Joao Tavares..., along with his brother and father,...grow cocoa [in Brazil] using a method called cabruca — cutting down just a few of the tall rainforest trees, and planting the mid-height cacao trees underneath... The World Agroforestry Center and the chocolate manufacturer Mars Inc. are currently studying how carbon storage can be measured on cabruca-like farms, and whether a carbon credit system would help farmers — and the environment.