Softpedia: An international collaboration of scientists argues in a new study that the world's forests have been undergoing a browning process for more than 20 years, and say that this process leads to a significant decrease in overall photosynthetic activity. Photosynthesis is one of the most important natural processes occurring anywhere on Earth. Through it, plants convert carbon dioxide from the atmosphere into oxygen, in the presence of light, water and nutrients from the ground. Without it, we would...