Greening the Grey

In Canada, temperatures have risen at a rate roughly double the global average.

Vulnerable populations are at severe risk from extreme heat.

Without enough shade and resources, homeless individuals are up to 200 times more likely to die from heat-related causes compared to the general population. Credit: THE CANADIAN PRESS/Darryl Dyck.

Imagine a typical summer day in Vancouver's bustling downtown, the sun beats down mercilessly, transforming sidewalks into skillets and skyscrapers into radiators. This is the Urban Heat Island (UHI) effect, where city structures absorb and radiate heat, intensifying local temperatures and turning metropolitan areas into ovens.

UHI exacerbate climate change effects, leading to severe heatwaves, increased energy use, and heightened health risks, particularly for the vulnerable—our elderly, young, and economically disadvantaged.

In a city framed by ocean and mountains, where nature feels just a stone's throw away, it might seem surprising to confront such urban warmth. Yet, here we are, feeling the heat in places meant for respite from it. Vancouver's UHI challenges us to rethink our urban spaces—how can we cool our cityscape to make it not just bearable but beneficial for all its residents?

This map illustrates the stark temperature disparities across the city. Factors such as surface materials, their ability to reflect sunlight, and the presence of shading from tree canopies play an important role in these variations.
From City of Vancouver (2024).

Understanding the 3-30-300 Rule

In the context of Vancouver, applying the 3-30-300 rule could serve as a practical guideline to help address some of the UHI effects intensified by insufficient greenery.

Three Trees Visible from Every Home:

The first '3' in the 3-30-300 rule emphasizes that every residence should have at least three trees visible from the windows. Contact with natural elements in the living environment not only beautifies the urban landscape and improves air quality but also promotes residents' psychological health.

30% Tree Canopy Coverage in Communities:

The '30' indicates that each community should strive for 30% canopy coverage. Compared to communities with an excess of man-made surfaces, this level of greenery can improve the microclimate of the community and achieve the effect of reducing overall temperatures. Additionally, high canopy coverage provides important habitats for urban wildlife, contributing to biodiversity and ecological resilience.

Not More Than 300 Meters to the Nearest Park:

The final '300' suggests that no resident should be more than a 300-meter walk from substantial green spaces or parks. This proximity and accessibility encourage physical activity, promote community interaction, and ensure that everyone can enjoy the benefits of nature, reflecting a commitment to social equity and health.

The graphs in this section were created by Tasso Hu, author of this website.

In response to the pressing UHI effect, this study focuses on creating sustainable, livable urban environments through Nature-Based Solutions (NBS). It embarked on a targeted mission with three critical objectives:

Identify Hotspots

Pinpointing areas in Vancouver most susceptible to severe UHI effects, which often correlate with limited green space and high-density urban development.

Assess NBS Effectiveness

Evaluating how different nature-based interventions can mitigate these heat effects, enhance biodiversity, and improve urban livability.

Explore Green Equity

Understanding how the distribution of green spaces affects environmental and social equity, ensuring all communities benefit from urban greening.

Map of the City of Vancouver (British Columbia) and its 22 neighborhoods (except the UBC campus and Stanley Park). Credit: Gamesketcher

Group of People Enjoying Music Concert on the grass of a city park. Credit: Leah Newhouse

The Importance of Green Infrastructure in Urban Planning

Green spaces, tree canopies, and accessible parks are not just amenities but are fundamental to combating the UHI effect and enhancing urban life. The upcoming maps will visually represent our city’s current landscape of green infrastructure and highlight the disparities that need addressing. These visual tools showcase the potential for transformation through targeted NBS interventions.

From Vancouver Park Board (2020).

Urban Forest Canopy Coverage Map

This map provides a detailed view of where tree coverage meets or falls short of the city’s urban forestry targets. Areas with rich canopy are crucial in mitigating Urban Heat Island effects by providing shade and cooling urban temperatures. However, not all neighborhoods benefit equally. Areas with sparse canopy are more susceptible to heat, impacting community health and well-being, particularly during the warmer months.

