The Intergovernmental Panel on Climate Change (IPCC) in its fourth Assessment Report detailed the interaction between human and environmental systems and their modelled climate predictions until 2100. They define climate change as ‘a change in the state of the climate by changes in the mean and/or the variability of its properties, and that persists for an extended period, typically decades or longer’ (IPCC, Climate change 2007: synthesis report. An Assessment of the Intergovernmental Panel on Climate Change, 2007, p. 30). Driving this process are four main factors that alter the energy balance of the earth: emissions of atmospheric greenhouse gases and aerosols from both human and natural sources, changes in land cover and solar radiation. The IPCC report is structured around a framework that links the anthropogenic drivers, impacts and responses to the climate process. This framework contains three interdependent areas, namely: climate change, its impacts and human vulnerability; and development, mitigation and adaptation. The key aspects of climate change that will affect humans are temperature and precipitation levels and patterns, sea-level rise as a result of water expansion and ice melt, and changes in frequency of extreme events. The multidirectional process of climate change impacts human health, water, food and settlement use, and ecosystem evolution. These, in turn, are linked to the socio-economic-political structure and its approaches for adapting to the changing climate, and mitigating the drivers of further climate change.
This chapter adopts a similar structure to the IPCC in addressing the specific factors that shape the responses of urban authorities to climate change in developing and developed countries. The first part of this chapter assesses the impact of climate change on different urban areas and variations by location. The second part identifies the vulnerability profile across the population by examining the risk of exposure and the ability to cope and recover. The third part addresses the capability of urban authorities to respond to climate change by implementing adaptation and mitigation policies. Finally, the chapter concludes by examining the overarching factors that link vulnerability and the structure of the sociopolitical system to how urban authorities respond to the challenges of climate change.
