http://www.worldometers.info/world-population/

What will it be by the end of the lesson?

Human populations• interpret growth curves, survival curves and age pyramids• calculate population growth rates from data on birth rate and death rate.• relate changes in the size and structure of human populations to different stages in demographic transition.

Complete human population worksheet and graph

Population graphGrowth curves

The growth of the human population

• The human population growth rate should slow, but when is of debate.

Human’s are subject to the same biotic and abiotic factors

• But also when the population develops agriculture and becomes industrialised. These affect the birth rate, death rate and life expectancy• These changes are called demographic transition

There are four stages of demographic transition.Which stage are we in?

Pre –industrial mechanisation mature post-industrial age of agriculture indus age

+ urbanisation age

What factors affect the birth rate?

• Economic conditions• Cultural/religious• Social pressure and conditions• Birth control• Political factorsBirth rate = number of births per year x 100

total population in the same year

What factors affect the death rate?

• Age profile• Life expectancy• Food supply• Availability of safe water and sanitation• Medical care• Natural disasters• war

Most developed countries are in the final stage of demographic transition; developing countries are in one of the two middle stages. Therefore most population growth occurs in developing countries.

Population structure

Stable, increasing or decreasing?

Stable, increasing or decreasing?

Stable, increasing or decreasing?

Glossary

• Population growth is the actual increase of a population.

• Growth rate is the increase or decrease in numbers expressed as a percentage of the original population.

What would the growth rate be if a population of 10 million grew by 100000 in 1 year?

(100000/10000000) x 100 = 1%

Questions

1. Which two events have contributed most to the human population explosion?

2. Total population 2007 = 1 000 000Birth rate 2007 = 25 per 1000Death rate 2007 = 20 per 1000

a. How many births were there during the year?b. How many deaths were there during the year?c. Calculate the percentage population growth for

2007.