Find the fast-food restaurant that buys the most organic coffee beans.

Even fast-food java should come from sustainable sources.

RODALE NEWS, EMMAUS, PA—We drink a lot of coffee. In fact, the U.S. consumes one-fifth of the world's supply, thanks in large part to a tendency for coffee joints and fast-food restaurants to sell it on every street corner. However, the world's coffee farmers don't often reap the benefits of our caffeine habit. Commodity prices for coffee rise and fall, affecting growers' incomes and causing them to turn to cheaper growing methods that can involve deforestation, child labor, and pesticides.

Many large coffee chains have started paying closer attention to the plight of the coffee farmer, and to the crop's environmental impact, and are switching to certified-organic coffee (grown without pesticides) or fair-trade coffee (purchased from farmers who receive a higher-than-average price for coffee grown in responsible ways without the use of child or slave labor). McDonald's and Dunkin' Donuts, two of the country's largest coffee sellers, have both moved towards a greener coffee supply chain, so we wanted to crunch the numbers and see who's having a greater impact.

This: McDonald's

Pros: McDonald's is a multibillion dollar company that amassed more than $23 billion in global revenues in 2008, and coffee accounts for around 5 percent of that amount. So their choices can have big consequences. In 2005, McDonald's started selling Newman's Own certified organic and Fair Trade Certified coffee in 600 stores throughout New England and in Albany, NY. At the same time, the chain has started selling coffee certified by either the nonprofit Rainforest Alliance or other environmental groups in all 6,628 stores in Europe, which is evidence that supplying a large number of stores with greener beans is possible.

Cons: In the grand multinational scheme of things, 600 stores is a pretty tiny amount, representing a mere 4 percent of McDonald's stores in the U.S. Plus, McDonald's continues to use polystyrene foam coffee cups; they aren't recyclable and they expose coffee drinkers to the potentially cancer-causing chemical styrene.