Human Population Growth Lesson

China’s One-Child Policy

• In 1970, the average Chinese woman had about six

children.

• Since 1979, China has used a system of rewards and

punishments to enforce a one-child limit to slow
population growth.

• In 2005, there were 32 million more males than

females in China under the age of 20.

Talk About It Is it ethical for governments to limit or
encourage human population growth?

Lesson 8.1 Trends in Human Population Growth

As of 2010, the human population
is 6.8 billion (and counting).

History of Human Population

Growth

• Advances in agriculture

and industry have led to
longer lifespans and
remarkable population
growth.

• Agriculture: Helped people

meet their nutritional needs;
increased free time to
pursue crafts and trading

• Industry: Improved

sanitation, medicine, and
food production

Did You Know? Basic sanitation was rare even in the medical
profession until 1861, when Dr. Ignaz Semmelweis discovered
that doctors’ hand washing greatly reduced patient mortality.

Lesson 8.1 Trends in Human Population Growth

Infant Mortality and Life

Expectancy

• Populations are likely to grow

when infant mortality is low and
life expectancy is high.

• Infant mortality: Number of babies

out of 1000 that die during their first
year of life

• Life expectancy: Average number

of years a person is expected to live

• Population growth rate describes

the change in population’s size
during a given period of time.

Lesson 8.1 Trends in Human Population Growth

Recent Trends in Human

Population Growth

• Growth rate of human

population has slowed from
2.1% to about 1.2% since
the 1960s.

• Population growth rates vary

by region. Some nations have
negative population growth
rates, meaning the population
is getting smaller.

• Humans use technology to

extend Earth’s carrying
capacity for our species.

Did You Know? To estimate how long
it would take any population to double,
divide 70 by its growth rate.

Lesson 8.1 Trends in Human Population Growth

Demography: Describing the

Human Population

• Population size:

Number of people

• Population density:

Number of people living
per mi2 (or per km2)

• Population

distribution: How
people are distributed
within an area

Lesson 8.1 Trends in Human Population Growth

Lesson 8.2 Predicting Population Growth

Some scientists predict
that there will be
9 billion people on
Earth by 2050, while
others maintain that the
population will be
closer to 10.5 billion.