Posted by Ben Gooden on Fri, Jun 09, 2023 @ 6:04 AM
In this article, we delve into the intricate relationship between urban heat and vulnerable populations, shedding light on how extreme heat events disproportionately affect those who are already marginalized. Vulnerable populations encompass a diverse range of individuals, including low-income communities, the elderly, children, and others with limited resources or specific vulnerabilities. These groups face unique challenges when it comes to coping with the intensified heat in urban areas, making it imperative to explore the negative aspects of urban heat’s impact on their lives.
What is Urban Heat?
Often referred to as the urban heat island (UHI) effect, is a phenomenon that has become increasingly prevalent in our rapidly urbanizing world. It occurs when urban areas experience significantly higher temperatures than their surrounding rural areas due to various human activities and modifications to the environment. Urban heat is primarily driven by factors such as the concentration of buildings, concrete surfaces reflecting heat, and reduced green spaces and trees in cities.
Why is Urban Heat an Issue?
The significance of urban heat extends far beyond the discomfort of sweltering summer days. It has emerged as a pressing concern with multifaceted implications, touching on areas ranging from public health to environmental sustainability. As global temperatures continue to rise due to climate change, urban heat exacerbates the challenges faced by cities and their residents. Understanding its impacts, especially on vulnerable populations, is crucial for building resilient and equitable communities.
What are the Negative Impacts of Urban Heat?
Urban heat, while an avoidable consequence of urbanization, brings with it a host of negative consequences that cannot be ignored. In this section, we delve into two primary aspects of the negative impact of urban heat: health implications and environmental consequences.
Health Implications of Urban Heat
- Increased Risk of Heat-Related Illnesses: Urban heat creates a hazardous environment, particularly during heatwaves. The elevated temperatures can lead to a surge in heat-related illnesses, including heat exhaustion and heatstroke. Vulnerable populations, such as the elderly and those with pre-existing health conditions, face heightened risks. The negative effects on human health can be severe, sometimes even fatal.
- Impact on Vulnerable Groups: Vulnerable groups within urban areas are disproportionately affected by the health risks posed by urban heat. Elderly individuals, who often have reduced heat tolerance and limited mobility, find themselves at greater risk. Similarly, children are more susceptible to heat-related illnesses, and the inability to access air conditioning in many low-income neighborhoods exacerbates their vulnerability.
We recently held an event on the impacts on urban heat in Penrith which in 2020 was recorded as the hottest place on earth reaching a sweltering 48.9C . We invited General Practitioner Dr. Kim Loo from ‘Doctors for the Environment‘ out to speak about the social and medical impacts lack of trees and greenery were having on her patients out in Western Sydney.
Environmental Consequences of Urban Heat
Stress on Urban Ecosystems: Urban heat exacerbates the stress on already fragile urban ecosystems. Elevated temperatures can damage vegetation and urban green spaces, leading to reduced biodiversity and aesthetic degradation. These effects undermine the capacity of cities to provide green areas for recreation and to mitigate the urban heat island effect
Aggravation of Air Pollution: Urban heat exacerbates another urban challenge: air pollution. Higher temperatures can increase the formation of ground-level ozone, a major component of smog, and can intensify the emissions of pollutants from vehicles and industrial sources. This combination of heat and pollution further deteriorates air quality, posing serious health risks to urban residents.
Understanding the negative consequences of urban heat is essential to formulating effective strategies for mitigating its impact on vulnerable populations. As we proceed, we will explore how these challenges can be addressed through various initiatives and interventions at both the community and policy levels.
Vulnerable Populations and Urban Heat
Urban heat doesn’t discriminate, but its effects are disproportionately felt by certain segments of the population. In this section, we delve into the specific vulnerabilities of different groups and examine how urban heat impacts their daily lives.
- Lack of Access to Air Conditioning: For many low-income households in urban areas, access to air conditioning is a luxury they cannot afford. This lack of access means that during extreme heat events, residents must endure dangerously high indoor temperatures, putting their health and well-being at risk. As a negative consequence, energy bills can skyrocket when individuals do use air conditioning, leading to financial strain.
- Limited Green Spaces: Low-income neighborhoods often lack green spaces and tree cover, which can act as natural coolants. The absence of parks and greenery leaves residents with fewer options for seeking refuge from the heat. These communities are disproportionately exposed to the urban heat island effect, exacerbating the challenges they face during heatwaves.
- Health Risks Due to Reduced Heat Tolerance The elderly are particularly vulnerable to the negative impacts of urban heat due to reduced heat tolerance. As people age, their bodies become less efficient at regulating temperature, making them more susceptible to heat-related illnesses such as heat exhaustion and heatstroke. The lack of climate-controlled environments can pose serious risks to their well-being.
