Impacts of Population Growth (Cambridge International IGCSE Environmental Management)

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

Exam Hint Always link population growth to pressure on resources and services.

Avoid listing impacts without an explanation.

Use clear cause-and-effect chains.

To achieve higher marks, be sure to include both the social and environmental impacts.