2. Human population

Human Impacts on Earth

• Environmental degradation occurs due to human actions.

• Waste generation impacts Earth's natural capital.

Human Population Growth

• Demographers consider three important trends:

  • Current size.

  • Growth rate.

  • Distribution.

• The population growth rate has slowed since 1965 but is still growing at 1.2%.

• Population is unevenly distributed; LDCs account for 96% of the 91 million added to the world’s population.

• Population growth rate in LDCs is faster than in DCs between 2018 and 2050.

Population Change

• Population can grow, decline, or stabilize.

• Birth > death: population increase.

• Death > birth: population decrease.

• Birth = death: stable population.

• Population change factors:

  • Birth (fertility).

  • Death (mortality).

  • Migration.

Calculating Population Change

• Population change = (birth + immigration) - (death + emigration)

• If (birth + immigration) > (death + emigration), population increases.

Fertility Rates

• Total Fertility Rate (TFR) affects population growth.

• TFR is the number of children born to women of childbearing age.

• From 1955 to 2016, TFR decreased from 5 to 2.5.

• A TFR of 2.1 is needed to replace both parents, considering infant mortality.

• Africa's TFR of 4.7 contributes to higher population growth, estimated to increase from 1.2 to 2.5 billion between 2016 and 2050.

Age Structure and Population Growth

• Age structure: percentages of males and females in young, middle, and older age groups.

• Important factor in determining TFR.

• Age categories:

  • Pre-reproductive: 0-14 ages.

  • Reproductive: 15-44 ages.

  • Post-reproductive: 45+ ages.

Slowing Human Population Growth

• 1. Economic Development:

  • Slows population growth.

  • Reduces degradation.

  • Reduces poverty.

  • Industrialized DCs during the 19th century show that increased per-capita income, poverty decline, and population growth tend to slow.

• 2. Educating and Empowering Women

  • Educated women have fewer children.

  • Control their TFR.

  • Earn their own income.

• 3. Family Planning

  • Education and clinical services help couples choose the number and timing of children.

  • Includes information on birth spacing, birth control, and healthcare for pregnant women and infants.