A report published by the UN has predicted that the number of ‘megacities’ in today’s ‘developing world’ will rise to 29 by 2025.

It will increase the total number of megacities around the world by 14, pulling 70% of the world’s population into new and existing urban centres.

“Future cities will need to be planned around energy and resource hubs, not infrastructure like highways. If we are to keep increasing our global population by a billion people every 15 years, cities will need to become fewer but denser – think megacities of populations a minimum 1 million per square kilometre,” said Nigel Grier of the Green Asia Group, who spoke at the International Green Building Conference in Singapore last week.

Regionally, Cairo, Karachi, Mumbai, Lagos, Istanbul, Delhi, Dhaka and Kolkata will all be defined as ‘megacities’.

According to the report, in 1950 only New York and Tokyo were classed as megacities.

While Tokyo is predicted to remain ‘the world’s most populous urban agglomeration’ with more citizens than Canada, due to world first infrastructure developments and culture, New York will slip to sixth position by 2025.