Many die as they catch modern diseases. They contain plants and animals that live nowhere else on earth. When a rain forest is destroyed, the plants and animals which have lived there for millions of years are also destroyed. In some countries, especially those of South America, rich landowners own most of the farmland. Poor farmers have to use tropical forestland to grow food for their children.
Some farmers use forestland to grow cash crops, such as coffee or pineapples.
Other activities that are destroying rain forests include mining, logging, farming and cattle ranching. They help control the world's climate. Burning and clearing rain forests releases carbon , and this causes the weather to become much hotter. Rain forests also reduce floods and help to prevent droughts , soil erosion, and air pollution . Rain forests are the world's most important source of new medicines.