Climate change and disaster risk in urban environments
by Elike van Sluis and Maarten van Aalst, Red Cross/Red Crescent Centre on Climate Change and Disaster Preparedness November 2006

Climate change is projected to increase the likelihood and severity of a wide range of extreme weather events, many of which particularly affect urban area. Given urban areas’ high population densities, often including high concentrations of vulnerable people, increasing urban disaster risk should be a key concern in discussions of the adverse impacts of climate change. 

This article presents two specific examples of increasing risks due to climate change in urban environments, and illustrates how Red Cross/Red Crescent societies address these concerns. The first case is the increasing risk of heat waves, illustrated by the 2003 heat wave in Western Europe. The second is increasing rainfall variability and sea level rises in Jakarta, Indonesia. Both cases highlight two key messages. The first is that climate change is a serious concern, and is relevant to urban disaster managers. The second is that climate change does not require a completely different approach to disaster risk management; instead, the solutions are part and parcel of regular disaster reduction.


Lessons from the 2003 heat wave in Europe: caring for the most vulnerable groups

The European summer of 2003 was probably the hottest for 500 years. Due to climate change, we can expect more of the same: in a groundbreaking article in the prominent scientific journal Nature, Peter Stott and colleagues showed that the probability of such a heat wave has doubled due to greenhouse gas emissions. Furthermore, the authors project that this risk will increase 100-fold over the coming four decades. By the end of the century, the summer of 2003 will probably be considered a relatively cold one. In 2003, however, European societies were clearly very poorly prepared for such conditions. The heat wave resulted in unusually large numbers of heat-related deaths. The scorching heat and drought also caused significant economic losses, estimated in excess of $13 billion.

The key lesson of the 2003 heat wave was that heat risks particularly affect the most vulnerable groups of society, especially isolated poor and elderly people in urban areas. Research in the United States shows that 60–70% of the additional deaths during or shortly after heat waves is strongly attributable to the heat (these people would not have died in the first four months following the heat wave). The effects of the heat wave were particularly severe in France. The high temperatures occurred during the holiday period (quite a likely coincidence), and so government services in large urban centres like Paris and Lyon were considerably reduced, and the social network of families looking after their elderly parents had been weakened. During the first week of the heat wave, the authorities failed to pick up the early signals; emergency services and funeral parlours were among the first to experience the impact of the disaster. In the second week, the media began reporting on the crisis, but even then the government failed to mobilise an effective response.

When the scale of the disaster became clear, it led to significant public outcry and debate about the way France handles its elderly care. The government responded by developing a heat wave plan of action (the Plan Canicule), which includes local government, the health sector and other relevant partners, including humanitarian organisations like the French Red Cross. The French Red Cross has initiated heat wave-related activities at various levels: 

1) Support to the most vulnerable people:

  • Encouraging isolated elderly and/or handicapped people to become involved in their communities.
  • Providing information for and paying attention to these people.
  • Creating a (cool) shelter where vulnerable people can stay during heat waves.
  • Organising home visits to isolated elderly people.

2) Support to the general public:

  • Supporting telephone circles to check on vulnerable people.
  • Supporting hospitals’ response services.
  • Supporting fire departments.
  • Distributing drinking water to drivers caught in traffic jams, or in densely populated areas.

3) Support to health centres:

  • If needed, the French Red Cross will support old people’s homes, home service centres and shelters.

Similar plans are in train in other European countries, including more northerly states such as the Netherlands (which registered 1,500 additional deaths during the 2003 heat wave). The Netherlands Red Cross has initiated pilot activities to investigate how to mobilise its volunteers (many of whom would be on holiday) during heat waves and to enhance its outreach to vulnerable groups in society. At the same time, it is scaling up its advocacy efforts with government institutions.


