“Bonn Dialogues on Global Environmental Change”

"Cities under Climate Threat”

Read the detailed concept note on the event by clicking on "read more" below. 

The 4th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR4) warned in 2007 clearly and unmistakably about the expected impacts of climate change (IPCC, 2007). Scientific consensus suggests that climate change is a dire reality, causing global warming. Even if humanity achieves an immediate curtailing of all CO2 emissions, people would still have to live with a changing climate and its effects in the coming decades. We are only at the beginning of this development, whose consequences will have an impact in the decades to come.

At this time, extreme weather-related events are responsible for approximately 75% of natural disasters. Over the period 2000-2007, their frequency has increased, on
average, by 8.4 per cent per year, and related annual costs exceeded 80 billion US dollars, making up the largest source of disaster costs. These trends reveal the growing problem of increased vulnerability related to climate risks, particularly for the poorest
countries.

Our understanding of forecasts on climate change points to a further increase of existing risks. Human settlements, and urban areas in particular, are now faces with the
challenges posed by the changes in the type, frequency and intensity of extreme events; even areas that have up to date not been affected by extreme phenomena, now have to seriously consider the projected increases in the level of risk.

Developing countries are particularly hard hit by these events, because they have limited capacities for reacting to such events or preparing for them. When they are impacted by extreme events, the effects on existing physical infrastructure, social networks and livelihoods can adversely affect previously sustained development paths and progress. However, industrialised nations will also increasingly have to adjust in order to cope with the effects of the changing climate. The European heat wave in summer of 2003, storms Kyrill in 2007 and Xynthia in 2010 in Germany are characteristic examples of the potential impacts of climate change. They constitute clear warning signals for developed countries.

Importantly, the most disastrous impacts of climate change are felt in circumstances of increased vulnerabilities of human societies throughout the world. This arises, amongst others, through population growth, the increasing dependency on crisis-prone supply lines, uncontrolled urban development in risk areas or the unrestricted overuse of essential resources.

In 2008 more than half the world’s population (approx. 3.3 billion) were living in cities. It is estimated that by 2030 this figure will have grown to 5 billion (UN, 2008). The biggest growth will take place in Africa and Asia (in rates and magnitudes respectively), where the urban population is expected to double between 2000 and 2030. Above all, poorly planned urban development in risk areas combined with factors of social vulnerability (e.g. high population density, lack of basic infrastructure) leads to a rapid increase in disaster risk.

As an illustration, we expect that from 1975 to 2015, that the proportion of large urban agglomerations of over 10 million people that exist in the developing world will more than double - from 40% to 81%. At the same time the number of mega-cities worldwide will grow from a total of 5 to 21. Given recent trends, more and bigger megacities are inevitable in the twenty-first century. Other than their devastating effects for a very large number of densely settled residents, natural disasters in these urban agglomerations have the potential of regional and global “spill-over” effects. This unprecedented growth of the megacity phenomenon increases the vulnerability of urban systems at multiple scales and, in particular, raises significant concerns regarding public health.

While we expect an increasing number of megacities, cities with population of over 10 million people, they are expected to contain approximately the same proportion of the world’s urban population – around 15% (Kahn 2006; UNCHS 2002); the majority of urbanites live in medium-sized or small cities. Furthermore the highest growth rates are observed in medium sized cities developing world cities – subject to much present-day urban pathology.

Additionally, large agglomerations increasingly face a “metropolitan dilemma” of rapid expansion, segregation and socio-spatial polarisation. Given the concentration and density of people, infrastructure systems and accelerating political and social processes, urban agglomerations are particularly vulnerable to all kinds of hazards, which results in losses of life and increases in health problems. In consequence Cities, are therefore the most complex to mitigate and manage when disasters occur. Experience has shown that we cannot hope to minimize the effects of disasters upon cities through the application of engineering approaches alone. As our cities and settlements need to be safeguarded from further devastating losses, it is our ability to make and enhance sustainable choices that needs to be improved upon.

Urbanization is further exacerbated as a consequence of endemic vulnerability to cyclical disasters. Droughts and floods in rural areas for example cause movement of
rural populations into cities and stretch existing urban capacities. The concepts of sustainability and sustainable development offer a valuable framework for integrating
disaster risk reduction (DRR) with other social and environmental goals - before, during and after a disaster. At the same time cities are drivers of development with a huge potential for human society.

The observed increase in weather-related disasters and the expected increase in extreme weather events require adaptations in many areas of society. Such adaptations require not only a solid information base on extreme weather, but also above all structures and strategies for designing long-term planning, which is a very important contribution towards securing livelihoods and the means for providing social and material infrastructure. Several policy instruments have been suggested as urban areas begin to think and act towards adaptation to climate change; these include zoning regulations, building and design codes, terms of financing and early warning systems (Kirshen, Ruth and Anderson 2006). But also possible institutional responses to GEC from municipal and metropolitan governments extended further to comprehensive master plans of urban areas (inclusive of land use and transportation planning), the creation of green infrastructure and wider economic development strategies.

The panel will aim to address the following points:

• What are the major new risks that urban centres will be facing in the future?

• How can existing mega-cities adapt efficiently to the effects of climate change
  and the “new” hazards they may face?
  

• What are the opportunities for rapidly growing cities to plan and adapt to climate
  change?
  

• Can cities be seen as ‘laboratories’ for sustainable adaptation options given past experiences in coping with a variety of challenges simultaneously, e.g. demographically, economically, and challenges with regards to the environment?
  

• Responses to climate change have to occur concurrently at multiple scales, from global to local and across different time scales. Is there key role for urban areas in this respect?
  

• Adaptation options for some societal groups may increase the vulnerability of others. What are the equity dimensions of adaptation in urban areas, which other trade-offs may occur?