An experiment going on in a corner of eastern Brazil has attracted worldwide attention. Right in the midst of a thinning rainforest cacao trees are planted.

There's a lot less rainforest than there once was. There used to be 330 million acres of rainforest in eastern Brazil, called the Mata Atlantica. Settlers arrived hundreds of years ago and began destroying the forest for the wood, and to create fields for pasture and crops. Only 7 percent of the Mata Atlantica remains, and destruction is still going on. Every time a tree is burned, its stored carbon is released. As more carbon is released into the air, the planet gets warmer.

That worries Dario Ahnert, a plant expert at the State University of Santa Cruz in Eastern Brazil. He says farmers need an incentive to save the remaining forest, and he hopes chocolate will be that incentive. Chocolate used to be a huge industry here, but in the past two decades, plant disease and low prices in the world market for cocoa beans devastated the industry. Farmers turned to other ways of making a living, including logging trees or burning the forest for farmland or pasture. When the nutrients in the soil were used up, the land was abandoned.

Ahnert wants to persuade farmers to return to chocolate farming and preserve the forest. His friend, Joao Tavares, shows it can be done, reports NPR, an independent radio network in the US.