Natural and energy resources
A natural resource is something from nature that people use: water, soil, forests, minerals and fuels. Renewable resources (sun, wind, water, forests if managed well) come back. Non-renewable resources (coal, oil, natural gas) take millions of years to form, so they run out.
Energy resources run our homes, factories and vehicles. Fossil fuels give most of the world's energy today, but they release carbon dioxide and warm the planet. Wind, solar, hydro and other clean sources are growing fast.
Resources are spread unevenly. Some places have oil, some have fertile land, some have strong sun or wind, and some have little. Countries trade to fill the gaps, and the places with resources often grow rich. Using resources wisely (saving, reusing, switching to cleaner energy) is part of sustainable development.
Migration
Migration is the movement of people from one place to live in another, for a time or for good. It can be within a country (village to city) or between countries.
Reasons are grouped as:
- Push factors (they make you leave): no jobs, poverty, drought, war, natural disaster.
- Pull factors (they attract you): jobs, higher pay, schools, hospitals, safety.
A person is an emigrant from the place they leave and an immigrant to the place they reach. A person forced to leave because of danger is a refugee. Migration has gains (money sent home, new skills, new ideas) and costs (crowded cities, empty villages, hard lives for some migrants).
Demography
Demography is the study of population: how many people there are, how fast the number changes, and how old people are.
Three numbers matter most: the birth rate, the death rate and migration. Population change = births − deaths + (people who arrive − people who leave).
A population pyramid draws the number of people in each age group as bars. A wide base means many children and fast growth. A narrow base with a wide top means an ageing population. Migration changes the pyramid too: young workers leave villages and arrive in cities.
Climate and economy
Climate is the usual weather of a place over many years. It decides which crops grow, how much water is there, and what energy a place can use (sun, wind, hydro).
When the climate changes (more heat, drought, floods, rising sea level), incomes fall in farming, fishing and tourism, and costs rise for repairs and food. People may move to places with better chances. This is climate-driven migration.
The economy and climate also push each other. Burning fossil fuels builds the economy but heats the planet. Clean energy, saving water and better farming can cut this harm and still keep jobs.
Key formulas and definitions
- Population change = births − deaths + immigrants − emigrants
- Natural increase = births − deaths
- Net migration = people arriving − people leaving
- Migration pressure grows with push (poor rain, no work) and pull (jobs in the city)
Worked examples
1. In one year a region has 12,000 births, 9,000 deaths, 5,000 people arriving and 8,000 leaving. What is its population change?
Natural increase = 12,000 − 9,000 = 3,000. Net migration = 5,000 − 8,000 = −3,000. Total change = 3,000 + (−3,000) = 0. The population stays the same.
2. A village has 800 people. Drought makes 15% of them move to a city. How many move and how many stay?
15% of 800 = 120 move. 800 − 120 = 680 stay.
3. A pyramid has a very narrow bottom and a wide top. What does it say about the population, and which resource problem may follow?
It is an ageing population with few children. Fewer workers will support many older people, so the country may need more workers, such as migrants, and a stronger pension and health system.
Common mistakes
- Thinking resources are equal everywhere. They are spread unevenly, which is why trade and migration happen.
- Mixing push and pull. Push is a reason to leave (drought); pull is a reason to go to a place (jobs).
- Forgetting migration when counting population change. Births and deaths are not the whole story.
- Thinking climate change only affects weather. It also changes farming income, jobs and where people live.