Four ways in which man has interfered with his natural environment are:
(i) Human intervention is caused by the increasing pressures with the rise in human populations, activities and demand for basic necessities of life such as housing. Such activities have caused modifications of the climate, landforms, soil, vegetation and drainage network in many parts of the world
(ii) Those human activities that are related to agriculture, grazing, mining, forest exploitation, water resources management, etc, have some damaging effect on the environment
(iii) Some of the well-known environmental hazards such as soil and coastal erosion, flooding, deforestation, land subsistence, atmospheric and water pollution are known to affect the environment.
(iv) Some aspects of human intervention have also helped to sustain the natural environment, e.g afforestation, land reclamation, artificial fertilization and irrigation schemes.