L8 Human Population & Sustainability II Notes PDF

L8: Human Population & Sustainability II Dr. Cynthia Yau OCES1030 Environmental Science Image: Megacity around Beijing (City Journal) Lecture Outline Population Age Structure Diagrams Birth Rate, Death Rate & Rate of Natural Increase Fecundity vs Fert...

L8: Human Population & Sustainability II Dr. Cynthia Yau OCES1030 Environmental Science Image: Megacity around Beijing (City Journal) Lecture Outline Population Age Structure Diagrams Birth Rate, Death Rate & Rate of Natural Increase Fecundity vs Fertility, Total Fertility Rate China’s Population Growth The Demographic Transition Sustainability Calculating Environmental Impact of Human Population Ecological Footprints Population Growth Could Bring Benefits Reference: Cunningham & Cunningham, Chapter 4  Population Age Structure Diagrams Also called population pyramids - display the distribution of a population by sex and age. Y-axis: Ages Age (5-year increments, younger ages at the 80+ Male Female 75-79 bottom) 70-74 65-69 60-64 X-axis: Percentages (numbers) of males 55-59 50-54 and females in each age group 45-49 (males on left, females on right) 40-44 35-39 30-34 25-29 Overall shape 20-24 15-19 Indicator of future population 10-14 5-9 growth 0-4 Implications for socio-economy 300 200 100 0 100 200 300 Millions PRB  Population Pyramids Rapid growth Stable population Declining population  Human Population Growth: Age Structures Age Structures Populations of MDCs and LDCs can be divided into three age groups: Pre-reproductive Reproductive Post-reproductive MDCs and LDCs have different age structure diagrams Many MDCs have a stable age structure Most LDCs have a youthful profile and are experiencing rapid population growth 5 Rapid population increase Declining population Niger (Africa) Japan  Birth Rate, Death Rate & Rate of Natural Increase (Crude) Birth Rate = Number of births per 1000 people in a population in a given year (Crude) Death Rate = Number of deaths per 1000 people in a population in a given year Rate of Natural Increase = Birth Rate – Death Rate (estimated rate of population growth without regard for migration) Population birth death Other factors  Fecundity vs. Fertility Fecundity = The physical ability to reproduce Fertility = The actual number of children born to a woman Two Types of Fertility Data: 1. Replacement-Level Fertility - the level of fertility at which a couple has only enough children to replace themselves = an average of 2.1 children per woman 2. Total Fertility Rate - the average number of children that are born to a woman over her lifetime (varies with country). Total Fertility Rate Average number of children a woman will have during her child-bearing years (ages 15-49). Worldwide: 2.3 (more developed: 1.5; less developed: 2.4) Highest (6.7) ‒ Niger (Africa) Lowest (0.7) ‒ South Korea Other areas China (1.7) Hong Kong (0.9 – 1.4) India (2.1) U.S. (1.8) [TFR figures for 2023] Total Fertility Rate by Country Desire for larger families persist in Niger Factors Affecting Birth and Fertility Rates Biological, cultural and economic factors Examples Importance of children as a part of labor force Urbanization Educational and employment opportunities Infant (baby) mortality rate Average age at marriage Availability of reliable birth control methods Religion and culture Cost of raising and educating children  Chain’s Population Growth Enacted in 1979 by China’s Communist Party, the controversial “One Child Policy” was primarily meant to slow the country’s rapid population growth, while capping the growing drain on China’s limited resources. The Chinese government’s primary objectives were achieved through these extreme measures, but with unintended consequences Cultural preference for male children → China is skewing older and more male (gender imbalance) it is also losing its strong base of younger workers that could potentially support the rest of the population China will have a burgeoning elderly demographic of people born before 1979  Population of China 1950 2000 2050 Age Age 80+ 80+ 75-79 75-79 Male Female 70-74 Male Female 70-74 Male Female 65-69 65-69 60-64 60-64 55-59 55-59 50-54 50-54 45-49 45-49 40-44 40-44 35-39 35-39 30-34 30-34 25-29 25-29 20-24 20-24 15-19 15-19 10-14 10-14 5-9 5-9 0-4 0-4 15 10 5 0 5 10 15 15 10 5 0 5 10 15 15 10 5 0 5 10 15 Population (millions) Source: World Population Prospects: The 2004 Revision (2005). (PRB 2006) China’s Falling Birth Rate  One-child Policy 1979 Two-child Policy 2016 Three-child Policy 2021 By the year 2100, China will not be home to a single one of the world’s 20 most populous cities. Instead, these massive metropolises will almost exclusively be located in places like India and Africa – and some of them, like Mumbai (India), will hold 60 million or more inhabitants. There is optimism that increasing levels of automation and the emergence of artificial intelligence will help make up for any shortfalls in the Chinese workforce The World’s Craziest Population Pyramids https://www.youtube.com/watch?v=keUaC-oyXWU India currently ranks as the world’s