Forests create air, store water, and make soils. However, loss of such forests cause it impossible to store water and create soils. As a result, important soils flows into mountains. The lack of soil reduces harvests, and the flow of soils into seas makes it impossible for fish to live in that water area. Deforestation means not only dynamically change the ecosystem of forest but also the system of ocean.
Deforestation is a cause of the food shortage.
Therefore, the global population keeps increasing, and the demand for foods is also increasing. However, many factors prevent us from gaining crops. In many countries, the food shortage is predicted. At present, we are enjoying affluent life. However, the global food crisis will break around 2010.