Cities: Drivers of risk or resilience?

  • 2015•09•21

    By Matthias Garschagen

    This article is part of UNU’s “17 Days, 17 Goals” series, featuring research and commentary in support of the United Nations Sustainable Development Summit, 25-27 September 2015 in New York City.

    Goal #11: Make cities and human settlements inclusive, safe, resilient and sustainable

    In 1950 two-thirds of the world’s population lived in rural areas, while one-third lived in urban areas. By 2050, that proportion will be reversed. It is forecast that by mid-century, cities will be home to some 6.3 billion people – a staggering 2.4 billion more urban inhabitants than today.

    This urban growth will not be spread evenly throughout the world; most of it will occur in Africa and Asia. Across these continents, urban populations will rise by 860 million and 1.2 billion, respectively, according to UN forecasts.

    Sustainable development goal #11 aspires to “make cities and human settlements inclusive, safe, resilient and sustainable”. One of its targets is to protect those in vulnerable situations (natural hazards and disasters). If this target is to be achieved, decision makers will need to consider the question: Does urbanisation make people more, or less, vulnerable to the impacts of extreme weather?

    When mega-trends collide

    Two ongoing mega-trends — rapid urbanisation and climate change — will shape how city-dwellers around the world experience natural hazards. They place a particular focus on how developing countries and emerging economies, such as those in Africa, Asia and Latin America, will cope, because these regions are not only expected to experience rapid urbanisation, but also are likely bear the brunt of climate change impacts.

    In Asia, for example, more than 18% of the urban population lives in low-lying coastal areas, often less than 10 metres above sea level. Dense, low-lying areas such as Ho Chi Minh City, Mumbai, and Jakarta are vulnerable not only to sea-level rise but also to flooding and cyclones. And in many rapidly growing cities, labor migrants and other low-income groups are particularly vulnerable, as they tend to settle in dangerous and exposed areas, such as on the steep, landslide-prone slopes of Rio de Janeiro or in slums along the flood-prone banks of rivers and canals in Mumbai or Lagos.

    Although urbanisation poses challenges, it also offers opportunities when it comes to disaster risk management. Urbanisation can increase disaster risk but also improve risk reduction.

    To fully grasp how urbanisation affects human vulnerability to natural hazards, we need to take a step back and look at the bigger picture. We need to consider how urbanisation affects such key components of risk as including susceptibility, coping capacity, and adaptive capacity.

    Can urbanisation decrease the impact of natural hazards?

    A city’s marginalised residents typically are most susceptible to natural hazards. For example, many labor migrants in Dhaka or Manila live in improvised housing structures in highly exposed locations, which are more likely to be damaged by flooding and storms, and have restricted access to social goods and services (such as sanitation infrastructure, clean drinking water, and health care facilities).

    Yet urbanization also opens up a number of options to mitigate susceptibility. Cities are central drivers of economic growth, and can enable a rise in income both for the economy as a whole and for individuals. This income can be reinvested into reducing susceptibility, for example by improving housing infrastructure and the availability of sanitation and health care.

    Enhanced coping and adaptive strategies

    The pressure of rapid urbanisation can limit governments’ ability to build and operate essential infrastructure such as healthcare and disaster response. But urbanisation can also strengthen coping capacities. The high density of buildings and other infrastructure in cities means that protective structures such as dykes can be implemented and operated more efficiently. And by concentrating large numbers of people, cities can put them in direct reach of disaster facilities such as ambulances or fire brigades. And by boosting income levels, cities can improve individual as well as general coping capacities.

    Yet key factors that improve adaptive capacity — such as investment, educational standards, and public participation — often are lacking in many cities in developing countries and emerging economies. At the same time, exposed cities such as Jakarta and Lagos have high levels of capital, innovation, and political attention. These metropolises thus have the potential to play a pioneering role in developing and implementing effective adaptation measures.

    Urbanisation offers opportunities

    For goal #11 to succeed, decision-makers in individual countries and cities will need to understand the multi-facetted and often-contradictory relationship between urbanisation and natural hazard risk. In this context, it is crucial to harness the opportunities urbanisation presents.

    Whether this can and will be done ultimately depends on how countries implement risk management policies. For example, cities must ensure that urban sprawl does not expand into high-exposure or highly vulnerable areas.

    The interactions between exposure to natural hazards with susceptibility, and coping and adaptive capacities, also point to an urgent need to interlink disaster relief, disaster risk reduction, and development strategies. If new infrastructure such as a school or hospital is built, for example, it should be climate-proofed and located in a low-exposure area. The reality is that cyclones and other natural hazards cannot be prevented, but vulnerability of people to them can be reduced.