Many environmental problems are caused by human actions including pollution, deforestation, desertification, and habitat loss. Pollution is the accumulation of harmful substances in the air, water, and ground. Deforestation is the disappearance of forests from cutting down trees. Desertification is the transformation of landscapes into desert areas as the soil becomes dry and poor. Habitat loss occurs when natural areas are destroyed for housing and industry. Children can help address these issues by reducing garbage production, avoiding cutting down trees, and protecting natural areas.