Topic 8: Human populations and urban systems

• Births and immigration • Crude birth rate, immigration rate

• Deaths and emigration are outputs from a human population • Crude death rate (number of deaths per 1,000 people in a population per year) and emigration rate (number of emigrants per 1 • The rates can be used at a variety of scales—from small urban areas, like a town, to a country to a region or to the global population

• Population dynamics can be quantified and analysed by calculating total fertility rate, life expectancy, doubling time and natural increase • Total fertility rate is the average number of births per woman of childbearing age • Life expectancy is the average number of years that a person can be expected to live, usually from birth, if demographic factors remain unchanged • Doubling time is the number of years it would take a population to double its size at its current growth rate; it can be calculated by using the rule of 70

• The global human population has followed a rapid growth curve • Models are used to predict the growth of the future global human population • UN projection models indicate three scenarios linked to future fertility rates • There is uncertainty about how future human fertility rates may change, leading to the three scenarios in the models

• Population and migration policies can be employed to directly manage growth rates of human populations • These may be anti-natalist or pro-natalist, thereby directly addressing birth rates, or they may address immigration and emigration • These policies may use a variety of cultural, religious, economic, social and political factors to achieve their aims • Include: named examples

• Human population growth can also be managed indirectly through economic, social, health, development and other policies that have an impact on births, deaths or migration • Many development policies addressing areas such as, but not limited to, gender equality, education, improvements in public health and welfare will indirectly affect births • Include: two named examples

• The composition of human populations can be modelled and compared using age–sex pyramids • The pyramid is measured in absolute numbers or as a percentage of the total population • It shows the proportion of the population of either gender in each age group

• DTM describes changing birth and death rates through stages of development • Used to analyse population change over time

• Increased stress on Earth's systems • Related to biocapacity disparity and planetary boundaries

• Determine dependency ratio and population momentum • Dependency ratio: dependent ages vs. productive ages (15-64) • Population momentum: growth continues despite fertility decline

• Compare countries in different DTM stages • Historical, cultural, religious, economic, social, political factors

• Climate change, drought, land degradation • Sudden onset: flooding, fires, storms • Slow onset: desertification, sea-level rise, saltwater inundation

• Biotic components: plants, animals, life forms • Abiotic components: soil, water, air, climate, topography

• Built-up area with high population density • Buildings and infrastructure • Cities, towns, suburbs

• Buildings, microclimate, transport, goods/services • Power/energy, water/sewage, humans, plants, animals

• Population shift from rural to urban areas • Land becomes more built-up and industrialized

• Greater proportion now live in urban systems • Push-pull factors, forced vs. voluntary

• Movement from dense central to lower-density peripheral areas • Urban sprawl

• Loss of agricultural land, forests, ecosystems • Water quality changes, river flow changes, air pollution

• Decide best land and building use • Meet stakeholder needs: physical, domestic, environmental, commercial

• Quality housing, public transport, green spaces • Renewable resources, waste recycling, energy efficiency

• Treats urban system as ecosystem • Urban ecology: green spaces, wildlife habitats • Urban farming: beekeeping, horticulture, city farms • Biophilic design: green walls/roofs, water features, natural light • Resilience planning: vertical farming, flood-adaptive building • Regenerative architecture: air-scrubbing building skins, energy export

• Urban compactness, mixed land use, social mix • Reduced sprawl, less car dependency, better transport • Increased accessibility and social equality

• Circular economy, doughnut economics • Promote sustainability within urban system

• Minimizes harmful construction effects • Environmentally friendly materials and practices • Combines indigenous knowledge, bio-based materials, circular construction

• NOx, sulfur dioxide, carbon monoxide, particulate matter • PM2.5 (≤2.5 µm), PM10 (≤10 µm)

• Natural: forest fires, dust, volcanic eruptions • Anthropogenic: burning for clearance, fossil fuels, construction dust

• Most common urban air pollutants • Primary: PM2.5, PM10, CO, SO₂ • Secondary: tropospheric ozone

• Public transportation, cycling infrastructure, trees • Green walls, catalytic converters, pedestrianized areas

• NOx + SO₂ react with water and oxygen • Produces nitric and sulfuric acid

• Terrestrial: soil leaching, toxification, foliage damage • Freshwater: toxicity, impacts on fish/invertebrates • Buildings: corrosion of marble, limestone, steel • Human health: tissue damage, lung inflammation

• Alter human activity (alternative energy) • Control at release (scrubbers, catalytic converters) • Restore damaged systems (healthcare, lake treatment)

• Sunlight acts on primary pollutants → secondary pollutants • Primary: NOx, VOCs • Secondary: PANs, tropospheric ozone

