Human Systems and Resource Use 7Billion Chapter 8 Human Systems and Resource Use 7Billion

Is the World Overpopulated? The world’s human population was projected to increase from 6.6 Billion in 2006 to 9.2 Billion in 2050? What is the current population? In 2006, the population of developed countries grew 0.17% per year. Developing countries grew 1.4% per year. In 2010 99% of growth was in developing countries! Current average growth rate is 1.11% which is down from 1.13% in 2016

HUMAN POPULATION GROWTH: For most of history the human population grew slowly In the last 200 years humans have experienced exponential growth! Demographics: The study of the dynamics of population change

The Future? The High Variant: Crude death rate (CDR) continues to fall, while crude birth rate (CBR) falls more slowly The Low Variant: We will not find cures for diseases and CBR will decrease

3 Reasons for Rapid growth is past 200 years Ability to move into diverse habitats and new climate zones Improved agriculture allows more people to be fed Developed sanitation, antibiotics, and discovered concentrated energy sources (fossil fuels)

Factors Affecting Population Size crude birth rate (CBR): total number of births per 1,000 crude death rate (CDR): total number of deaths per 1,000 Calculated by dividing the number of births or deaths by the population size and multiplying by 1000 natural increase rate (NIR): Rate of growth expressed as percentage change each year (CBR-CDR)/10 (Migration is not accounted for) Doubling Time: 70/NIR

Babies!!! Total fertility rate (TFR) : ave. # of children women have. most useful for predicting future population change When was the TFR greatest in the U.S.? Baby boom = 3.7 at its highest point in 1957 Current TFR in USA is 1.87 (why aren’t we shrinking)? What about other countries?

More Babies!!! Replacement level fertility – # of children needed to replace parents What number do you think it should be? 2.0 in theory, but in MEDCs it is 2.03 and in LEDCs it is 2.16 and much higher in some. Why? Higher due to infant mortality Why do they die? Malnutrition

Global TFR

MEDCs and LEDCs Human Development Index (HDI) A measure of the “well-being” of a country Combines health, wealth, GDP, and education into one value.

Factors Affecting Birth and Fertility Rates The number of children women have is affected by: The cost of raising and educating them Having rights protected Education and employment opportunities Infant deaths Marriage age Availability of a pension Availability of contraception Availability of abortion

Human Population and Resources It is SIMPLE! More people = more resources More people = more waste People usually want “progress” More people = greater impact Sustainability? Sure we just have to control population increase and resource demand But how?

Survivorship Curves and Humans Think of it as showing the odds of surviving to a certain age! Type 1: Late Loss Shows most individuals surviving until old age (developed countries) Type 2: Constant Loss Shows that individuals have equal chance of dying at a young age (usually due to malnutrition or poor hygiene) Type 3: Early Loss Shows many individuals dying young (not usually seen with humans)