A key element of this will be the ability of cities to provide security for their residents, businesses and visitors. Thus, urban management will play a fundamental role in defining the quality of life of most human beings in the coming years.

On the other hand, if they are effectively addressed, the growth of cities may become an essential part of how emerging economies find a way to catch up to those in more developed countries and how humanity as a whole creates more sustainable ways to live. Indeed, the challenges of urbanisation, if unmet, can entail substantial human and economic risks. This process is occurring most visibly in developing countries, some of which struggle to deal with the extent of change. By 2050 68% will do so, reflecting a speed of urbanisation even faster than previously predicted.

Humanity is a predominantly urban species, with over 56% of us living in cities.

Gino Van Begin, secretary-general, ICLEI.

Adie Tomer, leader, Metropolitan Infrastructure Initiative, Brookings Institution.

Fumihiko Nakamura, vice-president, Yokohama National University.

Esteban Leon, chief of risk reduction unit and head of the city resilience profiling programme, UN-Habitat.

Victor Lam, chief information officer, Government of Hong Kong.

Elizabeth Johnston, executive director, European and French Forums for Urban Security.

Ede Ijjasz-Vasquez, senior director, Social, Urban, Rural and Resilience Global Practice, World Bank.

Lord Bernard Hogan-Howe, former commissioner, London Metropolitan Police.

Emmanuel Grégoire, deputy mayor, City of Paris.

Gregory Falco, cyber research fellow, Stanford University.

Thomas Bollyky, senior fellow, Global Health, US Council on Foreign Relations.

Alioune Badiane, president, The Urban Think Tank Africa (TUTTA), Senegal.

Siddharth Agarwal, director, Urban Health Resource Centre.

Our thanks are due to the following people (listed alphabetically by surname) for their time and insights: Findings from the index were supplemented with wide-ranging research and in-depth interviews with experts in the field.

Global city rankings 2019