A 4-Step Approach to Building Heat Resilient Cities

The past decade has seen a dramatic rise in the number of already hot days getting hotter, and increased frequency of deadly heat waves, defined as prolonged periods of excessive heat.  

The global upward trend of extreme heat has contributed to the severity of summer wildfires and drought conditions, and the impacts of heat waves are borne disproportionately by the most vulnerable populations. Factoring in a deadly pandemic, traditional coping mechanisms, including moving vulnerable populations to crowded ‘cooling centres’ may increase the transmission rates of the disease.

In a study in Environmental Research Letters, strategies and a framework to reduce urban vulnerability to extreme heat was discussed. The authors, Wilhelmi and Hayden argue that an interdisciplinary approach is required, including information about weather and climate, the natural and built environment, social processes, interactions with stakeholders and assessment of local community vulnerability. 

In considering exposure to extreme heat, the authors identify ‘urban heat islands’ as compared to suburban and rural environments. The temperature gradient may be as high as 10 degrees in denser developments, due to excess heat absorbed and released from denser development. This differential distribution of heat in urban and non-urban neighbourhoods contributes to an increased perception of risk and vulnerability. Vulnerability can be defined not only by the physical proximity to the risk, but by the safety nets that may or may not be available to affected populations. 

The C40 Cities Climate Leadership Group, chaired by Mayor Eric Garcetti of Los Angeles have developed a number of best practises to begin to adapt cities to extreme heat: 

Measure urban heat and vulnerability to understand the risk. Vulnerable population groups, including the elderly, young children and those with underlying conditions are among the most sensitive to extreme heat. Individuals experiencing homelessness and other marginalized groups may not have equitable access to water, green spaces and air conditioning. In addition to identifying these groups, it’s important to identify the local temperature threshold at which heat becomes a threat. 

As an example, in Durban, South Africa, heat vulnerability maps have been created by using information about temperature projections and information regarding urban surfaces (roads and buildings), overlaid with socio-economic data. The result has been a social vulnerability index for sensitivity to heat that can help to guide policy decisions:

Heat vulnerability map of Durban, South Africa

Develop a heatwave response plan. Heat vulnerability maps, once in place can guide policy in advance of heat season. Cities are wise to build collaborative partnerships between governments, meteorological agencies, health and emergency departments, the media and other partners to develop a comprehensive response plan. Building local capacity among health-care professionals and communication with the public may raise greater awareness about the heat risk and ways to negotiate it. 

Cooling centres and cool routes, along with specialized apps to communicate with citizens may help to raise awareness. Cities such as Paris, Athens and Rotterdam have developed the EXTREMA app to assess heat vulnerability and direct vulnerable individuals to local cooling centres. 

Develop long-term plans to reduce the heat threat. Heat mitigation solutions are part of wider urban planning initiatives and may include cool roofs, pavements and road surfaces. Green roofs and walls can also help to reduce temperatures, in addition to increased planting of trees and urban vegetation. Increased vegetation also may help to reduce the risk of flooding. 

The NYC Cool Roofs initiative for example provides local jobseekers with valuable training and work experience, that has since been replicated in Spain and South Korea. 

Raise awareness of actions to reduce urban heat. Developing information materials with broad appeal may help in achieving secondary benefits such as the creation of jobs, reduced energy costs, improved energy security and air quality, and overall well-being of residents. 

Worldwide, heat waves currently impact 200 million people in 350 countries. The Paris Agreement on climate change outlines a target of an overall 1.5 degree reduction, but if this goal is not met, 1.6 billion people may be impacted by urban heat by the 2050s. 

Heat waves are predictable hazards. Mitigation actions by cities and governments may help to address and understand heat risk, particularly for those most at risk.

Understanding and Applying the Sendai Framework to DRR

Our current understanding of disaster and emergency management requires a paradigm shift. For too long, the cycle of disaster -> response -> recovery -> repeat has been the norm. This paradigm shift involves reducing risks themselves, not simply preventing disasters.

In 2000, in recognition of the growing number of people impacted by natural disasters across the globe, the United Nations International Strategy for Disaster Risk Reduction (UNDRR) was formed to support and coordinate organizations in their work building resilient communities. The Sendai Framework for DRR 2015-2030 was endorsed by the UN General Assembly in 2015 and recognizes the central role that the State has in reducing disaster risk, in consultation with local governments, stakeholders and the private sector. 

Image source: http://www.undrr.org

In response to the unprecedented 2017 flood and fire season in British Columbia, an independent review was commissioned on how emergency management agencies may begin to address the “new normal” of increased natural disasters, both in number and severity. A wide cross-section of perspectives were sought, from Indigenous and non-Indigenous communities, organizations and other stakeholders. 

The recommendations contained in the report fall under four broad themes, consistent with the Sendai Framework on DRR:

Partnerships and participation

The response framework in place during the 2017 disaster season resulted in resources, particularly the B.C. Wildfire Service being stretched beyond its limits. In the midst of an emergent situation, citizens (with an intimate knowledge of their lands) will often take it upon themselves to mitigate the spread of wildfires and damage. Enhanced partnerships with these ‘spontaneous volunteers’ is the subject of much discussion in current emergency management literature, and will be covered further in a future post.

Knowledge and tools

Indigenous and local knowledge is not effectively incorporated in current ICS and incident management planning. Further, the frequent reassigning of personnel during the 2017 wildfire resulted in valuable time being wasted as teams were frequently relocated to other provincial regions. Enhanced technology tools, including LiDAR would assist B.C. in developing more comprehensive preparedness and prevention strategies. A keen and comprehensive understanding of DRR would assist in maximizing Indigenous and local knowledge, incident action planning and the incorporation of enhanced technology. 

Communication and awareness

One of the 14 core features of the ICS system is the need for integrated and interoperable communications, processes and structures. Yet, as anyone involved in an EOC will tell you, communications often fail. In the 2017 B.C. wildfires, those people (rightly) seeking information about the condition of their homes and properties faced innumerable challenges and misinformation spread on social media. In my experience (anecdotally), similar challenges were faced by individuals in the 2013 Southern Alberta floods and the 2016 Fort McMurray (RMWB) Wildfire events. Significant investment in information-sharing between response authorities and the public is required in order to bridge the gap and prevent further trauma to impacted individuals. 

Investment

Interestingly, respondents of the report emphasized the disproportionate lack of resources devoted to the first two pillars of emergency management (prepare, mitigate) as opposed to resources allocated to response. Increased investment in preparedness and mitigation, done effectively, would inevitably decrease the significant draw on resources required by government to respond and recover from disaster events. 

To conclude, increased investment by governments in preparedness and mitigation should be made in partnership with communities and utilizing the knowledge of Indigenous and local stakeholders, consistent with the Sendai Framework. 

Our ‘new normal’ requires us as emergency management professionals to think and act differently about risk. How is your organization or government embedding an understanding of risk into new investments or developments?

I look forward to hearing your thoughts.