Green spaces matter - why Landscape Architecture is at the forefront of the fight against climate change

Climate change is mainly caused by human activities. How can landscape architects and urban designers reshape spaces and systems to enable changes in human behaviours that will in turn reduce the carbon footprint of the individuals who exist in a city, live in a neighbourhood or visit a space? It can be more than just planting, installing new green infrastructure and thinking about materiality and its upstream and downstream impact.

What we need is big scale ideas to tackle climate change and ensure different places have different approaches.

This can be a two-prong approach - mitigation and adaptation;

To help mitigate climate change landscape architects have a number of strategies to call on. Mitigation, is slowing down global warming by reducing the concentration of GHG’s within the atmosphere. It is something that as designers we can implement at varying scales and enable by introducing and encouraging new behaviours through efficient design.

Planting is obviously the most well known landscape architectural means for mitigating climate change. Plants are powerful tools to sequester carbon. The type of plants selected for a certain environment, the way they are positioned, and how they are maintained are vital components in determining the actual carbon sequestration potential of different landscapes. When we also plant, thinking about pollinator friendly vegetation is also important. It preserves the very ecosystems and species we are trying to protect.

Appropriate and proper soil management is another effective form of mitigation. Soil is a powerful tool which if healthy can capture and hold carbon, which means it must be looked after and managed if it is to realise its sequestration potential. Soil rehabilitation in large natural spaces and of course in agricultural land can remove carbon from the atmosphere and of course generate resilience to drought. Healthy soils in agriculture also equates to healthier food. Currently the practical implementation of soil carbon strategies at a large scale lags behind its potential.

Transport is a major contributor to both air pollution and carbon emissions; often being responsible for over a third of a city’s carbon emissions. When thinking of large scale ideas and projects, landscape architects and urban designers have capacity to work collaboratively with local authorities, clients and transport planners to realise a well integrated sustainable transport system, which also includes effective micro-mobility networks and of course improved walkability. A new large scale movement system also preserves city centres and opens up new urban neighbourhoods, often removing non-essential motorised traffic to create more accessible, future proofed and liveable places. Getting people out of private vehicles and into other modes of transport is integral to cities achieving their net zero goals.

When a transport journey works well, it becomes a positive experience within a city and helps a city or neighbourhood become economically productive. The cyclist and pedestrian are often the biggest players here. Their journey experience is crucial to leaving people with a positive experience of a city. How often do you hear people returning from a city with good walkability and bicycle networks with glowing reports of how liveable the city was and how enjoyable it was to visit?

Climate change is already here. Globally we are experiencing the consequences of intense floods and precipitation events, sea level rise, droughts, and heat waves that will continue to increase over the coming decades.

Landscape architects can help communities adapt and be resilient to these changes in a variety of ways.

When oceans get warmer; it means more storms, and when storms move over warmer waters; the intensity of the storm increases; as does the wind intensity. Global warming relocates precipitation in an unpredictable way; which also leads to more drought and unseasonal weather events.

Managing water effectively will be a significant challenge as the atmosphere and our seas continue to increase in temperature. Extreme precipitation events on the coast has highlighted the risk of densely populated cities and vulnerable communities being there. Coastal flooding coupled with sea level rise will threaten communities across the globe.

In the last decade we have seen a variety of projects emerge out of the US’s Rebuild by Design initiative, some of which are currently under construction. These projects which include breakwater systems which also act as new natural habitats demonstrate the unique role design can play in protecting coastal communities against flooding, and offer an exciting alternative to old school attempts at managing similar weather events with walls, concrete, and asphalt.

Landscape architects also play a key role in managing flooding threats in catchment areas and near natural inland water bodies. In effect we need to replicate the hydrologic cycle and daylight stormwater systems, and in doing so it gives us opportunity to create new riparian habitats. We also need more nature based solutions and to make landscaped surfaces more permeable and create new green infrastructure to manage, slow down, infiltrate and attenuate stormwater runoff.

We need to be in sync with our natural system and turn our cities into sponges.

In the last decade we have seen a variety of projects emerge out of the US’s Rebuild by Design initiative, some of which are currently under construction. These projects which include breakwater systems which also act as new natural habitats demonstrate the unique role design can play in protecting coastal communities against flooding, and offer an exciting alternative to old school attempts at managing similar weather events with walls, concrete, and asphalt.

Landscape architects also play a key role in managing flooding threats in catchment areas and near natural inland water bodies. In effect we need to replicate the hydrologic cycle and daylight stormwater systems, and in doing so it gives us opportunity to create new riparian habitats. We also need more nature based solutions and to make landscaped surfaces more permeable and create new green infrastructure to manage, slow down, infiltrate and attenuate stormwater runoff.

We need to be in sync with our natural system and turn our cities into sponges.

Heat is another growing threat posed by the warming of the planet’s average surface temperature. Higher than normal temperatures are becoming more regular and extensive; creating risk for communities who are not used to extreme heat. The heat also prolongs drought while it also increases risk of intense and extreme wildfires and causes greater water evaporation in regions where there is already water scarcity.

Thinking about the urban heat island is something that needs considered thought. There are a number of strategies that can be implemented to improve thermal comfort in urban areas. Employing shade systems, new green infrastructure, water cooling systems and selecting low albedo materials all make a difference. Combining these strategies can reduce the temperature of a hot urban space by 10° to 12°Celcius.

Over the last decade there has been mass losses in biodiversity due to seasonal shifts, changing temperatures, new rainfall patterns, and extreme weather events. Added to this other human activities such as pollution and general environmental vandalism has damaged natural habitats; meaning that countless species have migrated to seek sanctuary in new locations.

Large scale projects and masterplans have the capacity to be havens for wildlife and are an opportunity to preserve and create new ecological infrastructure for vulnerable species. We need to take a holistic approach that places ecology at the heart of our design. It includes interventions to manage invasive species, restore wetlands, protect critical natural water sources, and enhance wildlife connectivity, while also considering improving access for the general public so they can be connected to nature.

By incorporating climate-resilient designs, such as water-efficient landscapes, urban green spaces, and sustainable stormwater management systems, landscape architects can contribute to reducing heat island effects, improving air quality, and enhancing overall environmental resilience. They can also collaborate with urban planners, architects, and policymakers to create climate-conscious urban designs that prioritize sustainability and adaptability.

Furthermore, landscape architecture can contribute to raising awareness about the importance of preserving natural ecosystems, promoting sustainable land use practices, and fostering community engagement in climate change mitigation and adaptation efforts.

Overall, landscape architecture's unique position to blend design, ecology, and sustainable principles makes it a valuable profession in tackling the challenges posed by climate change.

References

Columbia University Earth Institute

www.earth.columbia.edu

Landscape Architecture Foundation

www.lafoundation.org

NASA; Global Climate Change

www.climate.nasa.gov

The Climate Change Review, Ethan Olson, 2022

www.theclimatechangereview.com

The Landscape Institute, 2021

www.landscapeinstitute.org/blog/australian-landscape-architects-make-difference-climate-positive-design

United Nations Climate Change

www.unfccc.int/process-and-meetings/the-paris-agreement

Image Credits

Figure 3; Dissing + Weitling, Bicycle Snake, Copenhagen.

Figure 4; SCAPE Landscape Architecture, 'Living Breakwaters', New York.

Figure 7; PNAS