Climate risk management in Jakarta

Heat waves such as the one in 2003 demonstrate that climate change is a real issue for urban disaster risk management right now. However, climate change will have many impacts well beyond just higher temperatures, and also well beyond Western Europe. In fact, developing countries are projected to be most severely affected, largely because they are already more vulnerable to current extremes, and are less able to adapt to future changes.

Relatively simple interventions can often go a long way towards reducing climate risk in such situations. In Indonesia, the Indonesian Red Cross (Palang Merah Indonesia (PMI)) has invested increasingly in disaster risk reduction, in particular through integrated community-based risk reduction, which aims to strengthen the capacities of vulnerable communities. PMI has initiated a pilot project in two poor districts of Jakarta Province to explore how to integrate changing patterns of risk due to climate change – including increasingly erratic rainfall and sea level rises – into its regular operations, and how to engage in new partnerships to enhance its knowledge base and advocacy impact. PMI is also experimenting with microfinance solutions for disaster risk reduction.

A rise in the sea level is of particular concern in Jakarta because parts of the city are already subsiding due to over-exploitation of ground water and soil compression by heavy construction. The areas most vulnerable to inundations caused by tidal waves and riverine flooding are inhabited by Jakarta’s poorest people. In addition, climate change will affect the occurrence of vector-borne diseases such as malaria and dengue fever, as well as diarrhea (through increases in droughts and floods). All three of these diseases are already serious health problems.

In May 2006, PMI conducted a participatory hazards, vulnerability and capacity assessment (HVCA) in the two pilot districts, in order to identify the strengths and weaknesses of households, communities and institutions; to raise public awareness of hazards, vulnerabilities and capacities; and to support communities in prioritising risk reduction activities. Instead of focusing specifically on climate change, the assessments discussed a broad range of concerns facing these communities, including natural hazards. The implications of climate change were investigated by discussing the history of disasters and diseases, the relationships between disasters, diseases, seasonal change (wet/dry season) and climate change; an analysis of trends and changes; and calendars of community activities, community income and gender-based economic issues. These results were complemented by information collected via secondary data, semi-structured interviews with key informants and transect walk/mapping. Together, this information provided a well-informed analysis of the hazards, vulnerabilities, risks and capacities in the targeted communities.

The assessment resulted in a community-based risk reduction programme. In many ways, the programme looks like any other PMI risk reduction project: its aims include improving access to safe water and health/hygiene facilities, informing people how to maintain a clean environment and raising awareness of risks within the community. Yet while climate change does not result in large changes in the nature of risk reduction activities, it is seen as an incentive to undertake more of these activities. Whereas in the past extreme weather events were considered bad luck or acts of God, today PMI helps people in the Jakarta slums to realise that they may well be facing an increasing risk of, in this case, floods, and that they are able to reduce that risk by better preparedness, for instance through a community-based early warning system, a contingency plan and a contingency fund (financed by the beneficiaries), and improved knowledge of community-based risk mitigation measures. Examples of such community-based mitigation measures to be implemented over the next few years include: the development of a warning dissemination system, including evacuation planning; regular exercises/drills; training individuals in disaster response behaviour; clean water supplies and sanitation; strengthened houses/facilities; and the construction of evacuation centres.



The two examples described here underscore several general messages about climate change and urban disaster risk. Climate change has important implications for urban disasters, and is a serious concern for humanitarian organisations dealing with urban risk. However, climate change does not require a completely different approach to disaster risk management. Instead, enhancing ‘regular’ disaster reduction is one of the best ways to mitigate the increasing risks. With small additional efforts (such as the establishment of networks of partners that can provide climate information or help address the rising risks, and the incorporation of information about changing risks into risk reduction programmes), such efforts can be made even more effective.


Elike van Sluis (, Senior Program and Communications Officer, and Maarten van Aalst (, Lead Climate Specialist, Red Cross/Red Crescent Centre on Climate Change and Disaster Preparedness. For more information on disasters and climate change, and particularly its implications for humanitarian organisations, please contact, or visit