The pollution from food is sneaky. Because the apple sitting on your kitchen counter isn't really causing any harm. But chances are good that you didn't pick it from a tree in your backyard. It required land and water to grow, machines to harvest and process, packaging to ship, trucks to transport, and often refrigerators to store. Much of that process releases planet-warming greenhouse gases into the atmosphere.

That's why the global food system makes up roughly a third of worldwide human-caused greenhouse gas emissions, according to the EDGAR FOOD pollution database.

Meanwhile, roughly a third of the U.S. food supply is lost or wasted without being eaten, according to the U.S. Department of Agriculture. It might never get harvested, it might spoil in transit, or the grocery store might reject it for being the wrong size or color. That's a big reason why some consumers are looking for less-wasteful alternatives, ranging from farmers markets to delivery services for produce that didn't meet supermarket size or appearance standards.

There's a whole breadth of opportunities to purchase food, said Julia Van Soelen Kim, food systems adviser with the University of California Cooperative Extension.

Jane Kolodinsky, professor emerita at the University of Vermont and director of research at Arrowleaf Consulting, has bought her produce directly from a local farmer for 30 years. It's called Community-Supported Agriculture, or CSA. At the beginning of every harvest season, Kolodinsky pays that farm a fee. Then, once per week, she picks up a box of produce at the farm. Some CSA programs pick the produce, while others let you customize. Some deliver. An online database shows which farms participate in CSA programs.

Since the food is grown nearby, there is less processing and packaging. There's a smaller carbon footprint for purchasing locally compared to global or national food distribution channels, said Van Soelen Kim. When they're local, they're traveling less distance, so less gas, less fuel.

Kolodinsky said the oldest alternative food system is the farmers market, where vendors gather and sell directly to consumers. Growers also sell at farm stands that aren't tied to a centralized, scheduled event. Farmers markets allow consumers more flexibility to pick the produce than a typical CSA.

This article was provided by The Associated Press.