Every year 25 billion tons of topsoil of farmland is lost through erosion around the world. The root causes are the mismanagement of Earth's forests and woodlands. Forests are vanishing at the rate of 16.8 million hectares per year. Forests prevent soil erosion and provide principal means of water management. It also contributes to global warming.
Forests are also important bio-reserves.
Out of 30 million species on Earth, only about 1.5 million are recorded. The single important reason is deforestation. Environmental hazards are generated by industries everywhere. 2,100 million tonnes of solid waste and 340 million tonnes of hazardous waste are coming out of these industries. There has been a worldwide concern about the disposal of radioactive wastes from nuclear reactors.