This report explores for the first time the scale of the challenge for 20 cities across the world to reach selected targets set out in the Sustainable Development Goals (SDGs). More than half of the targets included will require a profound acceleration of efforts if they are to be achieved by the majority of selected cities.

With the Sustainable Development Goals (SDGs) now agreed, the real test of their success lies in their implementation. Over half the world's population now live in cities and by 2050 this will rise to two-thirds. Most of this growth will take place in developing countries due to rising migration from rural areas.

Data collection methods and poverty measures have not caught up with the reality of an increasingly urbanised world; as a result, it is increasingly likely that urban poverty is underestimated.

The Sustainable Development Goals (SDGs) will set the global development agenda for the next 15 years, with SDG targets acting as a benchmark of progress for rich and poor countries alike.