Cities are becoming exponentially bigger by the day. As a result, the development problems and the danger of large-scale human tragedies are growing with them. The aftermath of devastations like Superstorm Sandy and the terrible 2010 earthquake in Haiti are examples of the tragic humanitarian consequences that can occur from the failures of urban systems in densely populated areas.
Port-au-Prince in particular, with a moderate population of 2.4 million, is a stark reminder of what can happen when things go wrong in areas of vast concentrations of poor and vulnerable people. We like to believe that these are isolated incidents. But the fact is that humanitarian crises occur with increased frequency.
Many people look to the influence of climate change. But we should pay more attention to the phenomenon of rapid urban growth.
Within the lifetime of most baby boomers, the world's population has nearly tripled, and our planet has been transformed. It has done so not only because there are 4.5 billion more people, but because now more than half of the people in the world — 3.3 billion — live in urban areas.
More alarming is the vulnerability of much of that population and the cities that house them. The fastest-growing segment within the accelerating urban sector is the urban poor. Currently, one third of the world's urban population — one billion people — live in conditions comparable to slums.
To visualize what this means, imagine 120 New York Cities in which every single person lives in a slum. And that number is rising.
Today, a sobering 75 percent of the world's population growth is taking place in the urban centers of the developing world. By 2050, the number of people living in slumlike conditions would be equivalent to the entire global population of 1950.
And the rise of urban poverty threatens to undo much of the economic growth that is occurring throughout the development world.
The pace and the scale of urban growth jeopardize infrastructure, services and systems which are unable to keep pace. Large cities like Dhaka, Nairobi, Rio de Janeiro, Cairo, Lagos and Mumbai, and smaller ones like Port-au-Prince have been vastly outpaced by the population growth. Facilities, services and infrastructure are in short supply.
Meanwhile, tens of millions live in squalid, inhumane conditions in shanty towns at the periphery of cities or deteriorated and dense innercity slums without sanitary facilities, clean water, garbage collection, or proper drainage. Their shelter is often flimsy, usually over-crowded and insecure.
Frequently, they also lack access to education and health. Their employment opportunities are usually within the informal sector and they live with great economic uncertainty. What future can they hope for?
Because this is a global issue, assisting the millions of people who are living in poverty around the world must be the shared responsibility of developed and developing countries alike.
A global effort is required to empower disadvantaged people and communities throughout the world to achieve sustainable economic and social progress, strengthen their communities and civil society, promote democracy and governance, and prepare for and respond to natural disasters and humanitarian crises; thereby advancing the principles by which we can all succeed.
An agenda to build better cities and foster resilience should be prioritized by development agencies and national policy makers alike. No longer can we turn away, for the challenges of people living in urban areas affect us all.