• Meteorological: abundant insolation, reduced wind, temperature inversion • Topographical: mountains, high buildings

• Biological: plant damage, eye irritation, respiratory illnesses • Physical: fabric and rubber damage

• Societal costs, lost economic output • Healthcare system impacts, reduced workforce • Disproportionate impact on poorer communities

HL.a.1—Laws definition

• Rules governing human behaviour • Enforced by social or governmental authority

HL.a.2—Environmental law

• Rules on natural resource use and impact • Aims: improve social and ecological sustainability • Covers: resource management, pollution, biodiversity, development projects

HL.a.3—Environmental justice and lobbying

• Can address environmental justice • Difficult to approve due to lobbying • Prevent overexploitation for short-term minority interests

HL.a.4—Environmental law frameworks

• Built into existing legal frameworks • Success varies by country • Requires: enforcement, social acceptance, adequate funding

HL.a.5—Environmental constitutionalism

• Environmental rights/obligations in constitution • Growing internationally • Addresses climate change issues

HL.a.6—Environmental law levels

• Local, national, international • Higher levels supersede lower levels • Examples at each scale

HL.a.7—International law framework

• Addresses transboundary issues • Pollution and resource management • Examples: ASEAN Haze Pollution, FAO fishing plan

HL.a.8—UN conventions and protocols

• Legally binding to signatories • Challenging and slow to develop • Examples: Montreal Protocol, Kyoto Protocol, Paris Agreement

HL.a.9—International institutions

• Generated by international agreements • Aid implementation • Examples: CITES, IUCN

HL.a.10—International courts and tribunals

• Apply international environmental law • Examples: International Court of Justice, Law of the Sea Tribunal • Challenge: evaluating compensation for infringements

HL.a.11—Legal personhood for nature

• Granting to natural entities • Strengthens environmental protection • Links to indigenous knowledge systems

HL.a.12—Legal and economic strategies

• Both play role in sustainable use • Integration provides best outcomes

• Studies production, distribution, consumption of goods/services • Supply and demand of resources

• Economics applied to environment and environmental issues • Technocentric vs. ecocentric perspectives

• Free market imposes negative environmental impacts • Example: factory pollution with no cost to polluter

• Costs of pollution covered by polluter • Solutions: quotas, fines, taxes, tradeable permits, certification

• Marketing as sustainable without changing practices • Example: oil companies claiming clean energy transition

• Unclear property rights → overexploitation • Limitation of free market economics • Alternative approaches: Ostrom's shared pastures

• Attach economic value to natural resources and depletion • Problematic to achieve consensus value

• Use value: can be established • Non-use value: intrinsic, future use, intergenerational • Estimated by willingness to pay or accept compensation

• Economy as subsystem of biosphere • Social system as subcomponent of ecology • Emphasizes sustainable use of natural capital

• Greater emphasis in ecological economics • "Resource depleted" countries pay "resource rich" to preserve • Creates tensions between countries

• Change in GDP (annual percentage) • Per capita GDP better for living standards assessment

• Influenced by supply and demand • Linear economy, doesn't account for waste/pollution

• Positive and negative effects • Can provide resources for protection or cause degradation • Raises environmental justice questions

• Separating economic growth from environmental degradation • Absolute decoupling likely impossible • Relative decoupling: reduced degradation

• Supports degrowth, zero growth, or slow growth • Planned reduction in consumption/production • Particularly in high-income countries

• Difficulties: dismantling embedded systems • Measuring social/environmental well-being • Balance ecological footprint with biocapacity

• Applications of ecological economics • Product stewardship • Address inequality and injustice

• Branch of philosophy • Moral principles, right and wrong behaviours

• Addresses environmental issues • Arose in 1960s-1970s • Western traditions inadequate for non-human entities

• From differing fundamental beliefs • Human-nature relationship • Ecocentric: nature has intrinsic and equal rights • Stewardship: human responsibility towards nature • Anthropocentric/technocentric: nature serves human needs

• Usefulness for humans • Goods, services, human development opportunities

• Value for what it is • Non-living: wild, culturally significant, beautiful • Living: organized for survival/reproduction

• Example: whales (aesthetic and tourist attraction)

• Should be morally considered • Ecocentrists: all living things (some include non-living) • Extends to future generations

• Virtue ethics: person's character • Consequentialist (utilitarian): action consequences • Rights-based (deontological): entity rights

• Good people do good actions • Respect, compassion, responsibility towards nature

• Consequences determine morality • Good consequences = good actions • Greatest common good

• Focus on actions conflicting with rights • Debate about what rights exist

• Whatever is natural is correct/good • Contentious position • Not all natural things are good (e.g., diseases)

• Developed from separate histories • Increasingly seeking common goals • Equitable and just societies