India, China dominate top cities index

Nairobi is projected to have one of the fastest-growing populations in the world over the next five years. The authorities there are turning to smart technologies to help cope with overcrowding, traffic congestion and inefficiency in transportation around the city, according to Kelly.

"This year's rankings find the fastest urban growth continuing to shift away from the West to the East," Kelly wrote in an article posted over the weekend as part of the upcoming World Economic Forum Annual Meeting in Davos, Switzerland, from Jan 22-25.

Global leaders will discuss globalization 4.0 and the Fourth Industrial Revolution and call for more inclusive and sustainable global growth.

Kelly said strong growth brings great opportunities for economic and social development, but equally creates challenges that emerging markets must address to ensure that short-term growth transitions into long-term momentum.

"Cities that are growing rapidly tend to punch above their weight in attracting companies and people; however, this can often lead to social inequality, congestion and environmental degradation," he said.

Kelly pointed out that technological innovation in the form of greener and smarter buildings plays an important role in answering the environmental challenges brought about by rapid growth.

He cited the example of Xi'an which was struggling with severe air pollution as a common plight for developing cities.