Changes in Population Size » Migration Factors and Patterns

What you'll learn this session

Study time: 30 minutes

The definition and types of migration
Push and pull factors influencing migration decisions
Global migration patterns and trends
Environmental causes and impacts of migration
Case studies of migration in different regions
How migration affects population distribution

Introduction to Migration

Migration is one of the key factors that influences population change alongside birth and death rates. When people move from one place to another, it can dramatically alter population sizes in both the origin and destination areas. Understanding migration helps us make sense of how human populations respond to environmental, economic, social and political pressures.

Key Definitions:

Migration: The movement of people from one place to another with the intention of settling temporarily or permanently in the new location.
Immigration: The movement of people into a country or area.
Emigration: The movement of people out of a country or area.
Net migration: The difference between immigration and emigration (can be positive or negative).
Internal migration: Movement within a country (e.g., rural to urban).
International migration: Movement between different countries.
Voluntary migration: People choose to move for better opportunities.
Forced migration: People are compelled to move due to conflict, persecution, or environmental disasters.

👈 Push Factors

Conditions that drive people away from their homes:

Environmental: Natural disasters, drought, climate change
Economic: Unemployment, low wages, poverty
Social: Poor healthcare, limited education
Political: War, persecution, corruption

👉 Pull Factors

Attractions that draw people to new locations:

Environmental: Better climate, fertile land, clean water
Economic: Job opportunities, higher wages
Social: Better healthcare, education, family connections
Political: Safety, freedom, democracy

Global Migration Patterns

Migration patterns have changed throughout history, influenced by technological advances, economic development, political changes and environmental conditions. Today, we see several distinct patterns emerging around the world.

Major Migration Corridors

The largest flows of migrants tend to follow specific routes or corridors around the world:

Mexico to USA: Primarily economic migrants seeking better wages and opportunities
North Africa to Europe: Mix of economic migrants and refugees crossing the Mediterranean
South Asia to the Gulf States: Labour migrants working in construction and service sectors
Rural to urban migration: Occurring within many developing countries as people seek urban opportunities

Case Study: Syrian Refugee Crisis

Since 2011, the Syrian civil war has forced over 6.8 million people to flee the country, creating one of the largest refugee crises in recent history. Most Syrian refugees initially moved to neighbouring countries:

Turkey hosts 3.6 million Syrian refugees
Lebanon hosts 1.5 million (increasing its population by nearly 25%)
Jordan hosts 1.3 million

This massive population movement has created environmental challenges including increased pressure on water resources, waste management issues and land use changes in host countries. It demonstrates how political factors can trigger large-scale migration with significant environmental consequences.

Environmental Causes of Migration

Environmental factors are becoming increasingly important drivers of migration worldwide. These can be sudden disasters or slow-onset changes that gradually make areas less habitable.

🌪 Sudden Events

Rapid-onset disasters that force immediate evacuation:

Floods
Hurricanes/cyclones
Earthquakes
Volcanic eruptions
Tsunamis

⏳ Slow-Onset Changes

Gradual environmental changes that make areas less habitable:

Sea level rise
Desertification
Land degradation
Deforestation
Water scarcity

🌐 Climate Change Impacts

How climate change is influencing migration:

More frequent extreme weather
Changing rainfall patterns
Agricultural disruption
Coastal erosion
Loss of biodiversity

Environmental Impacts of Migration

When large numbers of people move, they inevitably affect the environment in both the places they leave and the places they settle. These impacts can be both positive and negative.

🔃 Impacts in Source Regions

Environmental changes in areas people leave:

Positive: Reduced pressure on local resources, land recovery
Negative: Loss of traditional environmental management, abandoned infrastructure
Example: In parts of Nepal, out-migration has led to agricultural land being abandoned, allowing forest regrowth but also increasing landslide risks due to lack of terrace maintenance

🔄 Impacts in Destination Regions

Environmental changes in areas people move to:

Positive: New skills and knowledge, investment in sustainable practices
Negative: Increased resource consumption, pollution, urban sprawl
Example: Rapid growth of informal settlements around Nairobi, Kenya has led to water pollution, waste management challenges and deforestation

Case Study: Environmental Migration in Bangladesh

Bangladesh is one of the world's most vulnerable countries to climate change and environmental migration:

Each year, approximately 700,000 Bangladeshis are displaced by natural disasters
Rising sea levels threaten to displace up to 18 million people in coastal areas
Seasonal migration has become a survival strategy for many rural families affected by flooding
Dhaka, the capital city, receives 400,000-500,000 migrants annually, many fleeing environmental problems
This has led to rapid urbanisation with 40% of Dhaka's 18 million residents living in informal settlements

The Bangladesh example shows how environmental factors can drive large-scale migration, creating challenges for urban planning and resource management.

Migration and Population Distribution

Migration significantly shapes how populations are distributed across landscapes. It can lead to concentration in some areas and depopulation in others, with important environmental consequences.

Urbanisation and Rural Depopulation

One of the most significant migration trends globally is the movement from rural to urban areas:

In 1950, 30% of the world's population lived in urban areas
By 2018, this had increased to 55%
Projections suggest 68% of people will live in urban areas by 2050
This shift creates environmental challenges in cities (waste, pollution, resource demand) while rural areas face issues like agricultural land abandonment

Managing Migration

As environmental factors increasingly drive migration, governments and international organisations are developing strategies to address these movements:

Adaptation strategies: Helping vulnerable communities adapt to environmental changes to reduce the need for migration
Planned relocation: Organised movement of communities from high-risk areas
Disaster risk reduction: Improving early warning systems and emergency responses
International cooperation: Developing frameworks to protect environmental migrants who don't qualify as refugees under current definitions

Thinking Point: Migration as Adaptation

Rather than seeing migration only as a failure to adapt to environmental changes, many experts now view migration itself as an adaptation strategy. When people move in response to environmental pressures, they may be making rational decisions to protect their livelihoods and wellbeing. This perspective shifts the focus from preventing migration to managing it effectively and ensuring migrants' rights are protected.

Question to consider: In what ways might migration be a positive response to environmental challenges?

Summary: Key Points About Migration

Migration is a major factor in population change alongside births and deaths
People migrate due to a combination of push and pull factors, including environmental ones
Environmental causes of migration include both sudden disasters and slow-onset changes
Migration has environmental impacts in both source and destination regions
Climate change is likely to increase environmental migration in coming decades
Managing migration effectively requires international cooperation and recognition of migrants' rights

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