- Social Isolation During Heatwaves During extreme heat events, elderly individuals may be reluctant to leave their homes, leading to social isolation. This isolation can have adverse effects on mental and physical health. Connecting with support systems becomes challenging when venturing outside is uncomfortable or even dangerous.
Children and Schools
- Impact on Learning Environments Schools are not immune to the effects of urban heat. Increased temperatures can create uncomfortable and distracting learning environments for students. Concentrating on studies becomes difficult when classrooms lack proper cooling, impacting the educational experiences of children.
- Heat-Related School Closures In some cases, extreme heat can lead to the closure of schools, disrupting the routines of both students and parents. Such closures can result in lost instructional time and place an additional burden on parents who may need to arrange for alternative childcare during these closures.
- Children and Babies: Children and babies are especially vulnerable to heat due to being unable to effectively protect themselves from the heat without assistance. From a combination of physiological factors, limited coping mechanisms, and their inability to effectively protect themselves from extreme heat.
Understanding how urban heat uniquely affects these vulnerable populations is essential for crafting targeted interventions and policies aimed at mitigating the disparities in heat-related risks and impacts. In the following sections, we will explore strategies and initiatives that can help alleviate these challenges and create more equitable and resilient urban environments.
Case Study: Urban Heat Islands a Huge Problem
South Australia is notoriously hot but some parts of Adelaide are sweltering more than ever. Not surprisingly, these are the suburbs that contain “urban heat islands” leading to higher than average temperatures compared to neighbouring suburbs. You may think what difference does a few degrees make? Well, as it turns out, a lot – with these suburbs often coinciding with higher levels of vulnerability, including illness and death, especially amongst the elderly.
Former aged care worker Wendy Farmilo, 75, lives in Tranmere near Campbelltown in suburban Adelaide — an area overrun with urban heat islands. Ms Farmilo said because of cooling measures she has put in place she has managed to avoid the full brunt of the weather but is urging others to take precautions. “Older people do not drink enough water, they get dehydrated… they feel if they drink too much they might have a bladder problem,” she said.
According to a report prepared by consultancy firm Edge South Australia, nearly all of the heat islands in Ms Farmilo’s council are also home to society’s most vulnerable. “Urban heat is one of the biggest killers of people in our community, more so than any other natural hazard,” Edge SA General Manager Dr Mark Siebentritt said. “One of the big strategies we can use to tackle that is the planting of more trees. Councils right around South Australia are planting more trees than ever before.”
Landscape Architect and green space advocate Daniel Bennett said boosting tree cover would reduce heat, as well as improving “mental and physical wellbeing. Increasing the city’s connected tree canopy is one way to achieve a reduction in local temperatures as well as reducing the urban heat island effect.”
One thing is clear – as temperatures continue to soar, urban trees are not just a nice-to-have. They’re literally a matter of life and death.
How do we Reduce the Urban Heat Island?
Reducing the impact of urban heat is a multipronged approach with the potential to enhance urban livability, improve public health, mitigate climate change, and foster greater resilience in our cities.
Increasing the number of parks, green roofs, and urban vegetation can significantly reduce the UHI effect. Trees and plants provide shade and release moisture through a process called transpiration, which cools the surrounding air. This helps create a more comfortable microclimate and reduces the heat absorbed by concrete and asphalt surfaces.
Positive 2: Enhanced Aesthetics and Quality of Life
Expanding green spaces not only mitigates the UHI but also enhances the aesthetics and quality of life in urban areas. Parks and greenery provide recreational opportunities, improve air quality, and create more pleasant and inviting environments for residents and visitors.
Positive Strategy 2: Cool Roof Initiatives and Reflective Surfaces
Positive 1: Reduced Heat Absorption
Cool roof initiatives involve using reflective materials or coatings on roofs to reduce heat absorption. These roofs reflect more sunlight and absorb less heat, helping to lower temperatures in urban areas. This can be particularly effective in reducing indoor temperatures and energy consumption in buildings.
Positive 2: Energy Efficiency and Cost Savings
Cool roofs can lead to significant energy savings by reducing the need for air conditioning during hot weather. This not only lowers electricity bills for building owners but also decreases the overall energy demand in cities, contributing to sustainability goals and reducing greenhouse gas emissions.
Tackling Urban Heat in Practice
To see how local governments are combating the impact of urban watch Sustainability and Resilience Coordinator Belinda Atkins from Penrith City Council talk about their ‘Cooling the City’ Strategy and the people first outlook they have when tackling urban heat.