Impacts of Population Growth (Cambridge (CIE) IGCSE Environmental Management): Revision Note

Impacts of population growth on urban areas

• Human population growth increases the number of people living in a country or city over time

• As populations grow, pressure is placed on land, resources and services

• These impacts are most visible in rapidly growing urban areas, especially in low- and middle-income countries, but they also affect high-income countries

• Studying these impacts helps understand the challenges of planning, sustainability and quality of life

Informal urban settlements

• Informal urban settlements are areas where housing is built illegally

• They develop when rapid population growth and rural–urban migration increase demand for housing faster than cities can provide it

• Homes are often overcrowded and made from temporary materials

• Access to clean water, sanitation, electricity and healthcare is usually limited

• This increases health risks and vulnerability to hazards such as flooding or fire

Megacities

• Megacities are urban areas with a population of more than 10 million people

• Population growth causes cities to expand rapidly in size and population

• Megacities can create economic opportunities through jobs and trade

• However, they also face serious challenges such as congestion, pollution and pressure on services

• Managing transport, housing and waste becomes increasingly difficult

Impacts of population growth on resources

Availability of resources

• Population growth increases demand for food, water and raw materials

  • This can lead to resource shortages if supply cannot keep up with demand

• Higher water demand for drinking, sanitation, agriculture, and industry depletes freshwater sources and creates scarcity

• More people require more food, leading to agricultural expansion, deforestation, soil degradation, and habitat loss

• Increased need for construction materials, minerals, and consumer goods accelerates extraction and depletion

  • Habitat destruction and pollution from increased activity threaten ecosystems and species

• Competition for resources can increase inequality and conflict

Energy usage

• As the population grows, energy demand rises for homes, transport and industry

  • More people mean higher energy consumption for homes, transportation, and industry, requiring more power generation

• Higher energy use and industrial activity boost greenhouse gas emissions, exacerbating global warming

  • Existing energy grids and infrastructure struggle to keep pace with rapid population growth

• In some regions, energy shortages may limit development and the quality of life

  • Burdens on public services (health, education, housing) rise, potentially increasing unemployment and poverty, and conflict over scarce resources

Impacts of population growth on water, sanitation and waste

Water supply

• Population growth increases demand for clean and reliable water supplies

  • A larger population means more demand for drinking, cooking, and sanitation, as well as needs in farming and industry

  • This depletes local sources

• Overuse of rivers, reservoirs and aquifers can lead to water shortages

  • Over-extraction for growing populations and agriculture lowers water tables

• Water pollution further reduces the amount of safe drinking water

  • More sewage and runoff from urban areas contaminate rivers and groundwater with pathogens, chemicals, and heavy metals, reducing clean water availability

• Some areas experience conflict over access to water

Sanitation

• Rapid population growth increases demand for toilets and sewage systems

  • Poor sanitation, including open defecation, spreads diseases by contaminating water and soil

• In many cities, sanitation infrastructure cannot expand fast enough

  • Existing sewage systems can't handle increased wastewater, leading to overflowing sewers and inadequate treatment

• Poor sanitation increases the spread of disease and is a major issue in informal settlements

Management of waste

• More people produce more solid waste and sewage

• Waste collection systems may become overwhelmed

• Inadequate landfill facilities lead to open dumping, polluting land and water

• Concentrated waste in growing cities creates localised air, water, and soil pollution

• This creates health risks and damages ecosystems

Impacts of population growth on land and infrastructure

Availability of land

• Growing populations increase demand for land for housing, industry and transport

  • Land prices may rise, making housing less affordable

• Forests are cleared for farmland, housing, and urban development, destroying ecosystems and reducing biodiversity

• Urban sprawl spreads cities into surrounding rural areas

  • This can lead to loss of farmland and fragmentation of habitats and loss of green spaces

• More land is needed for crops and livestock, leading to soil erosion and water pollution

  • Increased demand depletes natural resources like water, minerals, and fertile soil, contributing to land degradation and desertification

Facilities and infrastructure

• Population growth increases pressure on schools, hospitals, roads and public transport

  • Overcrowding leads to congested roads, inefficient public transport, and the need for costly new roads and railways

• If infrastructure development does not keep pace, service quality declines

  • Water supply, sewage systems, and energy grids become inadequate, leading to breakdowns, shortages, and increased pollution

• Overcrowded schools and hospitals reduce access to education and healthcare

  • Shortages force people into slums or informal settlements with poor sanitation, while straining hospitals, schools, and other public services

• Well-planned investment can improve living standards, but requires high costs

  • Existing infrastructure needs costly upgrades to withstand climate impacts like rising sea levels and extreme weather

Impacts of population growth on the environment

Pollution

• Population growth increases different types of pollution

• Air pollution rises due to traffic, industry and energy use

• Water pollution increases from sewage and industrial waste

• Land pollution results from landfill and unmanaged waste

• Noise and light pollution increase in densely populated urban areas

• Visual pollution reduces environmental quality and affects well-being

Traffic congestion

• More people lead to more vehicles on the roads

• Traffic congestion increases journey times and fuel use

• This contributes to air and noise pollution

• Productivity may fall as workers spend longer travelling

Impacts of population growth on employment opportunities

• Population growth boosts the labour force, but low-skilled workers may see lower wages

• It can boost demand for goods/services (creating jobs in sectors like construction, healthcare, tech)

• It can increase competition where more people compete for fewer jobs, raising the bar for applicants

• In some regions, unemployment and underemployment increase

• Young workers entering the market can outnumber job creation, causing high youth unemployment

• Informal employment may grow, often with low pay and poor working conditions

• In contrast, population growth can support economic growth if managed effectively