Human Population Growth; Past, Present, and Future Applying the principles of population dynamics and sustainability to the growth of the human population

World’s 10 Most Populated Countries

Population projections For the next 20 years

Population Growth by Continents

Current Population Trends World population = 7.35 billion (6,400,000) in 2017 More than doubled since 1963 = 3.2 billion In 2050 could be 9 – 10.6 billion Amplifies all environmental problems Largest increase expected in developing countries (approximately 97%) Decreasing in some developed countries Rate actually decreased between 1963-2004, but the population has still doubled from 3.2 –6.4 billion

Factors Affecting Human Population Size Population change equation Population change = (Births + Immigration) – (Deaths + Emigration) Crude birth rate = births per 1000 people in population per year Crude death rate = deaths per 1000 people in population per year

Varies between regions Total Fertility Rate (TFR) - Number of children a woman has during her lifetime, averaged for population. same as biotic potential (r) Replacement Level Fertility - Number of children needed to replace everyone in the population. Varies between regions 2.1 with low infant mortality 2.5 with high infant mortality Zero Population Growth - Birth rate equals death rate.

Sex Ratio - Age Distribution Sex Ratio- Relative number of males and females in a population Age Distribution - Number of individuals of each age in a population Together they tell how a population will grow

Population Age Structure Developing Countries Developed Countries Growth is determined by teenagers – the population wave of the future. 30% of pop’n <15 years = 1.9 billion more into reproductive years.

Population Trend Comparisons Developed Countries Low infant mortality rate Life expectancy 77 years Total fertility rate = 2.0 21% population <15 12% population >65 Per capita GDP = $36,110 Developing Countries High infant mortality rate Life expectancy 52 years Total fertility rate = 5.7 44% population <15 3% population >65 Per capita GDP = $800

Human Population Issue Several factors determine the impact of a society on natural resources. Population size Population density Degree of technological development Demography - Study of populations and their characteristics. Larger ecological footprint in U.S. than in developing countries. Why?

Factors Affecting Birth Rates and Total Fertility Rates Children in Labor Force Cost of raising and educating children Availability of pension systems Urbanization Education and employment for women Infant mortality rate Average marrying age Abortion Availability of birth control

Major social factor determining family size is the role of women in society. Early marriages foster high fertility rates. Lack of education opportunities for women reduces their options. When level of education increases, fertility rates fall. The most important factor is the ability of women to control the size of their family. Access to birth control is key.

United States Population Picture US population has a post-war baby boom period, significantly affecting pop. trends. 20 yr period following WWII By 2030, 20% of US pop will be over 65

Demographic Transition As countries become industrialized, death rates, then birth rates decline.

Overpopulation Concerns

Global Megacities Number of large cities growing. World’s urban population will increase from 3.1 billion to 5 billion from 2004-2030.

US metropolitan areas

Undesirable Impacts of Urban Sprawl

Loss of crop land, forest land, and wetlands

Fragmenting fish and wildlife habitats

Increased impervious surfaces means more flooding

And soil erosion

Environmental Impact

Growth Management Act 1990 The GMA requires state and local governments to manage Washington’s growth by identifying and protecting critical areas and natural resource lands, designating urban growth areas, preparing comprehensive plans and implementing them through capital investments and development regulations. GMA is passed to help protect areas critical for natural resources by concentrating growth in urban areas

And a larger ecological footprint

Cutting Global Population Growth Family planning Improve health care Elevate the status of women Increase education Involve men in parenting Reduce poverty Sustainability

Population Control SMALL GROUP ACTIVITY-- Debate: Should abortion be used as a means to control population growth? Why or why not? Explain your answer in a one page essay. Use research to quote sources and argue your point of view on this subject.

Review Questions What are the world’s ten most populated countries? For the year 2025, what are the population projections for China, India, and the USA? Which continent will experience the largest population growth? Which continent will experience the least growth? As of 2017, what is the population of the whole world? What are some factors that affect population growth?

Review Questions (continued) 6. What is sex ratio? 7. What is age distribution? 8. What are some countries that have rapid population growth? What are some countries that have slow population growth? 9. What is the major social factor determining family size? What are three factors that determine the impact of a society on natural resources? List nine factors that affect birth rates and total fertility rates.

Review Questions (continued) What are five social factors determining family size in society? By the year 2030, how much of the U.S. population will be over 65 years old? What is demography? Name five of the world’s Megacities. How much will the world’s urban population increase from 2004 to 2030? What is the Growth Management Act of 1990? What are some ways to cut global population growth?