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.

What Wildfire Evacuees Need. Right Now.

Currently in California and Oregon, mass evacuations are underway as a result of three of the nine largest wildfires in that state’s history.

As an emergency responder on the Regional Municipality of Wood Buffalo (RMWB) Wildfire, (commonly known as the Fort McMurray Fires), I had a front-row seat to the largest evacuation in Alberta’s history, with upwards of 90,000 people displaced from their homes and 3,244 structures destroyed. Economic costs as a result of the fires were among the highest in Canadian history to date, with insured property damage estimated at $3.58 billion.

A common feature of disaster season over the past number of years has been the devastating impact of wildfires, and severe economic and environmental consequences as a result. According to Natural Resources Canada, climate change and climate variability have altered patterns of lightning, temperature, precipitation and vegetation. These altered conditions have increased the potential for fire, with some estimates suggesting a doubling of the area burned by the end of the century.

According to some reports, communication gaps contributed to mixed messages to residents regarding the need to evacuate, while others have highlighted how the rapid escalation of the fire overwhelmed the ability to respond. In order to continue to develop best response practises, it is worth considering the unique requirements of evacuees, including the method, breadth and timeliness of information dissemination.

Issues surrounding internal EOC communications, including field interoperability and technology will be covered in a future post.

Information requirements for wildfire evacuees was studied in an article by S.M. McCaffrey et. al. in the International Journal of Mass Emergencies and Disasters published in 2013. The recommendations outlined in this report reference the residents affected by wildfires in Arizona and Colorado in 2010, but have obvious applicability to future events of this type.

As expected, the authors of the study found that those most impacted by a wildfire event would have the greatest need for information, particularly regarding evacuation, road closures, protection of property and disaster recovery. Previously evacuated survey respondents reflected a common concern that critical information was not provided by authorities in a timely manner. In practise, this lack of timely information provides fertile ground for misinformation to spread, particularly on social media. 

Evacuees have access to multiple information sources. The study’s findings show that evacuees gravitate away from static sources (i.e. radio) towards those that incorporate two-way communication, as in social media. The increased functionality of social media allows evacuees to seek and source locally specific information that may not be available in traditional formats. 

As emergency management professionals, how can we ensure that evacuees have access to information in as timely a manner as possible? The review of literature and anecdotal evidence highlights important trends and lessons that may be applied to future hazards: 

  • Early establishment of credibility. It is important that updates and information be vetted and distributed through the PIO, reporting to the Incident Commander. A ‘bias for candor’, established early in the crisis will go a significant way towards establishment of trust and compliance with subsequent orders.
  • Criticality of consistent, centralized communication. While disruptions, distress and tension cannot be ameliorated completely, it is critical to ensure a coordinated approach to messaging. Establishing early credibility and transparency, from a source deemed credible, goes a long way towards reducing the risk of the disaster becoming ‘weaponized’ by those seeking to spread mis/disinformation.
  • Telling the truth. Most people can handle the truth, it is the obfuscation and withholding of information that does a great deal of damage. Understandably, Command Staff are reluctant to release information that may cause further distress to those affected. Paradoxically, this ‘bias for candor’ but may reduce the risk associated with those who would seek to assess property damage on their own.
  • Demonstrating empathy. In a response scenario where “all hell is breaking loose”, it is sometimes hard to remember the people we are serving, in many cases, are having the worst day of their lives. As the saying goes, “ Before people will listen to you, they need to know you care about them.” To this end, employing social media monitors, to engage in a two-way dialogue with affected individuals offering psychosocial supports is a critical element of the response.

In a disaster scenario, emergency responders are wise to invest in resources and initiatives that may assist impacted individuals with factual, empathic and transparent communications.

I look forward to hearing your input. Any feedback or questions can be directed to me at @AlisonPoste on Twitter, or to AlisonPoste@gmail.com.