cheapest, don't necessarily buy the closest!
All of human history has been about escaping hunger and scarcity of resources. Now that food is suddenly more plentiful, it's time to turn to more expensive methods again?
True that it saves local employment, you're actually spending more money than you will as it is against theory of comparative advantage.
It makes sense