In developing countries on average across the world, the proportion of the total population living in cities is about 45 percent, but it has been increasing rapidly and pretty soon, it'll be about 50 percent. In Africa, there's a bit more of a lag in the system. Currently in 2016, about 38 percent of total population Africa was living in cities and urban areas, about 380 million people, but the projections are for this trend to continue, this trend of urbanization to continue across Africa as in other developing countries. So by the 2050, about 33 years time as we speak now, over 56 percent of population Africa will be located in urban areas. This proportional change is happening at the same time as Africa's population is growing at a much more rapid rate relative to other regions of the world. So, as we've talked about earlier in the course, the population of Africa is expected to double from one billion to two billion by the middle of the century, and 70 percent of this extra one billion will be sitting in urban areas. So, by the 2050s, we expect approximately 1.2 to 1.3 billion people to be living in cities and towns in Africa. So what this means is that both, globally, as cities get bigger and more and more of the population is concentrated in cities and especially in Africa where this rapid urban growth is going to be happening, cities become increasingly locations where climate risk is concentrated. That's because of the number of people but also because of the physical assets that occur in cities. So as cities have a very large built infrastructure, whether it's office blocks, transport, electricity, homes etc, and they're also the locus for much of the economic activity that happens in a country. So across the world, 80 percent of economic activity occurs in cities. It's lower in Africa at the moment because that transition is still happening, but over time, Africa should probably reach that kind of level of where cities dominate the national economy. Cities are also important because climate impacts on cities have impacts on wider national economies and structures. So a damage to a city can have a number of implications for critical services for the rest of the country. One of them is around government. So, most governments, whether it's a national government or a regional or provincial government, are located in cities. So, if there's a natural disaster that affects government then that ripples out into the way that the rest of the country is governed. Many critical economic centers are situated in cities. So that can be financial centers such as banks, stock exchanges etc, as well as telecommunications and the Internet. They're all located in cities. So, if your telecommunications hub goes down, then you lose communication across the whole country, not just in the city. The Sanford transport hubs or ports and rail junctions and distribution centers, this is where goods and materials come into the country and then distributed across the country. So disruptions mean disruptions that are countrywide. So, the cities have this dual criticality in the national context. They're very important on their own, but they also can produce these ripple effects through the wider economy and across the country. So that's kind of all the risks that cities pose, but they also present opportunities for what some people call concentrated adaptation. So, because so many assets, so many people, so much of the economy is located in the cities, investing in building resilience and enhancing adaptation in these areas really has disproportion impacts across the economy and the number of people who are affected. So there really are becoming a hotspot and a focus for adaptation and broader sustainability thinking globally, and cities have their own sustainable development goal SDG number 11, which talks to sustainable cities and communities. At the same time, the climate change adaptation is becoming a focus globally and in many cities and their alliances of cities that are getting together to cross-learn and share experiences about how to build climate resilience as part of their broader sustainability agenda. But cities are also very challenging, adaptations tricky. They bring together many discrete risks if you like through food, water, infrastructure, transport, services, health, businesses and manufacturing. So, this complex set of parallel and interacting risks or sectors that occur in cities mean that you need complex management and governance structures to cope with the risks that are presented, and that's partly because of this multi-sectoral nature of a city but also the multi-level nature of a city going from households up into communities into suburbs and then into the whole city itself. So, the context within which adaptation has to happen is tricky, and as we'll see in other parts of the course this week, African cities add particular extra challenges to this already tricky task of adapting statistic climate change. First as this rapid growth in cities that we're going to be seeing in Africa. As cities are growing fast, the existing resources of a city tend to be stretched, and so then started to think about how to manage climate change just adds an additional stress in already stressed management system. The other really complicating factor with regards to African cities is this expansion is largely happening through the growth of informal settlements or slums. So, currently, about 56 percent of people in African cities live in slums, and if we take that through to 2050 and assume that the same dynamic is happening, you're going to have half a billion people or more than half a billion people living in informal settlements in cities, and within these informal settlements that some of the heightened vulnerability occurs. These settlements are kind of disconnected from the formal services and structures through which adaptation and resilience building might occur and therefore that makes adaptation in these particular locations much more difficult than in more formal parts of the city.
