Megacities, which are typically those cities with a population of over ten million, are grappling with distinct challenges and opportunities as their inhabitants grow or, in some cases, begin to decline.
As of 2023, according to a study reported by Geographical, there are 44 megacities in 5 continents, with the numbers expected to rise to a total of 67 by 2050.
Tokyo remains the largest megacity on Earth, but its population, currently at 37.1 million, shrank by 79,000 in 2022, due to Japan’s ageing population and low birth rates.
With a low immigration rate, experts predict Tokyo’s population could halve within the next 90 years, raising concerns about its global influence.
Meanwhile, Delhi, with 32.9 million people, is rapidly growing. The Indian capital rose by 875,000 residents in 2022 alone, driven by high migration rates, and is projected to surpass Tokyo as the world’s most populous city by 2030.
Shanghai, the largest city in China with 29.2 million inhabitants, continues to expand, though the government has taken steps to cap its population at 25 million by 2035 to tackle issues like pollution and traffic congestion.
Dhaka, the capital of Bangladesh, is the fourth-largest megacity with 23.2 million residents. Rapid urbanization has contributed to its population growth, but the city faces severe challenges with poverty, overcrowding and infrastructure.
Coming in fifth is São Paulo, Brazil’s largest city, home to 22.6 million people, with population numbers expected to hit 23 million by 2030. The city continues to face urban development concerns, especially in terms of a reliable and efficient public transport system.
Policy trends in megacities illustrate a broader global phenomenon, where population pressures actively shape urban planning, infrastructure needs, and economic futures.