Botanical Gardens Emerge as the Most Effective Green Spaces for Cooling Streets During Heatwaves

In a thorough examination of research on the heat-mitigating attributes of green spaces during heatwaves, botanical gardens have emerged as the most effective.

The Global Centre for Clean Air Research (GCCAR) team, responsible for this finding, envisions that it will serve as valuable insight for policymakers tasked with planning cities in the face of a warming world.

The establishment of the Reclaim Network Plus signifies a global initiative bringing together planners, academics, city officials, charities and businesses.

This network aims to scrutinise the evidence regarding the advantages of incorporating green and blue spaces in urban planning.

The collective effort seeks to foster informed decision-making in shaping cities to combat the challenges presented by climate change.

The findings come at a critical juncture, prompting city planners and policymakers to consider the incorporation of more botanical gardens into urban planning strategies.

The urban heat island effect, exacerbated by the proliferation of concrete and asphalt in urban landscapes, leads to elevated temperatures in cities compared to their rural surroundings.

During heatwaves, this effect intensifies, posing severe health risks and discomfort to residents.

The study's revelation that botanical gardens are exceptionally effective in countering this trend brings renewed attention to the importance of green spaces in urban environments.

Prof Prashant Kumar, the study's lead author, said: "We have known for some time that green spaces and water can cool cities down.

"However, this study provides us the most comprehensive picture yet. What's more – we can explain why. From trees providing shade, to evaporating water cooling the air. The whole idea of the network is to promote the implementation of blue and green infrastructure in urban environments."

The study assessed temperature variations in various green spaces across major cities in the UK during heatwaves, including traditional parks, urban forests and botanical gardens.

The data revealed that botanical gardens consistently outperformed other green spaces in terms of temperature reduction and overall cooling effect.

City planners in the UK are now taking note of the study's recommendations, and considering the integration of more botanical gardens into urban planning initiatives.

This specific study discovered that locations like the Chelsea Physic Garden and the Royal Botanic Gardens at Kew in London, as well as the Gardens by the Bay in Singapore, effectively lowered air temperatures in the surrounding city streets by an average of 5 degrees Celsius during heatwaves.

Professor Maria de Fatima Andrade, a co-author of the report from the atmospheric sciences department at the University of São Paulo, Brazil, expressed, "Our paper affirms the multitude of methods available to stay cool.

"However, it also underscores the substantial work that remains. Institutions worldwide must allocate resources to targeted research because our study makes it evident that there is no universal solution. It depends on what proves effective for your community."

The role of botanical gardens extends beyond mere temperature regulation. Their rich biodiversity, educational value and contribution to mental well-being make them multifaceted assets for urban communities.

In addition to their cooling properties, botanical gardens provide habitats for diverse plant and animal species, foster environmental education and offer tranquil spaces for residents to connect with nature.

As cities grapple with the urgent need to adapt to the challenges of climate change, the study's findings serve as a clarion call for a reevaluation of urban planning approaches.

Botanical gardens, often seen as cultural and scientific institutions, are emerging as essential components of the urban landscape, offering a holistic solution to the complex problem of urban heat.

The integration of more botanical gardens into city planning not only provides a practical response to rising temperatures but also promotes biodiversity, education and well-being, contributing to the creation of healthier and more resilient urban environments for future generations.