Cities 2 Challenges and opportunities

Urbanisation brings both challenges and opportunities for green cities. Challenges include the rapid pace of urbanisation and related pressure on the environment and social relations if it continues on the same trajectory (the business-as-usual or BAU model). Opportunities for green cities include the possibility to design, plan and manage their physical structure in ways that are environmentally advantageous, advance technological innovation as well as profit from synergies that exist between the constituent elements of complex urban systems.

2.1 Challenges

The rapid pace of urbanisation In 2007, for the first time in human history, 50 per cent of the global population lived in urban areas. Only a century ago, this figure stood at 13 per cent but it is now predicted to reach 69 per cent by 2050 (UN Population Division 2006 and 2010). In some regions, cities are expanding rapidly, while in others, rural areas are becoming more urban. A significant part of this urbanisation is taking place in developing countries as a result of natural growth within cities and large numbers of rural-urban migrants in search of jobs and opportunities. Often this happens despite widespread anti-urbanisation policies, which aim to balance development and to sustain rural economies (UNFPA 2007). However, such efforts have mostly been unsuccessful and risk that urban agglomerations are left unprepared for inevitable increase in population growth. Rapid urban growth tends to overwhelm cities where the struggle to develop infrastructure, mobilise and manage resources has negative consequences for the environment.

The scale of the problem comes into sharp focus in India and China. India’s urban population grew from 290 million in 2001 to 340 million in 2008 and it is projected to reach 590 million by 2030 (McKinsey Global Institute 2010). The country will have to build 700-900 million square metres of residential and commercial space a year to accommodate this growth, requiring an investment of US$ 1.2 trillion to build 350-400 kilometres of subway and up to 25,000 kilometres of new roads per year. Similarly, China’s urban population is expected to increase from 636 million in 2010 to 905 million by 2030 (UN Population Division 2010). It is predicted that by 2050 the country will need to invest 800-900 billion RMB per year to improve its urban infrastructure, about one-tenth of China’s total GDP in 2001 (Chen et al. 2008). The nature

Household sanitation Ambient air Carbon emissions

Wealth

Shifting environmental burdens Local

Immediate Threaten health

Global Delayed Threaten life-support systems

Figu re 1: Urban environmental transition Source: McGranahan et al. (2001)

of this investment will have significant effects on the potential of Indian and Chinese cities to be green.

Urbanisation and the environment Cities of different wealth levels impact the environment differently. Local environmental threats are most severe in poorer cities and relate to issues such as fresh water, sewage, health and the degradation of

the living environment.

As cities become more prosperous, with wider and deeper patterns of consumption and production,

environmental impacts are increasingly felt at the global level (Figure 1: Urban environmental transition).

Urban areas in prosperous economies concentrate wealth creation as well as resource consumption and CO2

their

emissions. Globally, with a population share of just

above 50 per cent but occupying less than 2 per cent of the earth’s surface, urban areas concentrate 80 per cent of economic output, between 60 and 80 per cent of energy consumption, and approximately 75 per cent of CO2

emissions (Kamal-Chaoui and Robert 2009; UN

Population Division 2010). This pattern is not equally distributed across the globe and reflects the concentration of particular activities within individual cities. Buildings, transport, and industry – which are constituent components of cities and urban areas – contribute 25, 22, and 22 per cent, respectively, of global energy-related GHG emissions (Herzog 2009). Between 1950 and 2005, the urban population grew from 29 per cent to 49 per cent of the global population (UN Population Division – World

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Severity