VULNERABILITY TO TEMPERATURE-RELATED HAZARDS: A Meta-Analysis and Meta-Knowledge Approach
P. Romero-Lankao et al., Global Environmental Change (2012), http://dx.doi.org/10.1016/j.gloenvcha.2012.04.002
This article conducts a meta-analysis of 54 papers looking at urban vulnerability to temperature-related hazards, covering 222 urban areas all over the world. The authors find that the vast majority of papers are focusing on establishing the epidemiological linkages between temperature and mortality, with very few attempting to understand the inherent structural drivers and mechanisms determining differences in vulnerability to temperature-related hazards within and across communities and cities.
Such a tendency, according to the authors, is due to the difference in adopted conceptual frameworks. The authors assert that the predominant conceptual framework adopted in current literature is considering vulnerability as impact, which conceives vulnerability as an outcome determined by exposure to hazard such as rising temperature, sensitivity of urban populations, and the resulting or potential impacts. In contrast, conceptual frameworks—examining inherent urban vulnerability, which considers the adaptive capacity and structural drivers that determine the varied vulnerability among urban population, or examining urban resilience, which considers that cities can be negatively affected but have the ability to bounce back, recover, or even take advantage of hazards—are not widely adopted in urban temperature-related vulnerability studies. This is somewhat surprising, as conceptualizing vulnerability as exposure, sensitivity, and adaptive capacity combined is becoming common in vulnerability literature. On second thought, this probably is due to the fact that many literature reviews do not consider urban vulnerability per se, but rather focus on finding the epidemiological linkage, for example, between temperature and mortality. In this sense, a different set of literature, or a different choice of hazard other than temperature, might present a very different finding in terms of predominant conceptual framework in vulnerability studies.
Another interesting finding of the paper is that most studies are focused on a single event of short-term impact. The significance of the temporal dimension in vulnerability assessment is an important but much-neglected aspect. A recent study looking at vulnerability of a rural community to landscape urbanization finds that vulnerability of a local community tends to increase with initial exposure to the impact, but can peak and start to improve with increasing integration of the local community into the industrial and urban development and associated increase in adaptive capacity.1
One of the key questions the authors attempt to answer in this paper is whether it is possible to go beyond varied case studies and different approaches, to develop an integrated understanding of urban vulnerability by identifying repeated patterns and relationships. This is an important question to ask, and resonates with similar questions raised by others. In a study looking at 30 different urban sustainability practices in Asia, Bai et al.2 identified that a key challenge in urban research is that most approaches are case-analysis-based, and while the diversity and context-specific findings add richness to the knowledge, the lack of a systematic analysis across different cases to extract common patterns is hampering knowledge transfer and cross-city learning. While the Bai et al. work developed an original framework and associated methodology and examined each of the cases according to that framework and method, the article by Romero-Lankao et al. takes the findings of each study, conducted by a different approach and indeed different purpose, at its face value, which somehow limits the capacity to truly identify common patterns and relationships. Therefore, rather than truly tackling the question of commonality across cases, the Romero-Lankao et al. research is more about categorizing existing findings. However, this probably is an inherent limitation of any literature-based meta-analysis.
As noted by the authors, many of the urban temperature-related vulnerability studies are focusing on epidemiological linkage between temperature change and mortality, without looking too much into the determinants of such linkages. This limitation, with the importance of inherent urban structure, be it physical or social, in determining health outcome, is increasingly recognized within the health community as well. The International Council for Science's new program on Health and Wellbeing in a Changing Urban Environment advocates a systems approach towards urban environment and health and wellbeing outcome.3 Under such an initiative, more research will hopefully tackle the underlying causes linking urban environment to human health and well-being, which will bring new perspectives and findings on temperature- or other factors related to urban vulnerability.
1. Y. Huang, F. Li, X. M. Bai, and S. Cui, “Comparing Vulnerability of Coastal Communities to Land Use Change: Analytical Framework and a Case Study in China,” Environmental Science & Policy 23, 133-143.
2. X. M. Bai, B. H. Roberts, and J. Chen, “Urban Sustainability Experiment in Asia: Patterns and Pathways,” Environmental Science and Policy 13 (2010): 312–325. doi:10.1016/j.envsci.2010.03.011
3. International Council for Science, “Report of the ICSU Planning Group on Health and Wellbeing in the Changing Urban Environment: A Systems Analysis Approach” (International Council for Science, 2011). Paris.