most populous country with 1.45 billion (2024), overtaking China in 2023. Population Pyramids of China & HK China Hong Kong  The Demographic Transition: Five Stages A model that states “rapid population growth is a temporary phenomenon”  Sustainability In 1987, the United Nations Brundtland Commission defined sustainability as “meeting the needs of the present without compromising the ability of future generations to meet their own needs.” Sustainability or sustainable development is a central theme of environmental science and of human development and resource use. Use resources in sustainable ways - e.g. energy, water, land, wildlife, natural environment Resources should be preserved so that future generations can have lifestyles at least as healthy and happy as ours - or perhaps better  What Is Earth’s Carrying Capacity? The majority of studies estimate Earth’s K at or beneath 8 billion people (mid-2024 = 8.179 billion) 13  UN Sustainable Development Goals In 2015, the 193 Member States of the United Nations (UN) adopted The 2030 Agenda for Sustainable Development, which provides the blueprint for peace and prosperity for people and the planet, now and into the future, with 17 Sustainable Development Goals (SDGs) - a set of priorities for all countries… to act in collaborative partnership.  What are Hong Kong’s SusDev Goals? Goal #1: No Poverty Goal #2: Zero Hunger Goal #3: Good Health & Wellbeing Goal #4: Quality Education Goal #5: Gender Equality Goal #6: Clean Water & Sanitation Goal #7: Affordable & Clean Energy Goal #8: Decent Work & Economic Growth Goal #9: Industry, Innovation and Infrastructure Goal #10: Reduced Inequality Goal #11: Sustainable Cities and Communities Goal #12: Responsible Consumption & (2018) Production Goal #13: Climate Action Goal #14: Life Below Water Goal #15: Life on Land 3. Goal #6 - Clean Water & Sanitation Goal #16: Peace, Justice & Strong Institutions Goal #17: Partnerships to achieve the Goals 2. Goal #7 – Affordable & Clean Energy 1. Goal #13 – Climate Action  Calculating the Environmental Impact of Human Population Our environmental effects are not just a matter of population size; they also depend on what kinds of resources we use and how we use them. This concept is summarized by the formula: I = PAT I = environmental impacts P = population size A = affluence level T = technology level A family living an affluent lifestyle in the U.S. could cause greater environmental damage than a whole village of poor African gatherers. 23  Ecological Footprints Can Calculate Overall Resource Use Another way to estimate our environmental impacts is to express our consumption choices into the equivalent amount of land required to produce goods and services. This gives us a single number, called our ecological footprint - estimates the relative amount of productive land and water, etc. required to support each of us to produce the goods consumed, and to assimilate the wastes generated Ecological footprint is a useful tool to measure people’s natural resource consumption (sustainability). 24 Ecological Footprint (cont.) Represents demand for resources by adding up land and sea areas (global hectares, or gha) that are: 1. Required to provide ecological resources and services Crops, fish (plus other foods, fiber, biofuels) Timber Grass, grain (for feeding livestock) Global Hectare (gha) = The average productivity of all biologically productive areas (in hectares) on Earth in a given year e.g. biologically productive areas: cropland, forests, fishing grounds Ecological Footprint (cont.) 2. Occupied by infrastructure (built-up land footprint) Transportation Housing Industrial structures Reservoirs for hydropower 3. Required for absorbing wastes Land occupied by solid wastes or contaminated by pollutants CO2 emitted from burning fossil fuels Living Planet Report 2018  Urbanization-related Agricultural Land Loss in China (cont.) Shi et al. (2016) Ecological Footprint (cont.) Global ecological footprint changes with Population size Average consumption per person Resource efficiency (efficiency with which resources are turned into consumption products) A useful tool to measure people’s natural resource consumption (sustainability). Calculate your ecological footprint https://www.footprintcalculator.org/ home/en  Population Growth Could Bring Benefits Advantages of having more people in the world: larger markets more workers for the labour force better efficiencies of scale in mass production of goods more people to find new resources More people to innovate and find better solutions to problems. Economist Julian Simon (1990s) believed that people are the “ultimate resource” and said that “no evidence shows that pollution, crime, unemployment, crowding, the loss of species, or any other resource limitations will worsen with population growth”. What do you think?? 30  World Population Projections Different scenarios have been proposed Which trajectory will we follow? Source: World Population Prospects 2019 © 2019 United Nations. “Fewer people won’t save the planet, behaving better will” The Conversation, 2013 31