As the global climate crisis accelerates and the climate rapidly changes, it becomes crucial for urban planners and environmentalists to rethink and reengineer the spaces we inhabit and traverse daily, ensuring that our cities remain livable, sustainable, and resilient. The streets in our cities are vital parts of our neighbourhoods, allowing people to move around, do business, and connect with each other. Yet, they are often overlooked when we discuss climate adaptation and sustainability.

One of the most promising approaches emerging from this intersection of urban planning and environmental science is the integration of Nature-based Solutions (NbS) into the design and structure of our streets.

But what makes NbS so powerful, and how can they transform our urban landscapes into climate-resilient havens?

What are Nature-Based Solutions (NbS)?

Nature-based Solutions (NbS) refer to strategies and actions that harness the power of nature to address societal challenges, such as climate change, water security, and biodiversity loss. These solutions aim to support and work in tandem with natural processes to deliver benefits for both the environment and human well-being. Examples of NbS include:

• Restoring wetlands to improve water quality and reduce flood risks.

• Planting urban forests to sequester carbon, reduce urban heat island effects, and enhance biodiversity.

• Implementing agroforestry practices to improve soil health, increase biodiversity, and enhance crop yields.

• Creating green roofs and green living walls in urban areas to reduce energy consumption and improve air quality.

Whether it's the carbon-sequestering capabilities of trees or the water-absorbing nature of wetlands, NbS taps into these natural "superpowers" to benefit both the environment and urban communities. Additionally, with the growing emphasis on Biodiversity Net Gain (BNG), urban projects are now aiming not just to preserve, but to enhance biodiversity, ensuring that developments leave nature in a better state than before.

There are a number of overlapping definitions of what Nature-based Solutions are. For a comprehensive understanding of NbS, you can consult publications from the International Union for Conservation of Nature (IUCN) and the United Nations.

What are climate-resilient streets? 

Climate-resilient streets, on the other hand, specifically focus on designing and adapting urban streets to cope with the impacts of climate change. These streets incorporate elements that can withstand and adapt to climate-related challenges such as extreme temperatures, heavy rainfall, and flooding. While they often employ Nature-based Solutions, their primary goal is to make urban infrastructure more resilient to climate impacts. Examples include:

• Incorporating rain gardens, swales, and Sustainable Drainage Systems (SuDS) to manage water distribution and reduce flood risks.

• Using permeable pavements to allow water to seep through, reducing surface runoff and preventing flooding.

• Planting trees along streets to provide shade, reduce urban heat, and absorb rainwater.

Climate-resilient streets employ ‘green’ features like trees, green roofs, living walls, green screens and porous pavements, which not only capture carbon but also provide shade. 

Meanwhile, ‘blue’ elements such as SuDS, rain gardens, Swales (shallow, broad and vegetated channels designed to store and/or convey runoff), retention basins, and specially designed water channels help manage water distribution and reduce flood risks. 

At its core, a climate-resilient street is designed to withstand and adapt to the changing climate conditions. It's not just about laying down tarmac and planting a few trees. It's a holistic approach that considers water management, urban heat, biodiversity, and the well-being of residents.

The Role of Nature-Based Solutions (NBS) in Street Design - The positive effects of Climate-resilient streets

1. Flood Management: Traditional concrete pavements often lead to water runoff, contributing to urban flooding, while NbS, such as permeable pavements and rain gardens, enable water percolation, reduce runoff, and recharge groundwater. By incorporating permeable pavements and rain gardens, these streets can effectively absorb and manage rainwater, mitigating the risk of urban flooding.

2. Temperature Regulation: Urban areas often suffer from the "heat island" effect, where concrete and asphalt absorb and radiate heat. Trees and green roofs, integral parts of NbS, provide shade, reduce ambient temperatures, and, through strategic planting and green spaces, help combat the urban heat island effect, making our cities more bearable during heatwaves.

3. Biodiversity Boost: Incorporating native plants, creating habitats, and designing green spaces in streetscapes can attract a range of wildlife, from birds to beneficial insects, thus enhancing urban biodiversity.

4. Improved Air Quality: Trees and plants act as natural air filters, absorbing pollutants and releasing oxygen, leading to cleaner, fresher urban air.

5. Enhanced Well-being: Green, pleasant streets encourage walking, cycling, and outdoor activities, promoting both physical and mental health.

Differences Between Nature-Based Solutions and Climate-Resilient Streets

1. Scope: NbS encompasses a broad range of strategies and actions across various ecosystems and landscapes, from forests to coastal areas. Climate-resilient streets specifically target urban street infrastructure.

2. Objective: While both aim to address the challenges of climate change, NbS has a broader goal of enhancing ecosystem health, biodiversity, and human well-being. Climate-resilient streets focus on making urban areas more adaptable to climate-related events.

3. Implementation: NbS can be implemented in various settings, including rural, peri-urban, and urban areas. Climate-resilient streets are specific to urban and suburban settings.

4. Examples: Restoring a mangrove forest to act as a natural barrier against storm surges is an example of NbS. In contrast, redesigning a city street with permeable pavements and rain gardens to manage water runoff is an example of a climate-resilient street.

In summary, while there's overlap between Nature-based Solutions and climate-resilient streets (as the latter often employs the former), the two concepts differ in their scope, objectives, and areas of implementation. Both, however, play crucial roles in addressing the challenges posed by climate change and ensuring a sustainable future.

Challenges and Opportunities

While the benefits of integrating NbS into street design are diverse, challenges remain. These include initial investment costs, maintenance considerations, and the need for interdisciplinary collaboration between urban planners, ecologists, and communities. However, the long-term benefits - from reduced climate-related damages to enhanced community well-being - make a compelling case for the widespread adoption of NbS in urban street design.

The Future of Climate-Resilient Streets

As the impacts of climate change become increasingly pronounced, the need for adaptive and forward-thinking urban solutions grows. Nature-based solutions, with their dual benefits for the environment and urban citizens, offer a promising path forward. By integrating NbS into our streets, we not only make them more resilient to climate challenges but also transform them into vibrant, sustainable, and harmonious spaces that echo the rhythms of nature.

In conclusion, the power of Nature-based Solutions lies in their ability to bridge the gap between urban living and the natural world, crafting streets that are not only resilient to the challenges of our changing climate but also teeming with life, beauty, and community spirit.