World population and megacities

In short: The world population passed eight billion in 2022. More than half live in cities. Megacities have more than ten million inhabitants.

In more detail: Growth is slowing because birth rates are falling in many countries. Projections see a peak in the second half of the century.

In detail

• Most populous countries: India and China with about 1.4 billion each.
• Megacities: Tokyo, Delhi, Shanghai, São Paulo, Cairo are among the largest.
• Urbanisation: People move to cities for work, education and healthcare (industrielle-revolution).
• Challenges: Housing, traffic, air quality, water, waste, slums.
• Demographic change: In many industrialised countries society is ageing; in Africa it is very young.
• Sustainability: Resource use per head is far higher in rich countries (klimawandel-grundlagen).