contributing to the economic and demographic growth of a city. Since cities are dependent on biodiversity, for a variety of ecosystem services such as water provision, strategic planning for sustainability is vital to protect existing ecosystems or “ecozones” within or surrounding cities (such as wetlands, rivers and coastal areas), which an increasing city footprint might jeopardize. Global environmental change will affect rainfall patterns. What is relatively certain is that rainfall is already less predictable, leading to uncertainty in timing for crop planting as well as crop failures and insecurity of water supplies. Changing seasonality, that is the earlier onset of summer and altered rainfall patterns, may indeed have the same effect as droughts. Water supply to urban areas will be severely tested in the future, since this is largely linked to rainfall, basic infrastructures and the capacity to use water resources sustainably. In cities where water volume is not climatically or seasonally limited – along large rivers, for example – the primary concerns might be water quality rather than quantity. Rising sea level is not only likely to cause flooding; fresh groundwater may become saline as rising sea levels penetrate low-lying aquifers as experienced in Beira, Mozambique.77
CHAPTER ONE
Energy Supply Throughout Africa, poverty is caused or exacerbated by lack of access and/or inequitable access to energy resources, with scant household resources (including time) being spent on energy provision.78 More than half of informal settlements in Africa rely on bottled gas, paraffin, diesel, coal and wood fuel. In some countries, biomass accounts for 80 per cent of energy use.79 Some countries are providing incentives for reduced energy consumption (distribution of low energy light-bulbs; promoting low current appliances or subsidized domestic solar water heating). For example, the Kuyasa Project in the city of Cape Town, South Africa, is a project harnessing Clean Development Mechanism (CDM) support (see also Box 1.7).
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Waste Management Although African cities generate only between 0.3 kg and 0.8 kg of solid waste per capita/day compared to the global average of 1.39 kg/capita/day,80 poor solid-waste management poses extreme hazards to health and water quality through pollution. In many African cities, waste management systems appear to be absent, with solid waste disposed of directly adjacent to informal settlements in mounds, trenches and near watercourses. There is a relatively large proportion of organics in waste generated in African cities, typically well over 50 per cent.81 The potential for “green economy” projects in waste separation and management is thus high and might reduce the waste disposed through reuse of organics for animal feed, such as in Kampala, Uganda, or the generation of biogas from waste. The capability for trading in the carbon market through the CDM, demonstrated for Matadi in the Democratic Republic of Congo,82 can significantly offset the costs of collection and safe waste disposal. eThekwini Municipality (Durban)
in South Africa has already implemented a waste-to-energy project at its Mariannhill Landfill. Almost invariably, informal settlements and communities of waste pickers arise near formal solid waste landfills. Waste recycling can be lucrative where waste emanates from middle to upper income settlements. But waste-pickers live dangerously, with a high incidence of injuries and infection from sharp objects, medical waste and other hazardous substances in uncontrolled disposal sites. “External” Threats and Shocks There have been predictions of 200 million climate refugees (eco-migrants), with global environmental change viewed as a major driver of renewed rural-urban migrations.83 However, natural growth of urban populations appears to be a far more significant driver of change and vulnerability in Africa than migration, including climate change induced migration.84 Understanding the nature of urban demographics is essential to predicting trends and addressing urban environmental challenges and risks. Health and Sanitation Although recent trends indicate progress and even acceleration towards a healthier Africa, of concern are apparent inequities in the access to basic services which are skewed towards high-income groups and urban areas. Although 42 per cent of the urban population of SubSaharan Africa has access to improved sanitation, low access levels in urban informal settlements can lead to higher risks of diseases. Lack of drainage and piped sewage do increase urban habitats for the anopheles mosquito, thereby increasing vector risk and spread of malaria even during dry seasons.85 Rising temperatures and flooding through global climate change will increase, or certainly shift, the range and spread of the malaria-carrying mosquito potentially threatening previously unaffected highland cities such as Nairobi and Harare.86 Human health contributes to the indices used to determine least developed countries. Existing health and sanitation challenges (particularly those in urban areas) might be further exacerbated by climate change and variability.87 South of the Sahara, only Madagascar and Malawi are on track to reach the Millennium Development Goal (MDG) target (see also Box 1.10) to reduce child mortality by two-thirds in 2015.88 The lack of equitable access to resources and services across the board in African countries89 provides an on-going challenge to health provision. This is particularly significant as urban populations increase. Adaptation versus Mitigation African countries are generally low-level contributors to greenhouse gases, with the Republic of South Africa being the only African country among the world’s top 25 emitters of carbon dioxide over the past several decades.90 Cities generate more than 80 per cent of carbon emissions globally.91 Countries are largely governed from their cities, which also