PD - The IPAT Model (Lesson)

The IPAT Model

As a way to look at the human impact on the environment, Paul Ehrlich and John Holdren (1974) developed this model. The IPAT model examines how Technology, Affluence, and Population all work together to impact the environment. It's shown as

I = P x A x T

I stands for the impact on the environment

P stands for population. The population can affect the environment because more people mean more land and resources are used and more waste is produced.

A stands for affluence. Greater affluence means larger resource consumption per person due to increased wealth.

T stands for technology. Technology can act positively or negatively either by creating ways to exploit resources faster and more easily or by developing better ways to reduce our impacts, such as better pollution controls or renewable energy.

Sensitivity can also be added to the IPAT model, taking into account the sensitivity of an environment when being used by humans. For example, deserts and grassland are more susceptible to degradation if they are not managed properly.

Cultural Carrying Capacity

Learn more about carrying capacity by clicking on the links below.

Human Population Growth Links to an external site.

What Limits the Size of a Population? Links to an external site.

World Population Links to an external site.

The Rule of 70

The Rule of 70 is a general rule of thumb that explains the time period required for a population in a constant rate of exponential growth, to double. For example, if a region of people is growing at a rate of 1% per year, then after 70 years, the population number will have doubled. If the rate for that group of people doubles to 2%, then the rate will be cut in half to 35 years.

Population Growth Rate

Overall, a population's net change in size, per 1,000 individuals, is measured by its growth rate, which is calculated as follows:

Growth Rate = (Birth Rate + Immigration) - (Death Rate + Emigration)

 

RESOURCES IN THIS MODULE ARE OPEN EDUCATIONAL RESOURCES (OER) OR CREATED BY GAVS UNLESS OTHERWISE NOTED. SOME IMAGES USED UNDER SUBSCRIPTION.