The new urban context

In the context of global environmental, economic and social change, perhaps no phenomenon is more striking than urbanization. Already, more than half of the world’s population lives in urban places. Urban lifestyles and the increasing diversity of urban conditions have created not only new social hierarchies and cultural rules, but also a new set of roles for healthcare systems and changing patterns of access to and demand for health and other resources within and between cities. Urbanization represents both opportunity and risk, and a fresh set of challenges for those concerned with protecting and promoting human health and well-being. Propinquity gives rise to both benefits and disbenefits – economies of agglomeration and scale, but also diseconomies of congestion and institutional overload.

Cities have become central to securing the sustainable futures laid out in the New Urban Agenda, the Sustainable Development Goals and other landmark elements of the 2030 Agenda for Sustainable Development. The three pillars of economic, social, and environmental transitions can be best achieved within cities, which account for 75% of global GDP and 75% of global carbon emissions, and city-level actors play an increasingly important role in global and regional affairs.

Science also has a role to play in catalysing the sustainability transition and can be a powerful partner for political actors and decision-makers. The pathways in which science can influence policy and support change must be strengthened and fostered.

The urbanization megatrend (1.5 million people a week are added to the global urban population, and 90% of that growth takes place in African and Asian countries) will place huge demands on infrastructure, services, job creation, climate, the environment, and well-being. Longstanding knowledge-generating machineries such as the Intergovernmental Panel on Climate Change (IPCC) have taken on the urban challenge. But this global urban transition needs a multiscale and multi-dimensional approach.