Buy produce from local farmers rather than at the grocery store. Not only will your foods be fresher, they won't have made a gas-guzzling cross-country journey just to get to you.(Source: Kiplinger - Going Green on the Cheap)
Environmentalists are idealists.
They tell us to buy produce from local farmers rather than from grocery stores. The idea is that grocery stalls may get its produce from distant farms, thus contributing to higher level of carbon dioxide emission.
Consider this hypothetical example: The nearest grocery store from your home is 1 km away. The nearest farm is 20 km away. Are you going to drive all the way to the farm to make your purchase?
Next, assume that the grocery store purchases 100 kg of vegetables from a distant farm that is 50 km away. You drive to the nearest farm – 20 km from your home – to buy 2 kg of veggies. Are you sure you have helped to reduced CO2 emission?
Further assume that you are a very busy person. You work from 9am to 7pm everyday, and are stuck in traffic jam for up to 2 hours. On weekend you attend part time MBA class. Where do you prefer to do your shopping?
Assume again that your sibling owns a grocery store. Do you support the call by the environmentalists to buy directly from farmers?
While we may buy produce fresh from farm, we may store them in refrigerator for up to a week. In the end we are still not eating them fresh. Remember that we drive 20km to get to the nearest farm. We are not going to buy just enough for the day.
Green campaigns have to be practical. They must balance the interests of multiple groups involved, including, in my example above, the grocery stores. Otherwise such campaigns will not win widespread support and doomed to fail.