Solecki et al. 2012
Solecki, W.,, S. Hammer, and S. Mehrotra, 2012: Urbanization of climate change: Responding to a new global challenge. In The Urban Transformation: Health, Shelter and Climate Change. E. Sclar, N. Volavka-Close, and P. Brown, Eds. Routledge, 197-220.
Cities find themselves on the front lines of climate change. The direct effects of a warming earth will exacerbate many longstanding urban ills, such as rapid population growth, sprawl, poverty and pollution, and, in general, climate change will stress the urban environment along multiple pathways. Its indirect impacts and feedbacks will also be most keenly felt in cities, simply because of their concentrated and integrated economic activities, their highly complex systems of infrastructure and social services, and their multilayered governance. Cities will need to find new ways to protect their citizens and assets, to determine how to set investment priorities for strengthening or replacing infrastructure, and to assess how climate change will affect their plans for long-term growth and development.
Cities must also be recognized as crucial elements in any global responses to climate change. Cities generate as much as 70 percent of global greenhouse-gas (GHG) emissions, and so they are obvious targets for mitigation efforts. But they also demand the special attention of policy-makers because of several factors, overlooked in early climate research, that make cities extremely vulnerable to climate change. First, most people on the planet now live in cities, and urban growth is projected to continue well into the twenty-first century, nearly doubling to some 6.3 billion people by mid-century. Second, cities are hubs of economic activity; they often support a larger metropolitan region or even the national economy. That, of course, also gives cities an advantage as well as a vulnerability — since, as centers of wealth and innovation, they often have the best tools and greatest resources for tackling the challenges of climate change. Third, nearly all cities have grown up (and continue to be built up) along coasts or riverbanks, exposing them to some of the most potentially damaging effects of climate change. For example, increases in sea level and large storm surges will threaten critical infrastructure. More frequent and intense floods and droughts will put even greater demands on water supplies that are often scarce already. Fourth and finally, cities have outsize effects on their own environment: among their other environmental impacts, they create so-called urban heat islands (UHIs) and pollute their own air and water.
A generalized vulnerability and risk-management paradigm is emerging that provides a useful framework to city decision-makers for mitigating and adapting to climate change. City managers are increasingly recognizing that the environmental conditions of the past do not provide a particularly useful forecast of future environmental conditions. Instead, managers are depending increasingly on risk-based protocols for dealing with climate change. Frameworks for assessing climate-change vulnerability and risk are typically developed out of three sets of indicators, on the basis of readily available data:
1 The climate hazards a city faces, such as more frequent and longer duration heat waves, more frequent heavy downpours and more frequent and expanded coastal flooding.
2 Demographic and geographic features related to vulnerability, such as the size and density of a city's population, its topography, the portion of its population living in poverty and the fraction of the national gross domestic product (GDP) that the city generates.
3 Indicators of adaptive capacity — in other words, data relevant to the ability of a city to act: What information about climate change is readily available? How many resources can be allocated for mitigation and adaptation? What institutions, governance bureaus and change agents are present and likely to be effective in helping the city to adapt?