Park Service Gaps Map

This map identifies major gaps in the availability of green space by highlighting locations in Vancouver without sufficient access to parks. Public health benefits greatly from accessible parks as they provide leisure areas that enhance both physical and mental health. However, these parks are not evenly distributed, and some communities find themselves more than 10 minutes' walk from the closest public green area. The first step in creating a more equal plan for the distribution of green space around the city is identifying the areas where these gaps occur.

The brief Sustainable urban and peri-urban forestry (UNECE, 2023) emphasizes the role of urban and peri-urban forestry in creating healthier, more resilient cities. It introduces the 3-30-300 rule, which serves as a practical framework for ensuring equitable access to urban forestry benefits. This document helps frame the analysis by highlighting the importance of maintaining a sufficient quantity and quality of green spaces accessible to all city residents. The data from this report shows the multifaceted benefits of urban forests in three broad areas: social, climate resilience, and economic benefits.

The potential of urban and peri-urban forestry. From UNECE (2023).

The potential of urban and peri-urban forestry. From UNECE (2023).

Explore how these gaps impact specific neighborhoods

Understanding the Aggregated Vulnerability Index
This index synthesizes diverse risk factors into a single metric, capturing the multi-dimensional nature of vulnerability. It incorporates data related to socio-economic stability, health susceptibility, and environmental exposure to outline areas at heightened risk. By Combining these facets, the index offers a comprehensive overview, pinpointing locales where interventions are most needed to bolster resilience.

Insights into the Local Restorative Nature Index
The LRN Index measures the healing potential of urban green spaces, emphasizing their role beyond mere aesthetics. It evaluates qualitative aspects like the variety and richness of plant species, the accessibility and usability of green areas, and the presence of water elements, which collectively enhance the urban experience. This index serves as a barometer for the psychological and recuperative benefits these spaces provide to urban populations, guiding city planners in crafting spaces that serve as sanctuaries within the cityscape.

Aggregated Vulnerability

Data derived from the Vancouver Park Board (2020), Statistics Canada (2021), and the City of Vancouver (2024). Analysis conducted by Tasso Hu.

Strathcona

^{Heat Vulnerability: Highest recorded summer temperatures in the city; limited green spaces exacerbate heat stress.}

^{Tree Canopy Coverage: Lowest in comparison to the city average, reflecting urban development pressures and insufficient green spaces.}

^{Green Space Accessibility: Limited and small parks within a 10-minute walk, significant gaps in park services due to dense housing and commercial blocks.}

^{Socio-Demographic Factors: High vulnerability due to a substantial proportion of low-income housing and limited access to cooling resources.}

Downtown Vancouver

^{Heat Vulnerability: Elevated temperatures due to high concentration of concrete structures and intense human activity.}

^{Tree Canopy Coverage: Moderately low, with gaps particularly in areas with high commercial and residential zoning.}

^{Green Space Accessibility: Moderate accessibility to parks; some residents lack green spaces due to urban layout.}

^{Socio-Demographic Factors: Moderate to high vulnerability, with a diverse population including transient residents and high-density living conditions.}

West End

^{Heat Vulnerability: Varied temperatures, cooler areas close to parks and shorelines.}

^{Tree Canopy Coverage: Generally meets canopy coverage targets, but ongoing monitoring and maintenance needed.}

^{Green Space Accessibility: Fair access to parks, fewer service gaps due to well-established parks and community gardens.}

^{Socio-Demographic Factors: Mixed vulnerability, both affluent residents and marginalized communities affected by heat waves.}

Southern Sunset

^{Heat Vulnerability: Higher temperatures inland, away from the cooling effects of ocean breezes.}

^{Tree Canopy Coverage: Below average, with residential areas having less green space than required for optimal cooling.}

^{Green Space Accessibility: Moderate, but new developments could impact this dynamic.}

