Mongabay: Biochar–the agricultural application of charcoal produced from burning biomass–may be one of this century’s most important social and environmental revolutions. This seemingly humble practice–a technology that goes back thousands of years–has the potential to help mitigate a number of entrenched global problems: desperate hunger, lack of soil fertility in the tropics, rainforest destruction due to slash-and-burn agriculture, and even climate change. “Biochar is a recalcitrant form …