MODELS OF POPULATION AND THE ENVIRONMENT

1. MODELS OF POPULATION AND THE ENVIRONMENT By Dr. J. Kivelia Department of Geography University of Dar es Salaam

2. The Models • Several models: • PoET • IPAT

3. The IPAT Model • Demonstrates that environmental impact (I) is a joint function of population (P), affluence (A), and technology (T). • Sees population (P) as integrating with affluence (A) and technology (T) in a multiplicative manner to create impact (I) on the environment. • These factors compound each other's impacts.

4. The IPAT MODEL (cont’d) The Model is summarised thus: I = PAT Where : I = Impact on the environment P = Population (size, growth rate, distribution) A = Affluence (measured as GNP per capita) T=Technology (pollution per unit of GNP)

5. IPAT Model • I = P x A x T Environmental Population Level of Type of Impact Size Affluence Technology (# of people) (consumption (production per capita) technology)

6. IPAT Model (Cont.) • Technology in use determines: • extent to which human activities damage/sustain the environment • amount of waste associated with level of consumption. • level of pollution • type and quantity of raw materials used • Technology: • leads to new ways of finding and using natural resources, • changes efficiency of production and consumption processes. • Technology and consumption patterns determine the impact on environment per person. • Population is the multiplier that fixes the total impact

7. Food for Thought • Describe the IPAT model and the ways in which it can be used to determine the impact of population on the environment • Why is there a concern about the contemporary population growth? • Justify the philosophical dispute between Pessimists and Optimists on population growth and environmental resources