Learn from nature to become more resilient

WSP’s Ludo Pittie reflects on how cities can learn from nature to become more resilient.

Ludo Pittie is head of landscape architecture and urban design at WSP.

With COP27 and COP15 behind us, many policymakers and businesses are now reflecting on the agreements made and how to adapt our urban infrastructure to be more resilient to our changing climate. 

With over half of the world’s population living in urban areas, cities are high energy consumers and produce more than 60% of global greenhouse gas emissions. However, they are also the social, economic, and political hubs of society and are particularly vulnerable to the effects of climate change. 

Adapting our cities to be more resilient is vital to enhance sustainability and nurture a strong sense of community for urban citizens. 

Placing nature at the heart of planning decisions could be the solution for more sustainable and resilient urban development. Unlike cities, nature has evolved over millions of years and can provide many valuable insights into how to develop a thriving urban ecosystem.

For example, nature-based solutions can support greater water resilience in cities. In a concrete jungle, pavement and concrete are not only resource and carbon intensive to make but also increase urban temperatures, flooding and water pollution. 

Grounding cities in soil can respond to these effects. By increasing permeability with porous materials and sustainable drainage systems, such as swales and raingardens, not only can streets and urban courtyards better retain rainwater to reduce flooding and stormwater pollution, but they can also strengthen biodiversity and serve as beautiful, restorative spaces for community enjoyment.

"By acknowledging the interconnected nature of cities, we can design our urban spaces to meet the needs of both the natural environment and the people that call them home."

If you look up in a city, its buildings will capture your imagination. Just as a city’s buildings support the social, economic and political lives of thousands of individuals, a forest’s trees similarly serve as a home for a variety of plants and animals.

However, while trees continue to nurture new life after death, providing shelter, habitat and nutrition, buildings are rarely repurposed once vacated. Over 10% of the world’s total carbon emissions come from materials and construction of buildings alone; by continuing to demolish buildings that could be partially reused or retrofitted, developers ignore the embodied carbon emissions that come with building anew. 

Instead, to reduce this cost, we should adapt buildings or vacant sites for new uses and recycle existing materials for reuse on new developments on-site or elsewhere. 

Moreover, how can we make existing buildings more effective and efficient? The forest canopy is complex: it is the most biodiverse part of the forest, moderates temperatures below and captures the greatest amount of energy. We already collect energy on rooftops, but when combined with a green roof, solar panels are on average over 3% more efficient. 

A green roof also reduces energy usage, can enhance biodiversity and be used for social activities too, all of which are beneficial in reducing operational carbon emissions. 

As we see the continual decline of biodiversity globally, the importance of cities to protect nature cannot be ignored or neglected. 

While we are used to thinking of the natural and built environments as distinct opposites, our cities are dependent on nature for their success, so it is vital that we recalibrate our approach to urban building so our cities are better aligned with the natural world.  

Cities around the world are already considering how to integrate nature with urban environments. In the UK, for example, the 2021 London Plan emphasizes the importance of high quality urban green infrastructure for the capital’s development, with the Urban Greening Factor helping local councils implement these nature-based solutions. 

Fundamentally, to adapt to the demands of the future, we must think of cities as part of a wider network, in a similar way to a forest where everything works together to create a thriving, healthy environment. 

Understanding how these different elements interact can inform how we design adaptive communication, transportation and energy networks of the future. Can we explore how a building can have multiple sustainable uses? How can energy captured by green roofs be used by local micro grids, power electric buses or underground rail?

By acknowledging the interconnected nature of cities, we can design our urban spaces to meet the needs of both the natural environment and the people that call them home.

Ludo Pittie is head of landscape architecture and urban design at WSP.

If you would like to contact Rob O’Connor about this, or any other story, please email roconnor@infrastructure-intelligence.com.