Environmentalists consider buying local to be one of the most important steps in going (and being) green. Frequenting farmers markets is one of the most common and easiest ways to buy local; most of the vendors come from farms nearby where their products were grown, created, produced, etc. If unable to visit a farmers market, regular grocery stores often offer source information for their foods and products sold.
Buying items produced locally not only supports the local economy (which is a good thing, too), but it also reduces carbon emissions in the transportation process. An apple grown 10 states over, or a pair of jeans produced in another country, has to travel quite a distance to get to you, whereas the same item produced in your state or region has a much smaller distance to travel, making the emissions (and thus, the contribution to climate change) far smaller.
Consumers who choose to buy food that’s produced locally rather than in distant markets requiring significant resources to transport are called ‘locavores’.