The impact of urban development on risk in sub-Saharan Africa's cities with a focus on small and intermediate urban centres

The main urban issue that sub-Saharan Africa is facing is rapid growth in its urban population without the urban governance structures in place that can meet their responsibilities and manage the change. This has created very large deficits in infrastructure and service provision which exposes much of the urban population to high levels of risk. Without competent, effective and accountable urban governments, it is not possible to tap the great potential that cities have for supporting good living conditions and good health. This paper examines both the scale of urban change and the development challenge facing sub-Saharan Africa's urban areas and the possible implications on risk. It describes how a substantial proportion of sub-Saharan Africa's national (and urban) population lives in small and intermediate size urban centres (and thus not in rural areas or large cities) and considers what we know about risk in these urban centres and the implications for development. The paper suggests that within the region's urban population, inadequacies in provision for basic infrastructure and services are usually larger, the smaller the urban centre. Most small urban centres in the region have local governments with very little capacity or funding to fulfil their responsibilities for risk reducing infrastructure and services. Of these, the inadequacies in provision for water and sanitation are the best documented. But in some instances, provision for water and sanitation is so poor in large cities that the proportion of their inhabitants lacking adequate provision is as high as those living in small urban centres

Will Africa have most of the world's largest cities in 2100?

This paper responds to the article by Daniel Hoornweg and Kevin Pope, on predictions for the world’s largest cities in the 21st century, in this issue of Environment and Urbanization. It recognizes the value and importance of this article in highlighting the very large likely scale of urban population growth up to 2100 and in initiating a discussion on what this might imply for the scale and distribution of the world’s largest cities. But it raises some concerns about the extent to which very large cities will grow in what are currently nations with very low per capita incomes. Mega-cities need to be underpinned by mega-economies. The world’s largest cities up to 2100 will mostly be those where private capital has chosen to invest, and much of this may not be in the cities identified in the Hoornweg and Pope article as likely to be the largest. The economic future, the development future (including whether the Sustainable Development Goals get met) and the ecological future (especially whether dangerous climate change is avoided) will so powerfully influence future city sizes

Editorial: The full spectrum of risk in urban centres: changing perceptions, changing priorities

In many urban centres in the global South, there is little or no information on either the scale or the causes of premature death, serious injury, illness or impoverishment. In sub-Saharan Africa, this is the case for most urban centres. Even where there may be some information, it is seldom available for every district in the city. We get some sense of the scale of these issues from household surveys (such as the Demographic and Health Surveys), which show very high infant, child and maternal mortality rates “for urban areas” in many African and Asian nations.(1) But for practical action this kind of information is needed for every ward or district – on what the problems are, where they are and who is most impacted. Civil servants, politicians and civil society groups working at neighbourhood, ward, district and city levels may have some sense, based on their experience, of what the concerns are within their jurisdictions. But without data to present to higher-ups, it can be difficult to get proper action in response. The availability of data is worst of all for informal settlements – despite the fact that they often house more than half of a city’s population. In Nairobi, the African Population and Health Research Center (APHRC) has shown that aggregate figures for infant and under-5 mortality rates for the city hide the much higher rates in informal settlements.(2) But this kind of information is needed everywhere, and there is in general scant documentation of the serious risks faced by the billion or so urban dwellers who live in informal settlements

Beyond Stereotypes of Adolescent Risk Taking: Placing the Adolescent Brain in Developmental Context

Recent neuroscience models of adolescent brain development attribute the morbidity and mortality of this period to structural and functional imbalances between more fully developed limbic regions that subserve reward and emotion as opposed to those that enable cognitive control. We challenge this interpretation of adolescent development by distinguishing risk-taking that peaks during adolescence (sensation seeking and impulsive action) from risk taking that declines monotonically from childhood to adulthood (impulsive choice and other decisions under known risk). Sensation seeking is primarily motivated by exploration of the environment under ambiguous risk contexts, while impulsive action, which is likely to be maladaptive, is more characteristic of a subset of youth with weak control over limbic motivation. Risk taking that declines monotonically from childhood to adulthood occurs primarily under conditions of known risks and reflects increases in executive function as well as aversion to risk based on increases in gist-based reasoning. We propose an alternative Lifespan Wisdom Model that highlights the importance of experience gained through exploration during adolescence. We propose, therefore, that brain models that recognize the adaptive roles that cognition and experience play during adolescence provide a more complete and helpful picture of this period of development