Three courses of human understanding of environmental problems

In the primitive hunting stage of "Three Courses" (1), the environmental problems faced by human beings were mainly blind and indiscriminate mining, which led to forest destruction, lack of prey and famine.

(2) In the stage of agriculture and animal husbandry, it is mainly manifested in blind reclamation and destruction of forests and grasslands, resulting in environmental problems such as soil erosion, land desertification and salinization.

(3) At present, the industrial stage is mainly characterized by over-exploitation of resources and discharge of "three wastes", resulting in ecological damage and environmental pollution.