^{Socio-Demographic Factors: Moderate vulnerability with a mix of single-family homes and higher-density neighborhoods.}

Marpole

^{Heat Vulnerability: Increased temperatures observed in commercial zones, compounded by sparse tree canopy.}

^{Tree Canopy Coverage: Slightly below average, with ongoing development affecting green space.}

^{Green Space Accessibility: Parks are accessible in certain areas, but access varies depending on proximity to main roads and housing types.}

^{Socio-Demographic Factors: Moderate vulnerability, particularly in areas with older infrastructure and less access to green space.}

The map from the LRN Index study (Devisscher et al., 2023) presents a bivariate analysis combining an aggregated vulnerability score with the index score across different neighborhoods in Vancouver. Areas depicted in deep pink, such as Strathcona, represent neighborhoods where the vulnerability of the population is high, while their exposure to restorative nature is very low.

The assessment reveals a consistent pattern:

neighborhoods with greater socio-economic challenges often experience both higher urban temperatures and insufficient tree canopy coverage.

Implementing Nature-Based Solutions in Vancouver

This grid showcases the various strategies employed, detailing their specific benefits and real-world applications.

	Tree Planting	Urban Parks	Rain Gardens	Green Roofs	Permeable Pavements
Representative photo
Cooling Benefits	Notable decrease in local temperatures by providing shade	Large green spaces significantly cool urban areas	Moderate cooling through water absorption and evaporation	Provides thermal insulation for buildings	Lower surface temperatures by allowing water to percolate
Biodiversity Enhancement	Supports a diverse range of flora and fauna	Acts as urban biodiversity hubs	Creates habitats for local wildlife	Can host a variety of plant species	Supports groundwater recharge
UHI Reduction	Reduces surface and air temperatures effectively	Offers extensive cooling through evapotranspiration	Helps manage stormwater, reducing thermal retention in pavements	Reduces heat absorption by buildings	Reduces runoff and heat accumulation on surfaces
Community Impact	Enhances aesthetic appeal and provides community gathering spaces	Promotes physical activity and mental well-being	Educates the public on sustainable water management	Increases green space without using land	Improves urban water cycles and reduces flood risks

Based on the comprehensive data analyzed, and considering both the economic costs and mitigation effectiveness, the study identified the most suitable methods for addressing UHI effects in Vancouver’s five most impacted communities. These methods include tree planting, the development of urban parks, and the implementation of rain gardens.

Impact Assessment

Environmental Impact

NBS leads to cooler city temperatures and reduced energy usage. These solutions also support urban biodiversity and enhance ecosystem health. Effective stormwater management, facilitated by features like rain gardens and permeable pavements, helps decrease runoff and urban pollution.

Social Impact

Green spaces provide natural areas for recreation and relaxation, important for mental health and community well-being. They offer venues for physical activity and serve as community gathering spots, which help reduce stress and foster social connections among residents. Moreover, the City's increasing urbanization adds the urgency to integrating diverse perspectives into sustainable urban planning.

Economic Impact

Investments in NBS are linked to increased property values and can reduce healthcare costs by alleviating heat-related health issues. Green spaces boost local tourism and stimulate economic activity in surrounding areas. They can also lower municipal expenses by reducing the demand for engineered cooling and extensive stormwater systems.

Strategic Recommendations

✅Dynamic Monitoring

Invest in higher-resolution datasets and regular updates to keep pace with urban changes. Use advanced technologies like machine learning to predict and respond to land use changes dynamica

✅Community Engagement

Increase community involvement in urban planning through participatory data collection. This will ensure that solutions are tailored to the specific needs and preferences of local residents.

✅Adaptation of Standards

Align urban planning efforts with the 3-30-300 rule to ensure equitable access to green spaces. Regularly review and adjust these benchmarks to reflect the evolving urban landscape.

