According to the Work Bank Today, some 55% of the world’s population – 4.2 billion inhabitants – live in cities. This trend is expected to continue. By 2050, with the urban population more than doubling its current size, nearly 7 of 10 people in the world will live in cities.

With more than 80% of global GDP generated in cities, urbanization can contribute to sustainable growth if managed well by increasing productivity, allowing innovation and new ideas to emerge.

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However, the speed and scale of urbanization bring challenges, including meeting accelerated demand for affordable housing, well-connected transport systems, and other infrastructure, basic services, as well as jobs, particularly for the nearly 1 billion urban poor who live in informal settlements to be near opportunities. Conflicts are on the rise, resulting in 60% of forcibly displaced people living in urban areas.

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Once a city is built, its physical form and land use patterns can be locked in for generations, leading to unsustainable sprawl. The expansion of urban land consumption outpaces population growth by as much as 50%, which is expected to add 1.2 million km² of new urban built-up area to the world in the three decades. Such sprawl puts pressure on land and natural resources, resulting in undesirable outcomes; cities consume two-thirds of global energy consumption and account for more than 70% of greenhouse gas emissions

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Cities play an increasingly important role in tackling climate change because their exposure to climate and disaster risk increases as they grow. Almost half a billion urban residents live in coastal areas, increasing their vulnerability to storm surges and sea-level rise. In the 136 biggest coastal cities, there are 100 million people – or 20% of their population – and $4.7 trillion in assets exposed to coastal floods. Around 90% of urban expansion in developing countries is near hazard-prone areas and built through informal and unplanned settlements.

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