The Greatest Migration in Human History
🌆 The Greatest Migration in Human History
Today, more than half of humanity lives in cities. By 2050, it will be 7 in every 10 people. Somewhere right now, in Lagos or Dhaka or Mumbai or Kinshasa, a family is packing their possessions, saying goodbye to the village where their grandparents were born, and boarding a bus to a city where they have never lived. They are joining the greatest voluntary mass migration in human history — and it is happening, every single day, at a pace that the industrial revolution never came close to matching.
Consider this: every single week, 1.4 million people in the developing world move to a city. That is the entire population of Greater Manchester arriving in urban areas — every seven days. The scale is almost impossible to comprehend. And it is reshaping the world — creating extraordinary opportunity, spectacular wealth, cultural energy, and at exactly the same time, some of the most severe poverty, overcrowding, and environmental pressure the planet has ever seen.
This topic is about understanding why that is happening, where it is concentrated, and what it actually looks and feels like on the ground in one of its most dramatic locations: Lagos, Nigeria.
Geography glossary
- What is a megacity?
- A city with a population above 10 million.
- What is urbanisation?
- An increase in the proportion of people living in towns and cities.
Urbanisation is the increase in the proportion of a country's population that lives in towns and cities, rather than rural areas. Notice that it is a proportion, not an absolute number — a country's urban population can grow while its rural population also grows, but if urban areas are growing faster, urbanisation is o
Earn the mark scheme marks
🧠 Remember Lagos With TOSH + OPEN
Two mnemonics to organise your Lagos knowledge for the exam.
TOSH — The Four Challenges of Rapid Urban Growth in Lagos:
- T — Traffic — some of the worst congestion on Earth; 3–5 hours commuting per day; $1bn/year productivity loss
- O — Overcrowding and informal housing — 60–70% in informal settlements; Makoko (100,000 on stilts); 30,000 evicted 2012
- S — Sanitation and water — 40% lack clean water; open drains; cholera outbreaks; lagoon pollution
- H — Hazards (flooding and environment) — Victoria Island floods; sea-level rise; e-waste; coastal erosion
OPEN — The Four Opportunities Urban Growth Creates in Lagos:
- O — One billion dollars — Nollywood generates $1bn/year; world's second-largest film industry
- P — Port and finance — Africa's largest stock exchange; leading financial centre; major port
- E — Education and services — Lagos University; teaching hospitals; far better access than rural Nigeria
- N — New tech (Yabacon Valley) — Flutterwave, Paystack; fintech revolution; 200,000 BRT passengers/day
In the exam, TOSH gives you your challenges; OPEN gives you your opportunities. A balanced 8-mark answer uses both.
Push and Pull — remember the key distinction: Push factors are about what you're escaping from (drought, job losses, conflict). Pull factors are about what you're drawn towards (wages, services, networks). Push comes first in time — something has to make you leave before you decide where to go.
Now try it yourself
Quiz · Question 1 of 17
What is the definition of urbanisation?
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This topic in real past papers
Every real exam question we've found on urban growth and the global urban world, with a full worked answer.