Introduction: Understanding the Human Squeeze

As the number of people on our planet increases, the environment and our social systems feel the "squeeze." This chapter explores what happens when population growth happens faster than a country can keep up with. Think of it like a bus built for 40 people that suddenly has 80 people trying to get on—everything from the seats to the air quality becomes a problem!

We will focus on how this growth affects where people live, the resources they use, and the waste they produce.

1. Megacities and Informal Settlements

Rapid population growth, often caused by urbanisation (people moving from the countryside to cities), leads to major changes in where humans live.

Megacities

A megacity is a very large city, typically with a population of over 10 million people. While they offer opportunities for jobs, they often struggle with overcrowding and massive demand for services.

Informal Settlements

When cities grow too fast, there isn't enough affordable housing for everyone. This leads to the creation of informal settlements (sometimes called slums or shanty towns). These are areas where:

  • Housing is built on land that the residents do not own.
  • Buildings are made from scrap materials like plastic, tin, or wood.
  • There is often no legal access to electricity or clean water.

Key Takeaway: Rapid growth often outpaces the government's ability to build houses, forcing people into crowded, unofficial living areas.

2. Pressure on Resources

Every person needs resources to survive. When the population grows, the demand for these resources can lead to scarcity (not having enough).

  • Food: More people mean more mouths to feed. This can lead to over-farming, which exhausts the nutrients in the soil.
  • Water: Fresh water is limited. High demand can lead to water stress and the depletion of aquifers (underground water stores).
  • Land: More space is needed for houses and roads, which often means cutting down forests or using up good farming land.
  • Energy: Demand for electricity and fuel (for cooking and transport) increases, leading to faster depletion of finite resources like fossil fuels.

3. Infrastructure and Services

Infrastructure refers to the basic physical systems of a country. Population growth puts immense pressure on:

  • Transport: More people mean more cars and buses, leading to severe traffic congestion and longer travel times.
  • Healthcare: Hospitals and clinics become overcrowded, and there may not be enough doctors or medicine for everyone.
  • Education: Schools may have too many students per classroom, making it harder for children to learn.
  • Utilities: Systems for providing electricity and clean water often break down because they weren't designed to handle so many users.

Don’t worry if this seems like a lot to remember! Just think: "What does a person need every day?" (A house, a school, a doctor, a bus). If there are too many people, all those things become harder to get.

4. Sanitation and Waste

One of the biggest impacts of a growing population is the massive amount of waste produced.

Sanitation

Sanitation is the system for disposing of human waste (sewage) safely. In overcrowded areas or informal settlements, there may be no proper toilets or sewers. This is dangerous because:

  • Waste can leak into drinking water.
  • It increases the risk of water-related diseases like cholera.

Waste Management

More people create more domestic waste (household rubbish) and plastic waste. If a city does not have enough garbage trucks or landfill sites, waste builds up in the streets. This can block drains (causing floods) and attract pests like rats that spread disease.

5. Pollution

Population growth is directly linked to increased pollution in several ways:

  • Air Pollution: More people mean more vehicles and more factories, releasing gases like carbon dioxide \(CO_2\) and nitrogen oxides into the atmosphere.
  • Water Pollution: Increased sewage and industrial chemicals are often dumped into rivers and oceans.
  • Visual Pollution: The buildup of litter and poorly planned buildings can damage the natural beauty of an area.

Did you know? High population density often leads to noise pollution, which can affect the health and sleep of people living in megacities.

6. Employment Change

A growing population means a growing workforce (people available to work). This has two sides:

  • Job Shortages: If the population grows faster than the economy, there aren't enough jobs for everyone, leading to high unemployment.
  • The Informal Economy: Many people end up working in "informal" jobs, such as street vending or casual labour. These jobs often have low pay, no contracts, and no safety protections.
  • Shifts in Industry: As countries move from LICs (Low-Income Countries) to MICs (Middle-Income Countries), the types of jobs change from farming (primary sector) to manufacturing and services.

Quick Review: Common Mistakes to Avoid

  • Mistake: Thinking "population density" and "population growth" are the same.
    Correction: Density is how many people live in \(1 \text{ km}^2\); growth is the increase in the number of people over time.
  • Mistake: Using the terms MEDC or LEDC.
    Correction: The current syllabus uses HIC (High-Income Country), MIC (Middle-Income), and LIC (Low-Income).
  • Mistake: Forgetting that growth can happen in HICs too.
    Correction: While growth is usually faster in LICs, HICs also face impacts like traffic congestion and housing shortages.

Summary Table: Impacts of Growth

Issue: Housing
Impact: Rise of megacities and informal settlements.

Issue: Health
Impact: Poor sanitation leads to diseases like cholera; overcrowded hospitals.

Issue: Environment
Impact: Increased pollution (air, water, land) and loss of natural habitats.

Issue: Economy
Impact: Pressure on jobs and a rise in the informal workforce.