Population Explosion

Is the worlds population really spiralling out of control???

The Demographic Transition Model

Learning Objectives:

• To know what the DTM is and what it shows

• To understand that different countries go through different stages of population change.

VS

Re-cap• Worlds population is rapidly expanding.

• Richer MEDCs = lower birth rates.

• LEDCs have higher birth rates than MEDCs.

• Death rates around the globe are relatively low. But are lower in MEDCs.

• The bigger the gap between birth rate and death rate the greater the natural increase.

Demographic Transition =The change from high birth rates and death

rates to low birth rates and death rates.

The Demographic Transition Model is a diagram which shows the relationship between BR and DR and how these affect the total population.

BR – DR = NI

What is the BR and DR going to be like here? What will be happening

to the population?

TIME

Birth

rate a

nd

de

ath ra

te p

er 10

00

of p

op

ulatio

n

Stage 1

• Stage one - the total population is low but it is balanced due to high birth rates and high death rates.

Stage 2

• Stage two - the total population is starting to rise as death rates start to fall due to improvements in health care and sanitation but birth rates remain quite high.

Stage 3 – (NIC’s)

• Stage three - the total population is still rising rapidly, but the gap between birth and death rates narrows due to fewer children needed to work in farming and the availability of contraception. Now the natural increase is high

Stage 4

• Stage four - the total population is high, but it is balanced due to a low birth rate and a low death rate. Birth control is widely available and there is a desire for smaller families.

Stage 5

• Stage five - the total population has peaked and is beginning to fall. Caused by an ageing population with very low birth rates due to many women choosing careers rather then families and expense of having a family putting many off.

TASK:

Using the statements 1 – 10 write the number where you think it goes on the DTM.

Stick the DTM in your book and cut out the list of statements to keep as a key. Stick these into your books also.

1. Billy White loses his job as a grave digger.

2. Parent start to think carefully about family planning.

3. Children are warmer in bed at night because they have more brothers and sisters.

4. There are more golden wedding anniversaries

5. A mother sobs over the grave of the last of her six children who tied from a typhoid epidemic.

6. A lot more houses are being built.

7. The public health inspector smiles as the building of the new sewers is finished.

8. Fewer children share a bedroom.

9. Grandparents are rare.

10. The cost of living is very expensive.

11. Mary is 29, she has just finished her Phd in biomedical science and is about to start her career.

Starter

Extension: Using pages 136 – 143 of Atlas, look at birth rates and death rates for:

(a) - Belgium, (b) – Botswana, (c) – Australia, (d) – UK,

(e) – Kenya, (f) – Brazil, (g) – Cambodia, (h) Congo

Place the letter on the DTM by the stage it goes with, now create a key. Highlight LEDCs and MEDCs.

True or False

• The DTM shows the relationship between BR, DR and NI.

• Stage one is stable with a high population.• During stage 2 the population in rising.• During stage 4 the birth rate is high.• During stage 3 the death rate is high.• LEDCs are in stages 1-3.• MEDCs are usually in late stage 3 – stage 4.