Population change, migration and growth impacts
Explain how births, deaths and migration change population size and assess how population growth can affect settlements, resources, services, pollution and employment.
Section Paper 1 · Principles of Environmental Management
This original StudyForA sequence supports Cambridge IGCSE Environmental Management 0680 Topics 1–4 for exams in 2027, 2028 and 2029. Named local examples are chosen by the learner and centre; verify current conditions and local context with reliable sources. It is not a Cambridge paper, official grade or complete course.
Before you begin
- Use the 2027–2029 syllabus and check your exam year and centre's entry arrangements. Topics 1–4 are taught on this page; Topics 5–7 are still being built.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
Which factor can change a population's size?
What you will learn
- Explain how births, deaths and migration change population size and assess how population growth can affect settlements, resources, services, pollution and employment.
- Use evidence from an unfamiliar case to compare options and justify a context-sensitive judgement.
Explain factors affecting population change
Birth rates can be described as children per woman; death rates relate to life expectancy. Immigration adds people to a place and emigration removes them. Push and pull factors can influence migration.
Rural-to-urban and urban-to-rural movement are types of internal migration, while urbanisation describes an increasing share or number of people living in urban areas. A population changes through several factors rather than growth alone.
Trace impacts of population growth
Growth can contribute to informal urban settlements and megacities and affect availability of resources, energy use, sanitation, water supply, waste management, land, facilities and infrastructure.
Other possible impacts include air, land, light, noise, visual and water pollution, traffic congestion and changes in employment opportunities. Growth may create demand and economic activity as well as pressure; outcomes depend on planning, investment, governance and distribution.
Use evidence to explain outcomes
A larger population does not automatically cause a particular outcome. Link population change to the capacity of housing, transport, water, sanitation, land and employment systems.
Compare rates and access: a growing city with strong services may have different outcomes from one with limited infrastructure. Separate the number of people from how resources and opportunities are distributed.
Sources for this lesson
Pause and explain
Which is a possible impact of population growth?
Worked example
A city grows through rural-to-urban migration and natural change. Explain two factors affecting its population and two possible service or environmental impacts.
Show the worked solution
- Birth rates, death rates and migration affect population change; migration may involve push and pull factors.
- Growth may increase demand for water, sanitation, energy, housing, waste services and transport.
- Possible outcomes include informal settlements, congestion or pollution, but the scale depends on infrastructure, planning and access.
Answer Birth, death and migration patterns shape population change. Growth can put pressure on services and environments, but outcomes depend on planning and resource distribution.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
A city receives more migrants from rural areas. Explain the difference between immigration and urbanisation and give one possible infrastructure pressure.
Give me a hint
One describes movement into an area; the other describes growth in the urban population or share.
Compare my reasoning
- Immigration is movement into a place from elsewhere.
- Rural-to-urban migration moves people from rural areas to a city and contributes to urbanisation.
- More residents may increase demand on water supply, sanitation, transport, housing or waste services.
Rural-to-urban migration can contribute to urbanisation, while immigration describes movement into a place. Service pressure depends on capacity and access.
Look for these in your work
- Terms distinguished
- Direction of migration correct
- Infrastructure impact linked
A megacity has traffic congestion, informal settlements and new employment opportunities. Explain why these outcomes can occur together and identify evidence for evaluating quality of life.
Give me a hint
Population change can increase demand while also expanding economic activity; measure who gains and who lacks services.
Compare my reasoning
- Rapid population growth can outpace housing, transport and service capacity, contributing to congestion and informal settlements.
- A larger workforce and market can also create new employment opportunities, though access may differ between groups.
- Compare travel times, housing safety, water and sanitation access, employment and income data across neighbourhoods and over time.
Growth can create both pressures and opportunities. Quality-of-life evidence should include services, safety, mobility and employment, disaggregated by place or group.
Look for these in your work
- Pressures explained
- Opportunity explained
- Multi-dimensional evidence proposed
Two cities grow at the same rate, but one invests in water, transport and waste systems. Predict one likely difference and explain how to test it fairly.
Give me a hint
Compare service capacity and outcomes, controlling for population and time period.
Compare my reasoning
- The city with better investment may have greater service capacity and fewer shortages or waste-management problems, though distribution still matters.
- Measure water access, travel times, waste collection and pollution in both cities.
- Use comparable neighbourhoods and the same time period, and account for income, geography, climate and population distribution.
Infrastructure investment may change how growth affects services, but outcomes need comparable local data and controls for other differences.
Look for these in your work
- Prediction is conditional
- Relevant service indicators named
- Comparison factors considered
Common mistakes
- Equating immigration with emigration
- Calling all rural-to-urban movement international migration
- Assuming population growth automatically causes poverty or pollution
- Ignoring changes in employment opportunities
What can you explain now?
What is emigration?
Compare with the explanation
Movement out of a place
The correct answer is “Movement out of a place”. The alternatives “Movement into a place” and “The number of people per km²” do not match the syllabus concept. Explain how births, deaths and migration change population size and assess how population growth can affect settlements, resources, services, pollution and employment.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
Explain population change through birth, death and migration, then assess growth impacts using service and access evidence.
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.