The International Energy Agency (IEA) estimates that renewable energy sources account for about 13% of the world’s total primary energy supply. Nearly 80% of these renewables are in the form of combustible biomass—mostly wood, charcoal, crop residues, or other wastes burned for cooking, heating, and other activities in the developing world. Now, high oil prices and...
Tag Archives: sustainable agriculture
A common question but very difficult to answer. Depending on your definition of variety, the answer could be anything from zero to around 500,000 varieties of Oryza sativa (Asian cultivated rice). In the technical sense used by taxonomists (biologists who classify organisms into groups based on evolutionary relationships), descriptions have been published of 14 varieties,...