Even as megacities are created by confluence of government, industry and finance, the concentration of critical infrastructure and mass transit systems also make them vulnerable to terror, US ambassador to India Richard Verma said here on Monday.
A look at the world's top 30 megacities reveals a common characteristic, regardless of geography or levels of economic development, that they have suffered terrorist attacks.
"The people of Tokyo, Jakarta, Manila, Karachi, New York, Mumbai, Bangkok, Dhaka, Istanbul, Lagos, Paris, and London have all seen first-hand the horrors terrorists can inflict," Verma said.
In this context, he referred to social media platforms which are enabling radicalisation, recruitment, and networking among like-minded individuals from afar.
He was speaking at an international conference on 'Megacity Security: Challenges & Opportunities'.
Small groups and individuals have access to lethal and even military-grade technologies that give them the ability to attack a city's functioning, besides communications and transportation networks, essential to the daily needs of cities and which also serve "as enablers that allow groups to recruit and maintain networks with relative anonymity".
"Even Smart Cities, which offer the promise of a greener and more sustainable future, can be vulnerable to cyber attacks," Verma cautioned.
Another potential security challenge emanates from the inability of megacities to uphold their end of the social contract through effective governance and service provision.
Megacities are home to youth unemployment, internally displaced, international migrants, ethnic and religious tensions, immense health and environmental challenges, resources becoming limited, populations concentrated in substandard housing and vast public corruption, Verma added.
"Marginalised urban populations facing grinding poverty and squalor can also become vulnerable to criminal gangs, organised crime, and even terrorist recruitment. Poor governance can allow these groups to form and even thrive," he warned.
He pointed out that in 1950, there were only two megacities, New York and Tokyo, with Mexico City joining the list only in 1975.
Today, there are approximately 30 megacities - cities with more than 10 million people, including three in India - Mumbai, New Delhi and Kolkata.
It is estimated that by 2030, another dozen cities will be added to the list of megacities in the world as we are witnessing an unprecedented shift in population from rural to urban centres, approximately 200,000 people per day around the world.
A century back, just two out of 10 people lived in cities, while today more than half the world's population is in cities. In the early 1800s, London and Beijing were the only cities with a population of one million-plus, now it has grown to 450.
According to the Economist Intelligence Unit, by 2050, 70 percent of the global population will live in cities, with most growth taking place in existing cities.
For instance, Lagos could double in 30 years, Dhaka attracts 400,000 rural migrants each year and the greatest urbanization will be seen in Africa and Asia, with the fastest growing megacities in the past decade being Karachi, Lagos, Dhaka, Delhi and Jakarta.
The UN has predicted that the global population would increase by 2.5 billion over the next 35 years, with 90 percent growth concentrated in Africa and Asia.
In India, the UN has estimated a growth in urban population by nearly 250 million in the next 20 years, and her population will experience more rapid growth than China, South America or the west.
By 2030, besides the existing three megacities, Chennai, Bengaluru, Hyderabad and Ahmedabad shall join the list with New Delhi slated to become the world's second largest city with a population of 36 million.
