Why has the world population changed over time?

Learning Objective:

To analyse the pattern of population growth over time.

21 April 2023

Numbered Heads

Together

1. Write your own answers to the questions.

2. Then put your “heads together” to compare answers and make sure everyone has an answer to each question.

3. Then number yourselves 1 to 4.

4. When I call your number, be prepared – I may ask for your answer!

1. How has the worlds population changed over the last 300 years?

2. Why has the worlds population grown?

3. What are the implications of this growth?

Exponential Growth – Where each increment (increase) is twice the size of the last

• The worlds population has grown exponentially. This means that the rate of growth has been rapid.

• Between AD1 and AD1000 growth was slow

• In the last 1000 years it has been dramatic

• By 2000 there were 10 times as many people living as there had been 300 years before in 1700.

• Population is increasing and at a dramatic rate.

• Population grew especially between the late 20th and 21st century. Growth is predicted to continue but the rate it starting to slow down. It is likely to peak in 2150 at 10 billion and then there will be a more stable period of zero growth or even natural decrease.

• Population is shown as a line graph. Exponential growth produced a line which is very steep taking the shape of the letter J. Today growth rates are slowing down and the graph is levelling to make an S curve.

AD. 0

2000 Years Ago

At the dawn of the first millennium AD, the world’s population was around 300 million people

1000 years laterThe population had risen by as little as 10 million. Well into the 2nd millennium, it grew less than 0.1% each year. The numbers in Europe even fell in the 1300’s – struck down by the Black Plague. But beginning in the late 18th Century, the Industrial Revolution would raise living standards and spur growth.

AD. 1000

1800

One Billion

800 years laterThe population had climbed to the landmark level of one billion people. Almost 65% of all people lived in Asia, 21% in a prospering Europe, and less than 1\5 in North America

127 years laterThe two-billionth baby was born. From 1920 to 1950, the population growth rate hovered around 1% a year. But beginning in the middle of the century, the advent of antibiotics and other public health advances profoundly altered life expectancy, increasing the number of children who would live to bear their own children.

1927

Two Billion

1960

Three Billion

33 years laterAdvances in medicine, agriculture and sanitation had spread to many places in the developing world. By 1960, the global population reached 3 billion, and in the later 1960’s the growth rate hit an all time peak of 2.04% a year.

14 years laterNew reproductive technologies helped curb the birth rate (eg contraception). But with so many people already on the planet, a population “explosion” was under way, and the epicentres of the explosion lay in the developing world. The fourth-billionth baby was born in 1974.

1974

Four Billion

1987

Five Billion

13 years laterThe fifth-billionth baby was born

12 years laterAround October 12 1999, the six-billionth baby arrived. Today, Europe and Africa each hold about 12% of the world’s population. 9% live in Latin America, 5% in North America. Just as in 1800, Asia is home to the majority of Earth’s inhabitants – roughly 61% or more than 3.5% billion people.

1999

6 Billion

Roughly 40 years from nowOver the next 40 years, our numbers will increase again, likely to a staggering nine billion people. Nearly all of this growth will take place in developing countries, where the demand for food and water already outstrips supplies

2050

Nine Billion

Take a double page in your book and stick your graph in the middle

1. On your graph add labels in the correct place that help to explain the reasons for population growth.

- Use the information from your population history sheet to help add detail eg Black Plague in Europe in 1300’s

2. Add detail to your labels… try to EXPLAIN (think of reasons) WHY these events in history might have caused a change in population growth.

3. Describe the graph in detail.

Industrial Revolution (18th Centuary – 1760’s)

Christian era began (About 2000 years ago when Christians believe Christ was on Earth)

Dawn of the 1st Millennium (2000 years ago) pop = 300M

Add these labels too:

Logarithmic graphs

• Drawn onto special logarithmic graph paper.• Two types of log graph paper

-Logarithmic have logarithmic scales on both axes- Semi-logarithmic have a log scale on the y axis but a normal scale on the x axis.

• Semi log graphs are used to interpret data showing changes through time. It is useful for showing a range of values.• The scale on the y axis consists of a series of cycles. Each cycle is numbered 1-9. The distance between the lines decreases with distance from the bottom left hand corner of the graph. • You number the cycle by adding noughts to the printed numbers.

The Official ‘‘7 Billionth’’ baby

Danica Camacho Born in the Philippines. She weighed 5.5lbShe was chosen by the United Nations to symbolise the Global Population MilestoneShe was born in Manilla’s Jose Fabella Memorial HospitalBBC News - 'Seven billionth' baby is born

7 Billion: Where do you stand?

7th billion babyA good thing?

What are your concerns about population now?

What will happen to population in the

future?

What problems do you think will exist?

1. In groups, take it in turns to write a

response.

2. Pass around the page, everyone

must write something

down.

AllWrite RoundRo

bin

Feedback

So… what did you think?

A volunteer to record ideas on

the board, please!

Your task: Complete the two worksheets looking at population change today.

Here is a general outlook on how Medc’s and Ledc’s have changed through the years. As you can see Ledc’s have majorly contributed to the worlds overall population and has increased by more than double since 1950 to now. Also We can tell that Medc’s have pretty much stayed the same over the years meaning that they have not contributed to an increase in population majorly. Additionally if we look in the future this trend is expected to carry on with even bigger population increase for Ledc’s to come!

If we now look at this more in depth graph we can pretty much see a trend that everywhere is increasing its population but in different majorities, with the exception of Europe. We can see that areas like Asia and Africa are the two main contributors to world population due to them needing to develop. Other areas like Latin America, Caribbean and north America also show and increase but not as majorly and with not as many people. On the other hand Europe actually have a decreasing population due to it being very developed meaning a lower birth rate and death rate which results in an ageing population.

Future Projections

• By 2050, the world population is expected to reach 10 billion.

• United Nations expect that by this time, 90% of people will live in a developing country.

• Europe and Japan’s population is expected to fall sharply due to birth rate falling below the replacement level.

• The number of Britons over the age of 85 is expected to double to 2 million over the next 10 years.

• India is expected to overtake China as the leading country in terms of population

Your task: Using the graph above answer the questions on the sheet.

Home learning

Cartoons relating to population issues.

What is the message?

Your task: Complete the worksheet on population change

1a) Plot a line graph using the following population data (Use the millions data)

Year Population (million)

Population

(billion)

1100 500 0.5

1650 750 0.75

1820 1000 1

1930 2000 2

1960 3000 3

1974 4000 4

1987 5000 5

2000 6000 6b) Add arrows and the following labels to your line graphSlow population growthPopulation ExplosionRapid population growth2. Describe the growth in population from a)1100 to 1650b)1650 to 1930c)1930 to 2000Extra Task3. Calculate the population increase per year between each of the dates and comment on the rate of population increase.

You need to really think about the SCALE. If

you just put the dates equally

spread it will give you an

untrue graph shape.

World Population Growth

In October 1999, the world population officially reached 6 billion. Then just 12 years the 7 billion landmark was reached.

Why has population increased so much?Improved Health CareDevelopment of AgricultureAdvances in Medicine and HygieneTechnological ImprovementsBecause of a lack of education, people in Developing countries are unaware of contraceptionPeople want children to help with their current business in the future (often in the Developing World, for farmers etc)