Please take a moment to participate in our survey

This survey aims to gather your feedback on local green initiatives, your suggestions for future projects, and your interest in participating in community greening activities

For a deeper dive into the research and to view the full report, please follow the link below

Thank you for your exploration. We hope these resources will inspire further research and action towards a cooler, greener Vancouver!

References

Berland, A., Shiflett, S. A., Shuster, W. D., Garmestani, A. S., Goddard, H. C., Herrmann, D. L., & Hopton, M. E. (2017). The role of trees in urban stormwater management. Landscape and Urban Planning, 162(C), 167-177. https://doi.org/10.1016/j.landurbplan.2017.02.017

Beugin, D., Clark, D., Pelai, R., Ness, R., Miller, S., & Wale, J. (2023). The case for adapting to extreme heat: Costs of the 2021 BC heat wave. Retrieved from https://climateinstitute.ca/wp-content/uploads/2023/06/The-case-for-adapting-to-extreme-heat-costs-of-the-BC-heat-wave.pdf

City of Vancouver. (2024). Climate change adaptation strategy. Retrieved from https://vancouver.ca/files/cov/vancouver-climate-change-adaptation-strategy-2024-25.pdf

Devisscher, T., Lam, T., Fitzgibbons, J., Jarvis, I., Li, D., & Mitchell, M. G. E. (2023). More than greening: Using a novel index to assess restorative nature and vulnerability relationships. Ambio, 52(12), 1992-2008. https://doi.org/10.1007/s13280-023-01889-2

European Environment Agency. (2020). Who benefits from nature in cities? Retrieved from https://www.eea.europa.eu/publications/who-benefits-from-nature-in

Hayes, A., Jandaghian, Z., Lacasse, M., Gaur, A., Lu, H., Laouadi, A., Ge, H., & Wang, L. (2022). Nature-based solutions (NBSs) to mitigate urban heat island (UHI) effects in canadian cities. Buildings (Basel), 12(7), 925. https://doi.org/10.3390/buildings12070925

Health Canada. (2010). The Urban Heat Island Effect: Causes, Health Impacts and Mitigation Strategies. https://www.canada.ca/en/health-canada/services/environmental-workplace-health/reports-publications/climate-change-health/climate-change-health-adaptation-bulletin-number-1-november-2009-revised-december-2010-health-canada-2009.html

Li, Y. (2022). Effectiveness of Urban Green Infrastructure: Management Challenges in the City of Vancouver, British Columbia. https://lfs-mlws-2020.sites.olt.ubc.ca/files/2023/04/liying_11776_21988805_Final_Ying-.pdf

Rupard, M. (2019). Urban Heat Islands: Causes, Impacts, & Mitigation. Retrieved from https://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1200&context=crpsp

Statistics Canada. (2021). Latest Population Density Map. Retrieved from https://www12.statcan.gc.ca/census-recensement/2021/geo/maps-cartes/thematicmaps-cartesthematiques/pd-pl/files-fichiers/2021-92173-001-933-013-02-00-eng.pdf

United Nations Economic Commission for Europe (UNECE). (2023). Sustainable urban and peri-urban forestry. Retrieved from https://unece.org/sites/default/files/2023-03/Urban%20forest%20policy%20brief_final_0.pdf

U.S. Environmental Protection Agency. (2023). Learn About Heat Islands. Retrieved from https://www.epa.gov/heatislands/learn-about-heat-islands

Vancouver Park Board. (2020). VanPlay Strategic Bold Moves - Equity Chapter. Retrieved from https://vancouver.ca/files/cov/vanplay-strategic-bold-moves-equity-chapter.pdf

Wolch, J. R., Byrne, J., & Newell, J. P. (2014). Urban green space, public health, and environmental justice: The challenge of making cities ‘just green enough’. Landscape and Urban Planning, 125, 234-244. https://doi.org/10.1016/j.landurbplan.2014.01.017

COOLING VANCOUVER WITH NATURE

Background: Drone Shot of Buildings in the City of Vancouver; Credit: John Paul Tougan