Editorial

Climate change and cities

International negotiations have failed to achieve consensus on climate change mitigation (reducing greenhouse gas emissions). The longer it takes to reach and implement global agreements on reducing emissions, the more adaptation will be needed for expected climate change, and the greater the number of cities (and other areas) for which protection will be impossible or too expensive.

The vulnerability of cities

Urban centres contain a large proportion of the people most at risk from the effects of climate change. Urban dwellers face the threat of damage to their livelihoods, property, quality of environment and future prosperity: they suffer increasing risks from storms, flooding, landslides, drought and overloading of water, drainage and energy supply systems.

Little attention has so far been paid to adaptation in urban areas. Although low- and middle-income nations are often perceived as predominantly rural, they now contain most of the world's urban population and most of its largest cities. Even Africa, long considered a rural continent, has two-fifths of its population in urban areas and a larger urban population than North America.

This issue of id21 insights looks at the risks and challenges faced in cities around the world due to climate change, and highlights practices and policies that could help them to adapt.

Adapting urban centres is important for protecting economies as well as people. Urban centres concentrate enterprises and jobs. In most nations they contain 60-95 percent of economic activities. In this issue of id21 insights, Mozaharul Alam describes Dhaka's vulnerability to climate change. Three other cities that are vulnerable to sea-level rise are described by David Satterthwaite.

The last 50 years has brought a 600 percent increase in urban populations in low- and middle-income nations. The concentration of people and economic activities in low-lying coastal zones has greatly increased, as shown by Gordon McGranahan, Deborah Balk and Bridget Anderson (see graphs below). There has also been a rapid growth in the number of deaths and injuries and scale of economic losses from weather-related disasters – for example, the devastation caused by Hurricane Mitch in many urban (and rural) areas in Central America in 1998 and the devastation brought to Mumbai by flooding in 2005.

The relative contribution of climate change to these disasters is not known. Nevertheless, they do show the vulnerability of urban populations to the kinds of extreme weather events the intensity and scale of which climate change is likely to increase.

The adaptability of cities

Most prosperous and well-governed cities should be able to adapt to likely climate change risks over the next few decades. As the Intergovernmental Panel on Climate Change Fourth Assessment Report notes, urban centres are often capable of considerable adaptation. They have had to adapt in order to function – for instance, creating stable sites for buildings, putting in place infrastructure and ensuring provision for water and drainage. In any well-governed city, many measures are in place to ensure that buildings and infrastructure can withstand extreme weather events.

Urban governments could ensure planned adaptation, with developments in each urban area reducing risks for inhabitants, enterprises and infrastructure. The required tools and methods are well-known and their effectiveness demonstrated in many locations. Durban's adaptation programme is described by Debra Roberts, outlining how adaptation can be integrated into urban development. Hannah Reid describes the emerging international regime to support adaptation.

For large, well-established cities, there are problems with adjusting existing buildings, infrastructure and land-use patterns to the new or heightened risks that climate change brings. But these can generally be addressed by long-term policies which spread the adaptation costs over long periods and by making use of potential synergies between reducing climate change risks and other environmental risks. Most of the risks from climate change comprise heightened levels of risks that are already present.

It would be a mistake to assume that the above – a logical, justifiable, fundable process driven by good science – is easily implemented. National governments can sign declarations at international conferences that recommend the needed measures but then ignore them. In addition, you cannot adapt infrastructure that is not there.

Hundreds of millions of urban dwellers have no all-weather roads, no piped water, no drains and no electricity supplies. They live in poor-quality homes on illegally occupied or subdivided land that inhibits investment in improved buildings. Many tenants have limited ability to pay rent and landlords have no incentive to invest in better quality buildings. Large sections of low-income urban populations live on floodplains or slopes prone to landslides, because these are often the only sites they can occupy within reach of income-earning opportunities.

Who is most at risk?

Much of the risk is concentrated among low-income households, as described by Aromar Revi for India and Patricia Romero-Lankao for Latin America. The cities most at risk are:

• least able to avoid the direct or indirect impacts because of their location – on the coast, by rivers, or where cyclones or hurricanes are common
• likely to be most affected by the impacts because of their physical form – poor quality buildings and lack of water supply and storm drainage infrastructure, for example
• least able to cope with the impacts due to a lack of local government capacity and funding to rebuild or repair damage, restore services and support households to rebuild homes and livelihoods.

The urban populations most at risk are:

• least able to avoid the direct or indirect impacts, because, for example, they live in poor quality homes and in areas with inadequate drainage systems, and are unable to move or change jobs if climate change threatens their livelihoods
• most vulnerable to the impacts, such as infants and elderly people who are less able to cope with heat waves or unable to flee quickly when a disaster is imminent
• least able to cope with illness, injury or premature death; or loss of income, livelihood or property.

What underlies this vulnerability?

For hundreds of millions of urban dwellers, most risk from the impacts of climate change is a result of development failures. In particular, risk is increased by the lack of capacity of local governments to provide infrastructure, disaster-risk reduction and disaster-preparedness, or their refusal to do so in 'illegal settlements'. This makes many people in poorer cities vulnerable to events to which wealthier, better governed cities can adapt.

The vulnerability of low-income urban dwellers to climate change is often put down to their poverty, but it is far more the result of local government failures or limitations. These, in turn, are linked to the failure of national governments and international agencies to support effective urban policies and local governance. Most international agencies have chosen not to invest in urban areas or to have any urban policies over the last few decades.

Saleemul Huq and David Satterthwaite
International Institute for Environment and Development, 3 Endsleigh Street, London, WC1H ODD, UK
saleemul.huq@iied.org
david@iied.org

See also

Adapting to Climate Change in Urban Areas: The Possibilities and Constraints in Low- and Middle-Income Nations, Human Settlements Discussion Paper, Climate Change and Cities I, IIED, London, by David Satterthwaite, Saleemul Huq, Mark Pelling, Hannah Reid and Patricia Lankao-Romero, October 2007 (PDF)
www.iied.org/pubs/display.php?o=10549IIED

'Chapter 7: Industry, Settlement and Society', by Tom Wilbanks, Patricia Romero Lankao et al, pages 357-390, Climate Change 2007: Impacts, Adaptation and Vulnerability, Cambridge University Press, Cambridge and New York, edited by Martin Parry et al, (forthcoming)

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