One of the most significant issues posed by rapidly expanding urban cities is their sustainability. Urban cities occupy only one half of a percent of the world’s total land area, yet the consume three fourths of its natural resources. If this level of demand continues to rise as the world urbanizes further, cities will quickly become unsustainable.  A second major issue for rapidly growing cities is the development and improvement of infrastructure to support the influx of people. Experts a PwC estimate that over the next ten years approximately $8 trillion must be invested in infrastructure to support growing populations in New York, Beijing, Shanghai, and London alone. This does not account for the world’s nearly 20 other megacities, with populations exceeding 10 million people.

Although rapid urbanization brings many daunting challenges, there are also many opportunities. One opportunity some city planners are hoping to capitalize on is the development of smart cities. These so-called smart cities are manufactured cities, designed with the intent of being self-sustainable. In the next two years, experts believe spending on smart cities will reach $1 trillion, the most notable of which being Madsar City in Abu Dhabi and Migaa in Nairobi. If these ventures are ultimately successful, they could be the benchmark for the cities of the future.

In summary, the world’s population is increasingly flocking to urban areas and bringing a tremendous set of new problems with them. If these problems go unmitigated, they could have a crippling effect on our cities economies, and as an extension, the global economy, considering that half of the global economy's GDP is generated from our 300 largest cities.