Designs for a green skyscraper that could remove up to 1,000 tonnes of carbon from the atmosphere on an annual basis — the equivalent to growing 48,500 trees — was unveiled at the COP26 conference last week.

Named for the world’s tallest trees, the ‘Urban Sequoia’ design is the brainchild of the Chicago-based architectural firm Skidmore, Owings & Merrill and is based on technologies that are all available for use today.

Multiple methods would be used to store carbon in high rises, such as construction using carbon-absorbing material, the growth and harvesting of plants, algae, fuel and energy, and air capture.

This would be made possible by the tower’s “stack effect”, which draws in air into the center of the building to process a carbon extraction. It also contributes to the building’s net zero-energy system.

In fact, the company has claimed their Urban Sequoia tower design would be capable, assuming a lifespan of at least 60 years, to absorb up to 4 times the carbon released in the atmosphere as a result of its construction.

Carbon captured can be used as biomaterials in the production of roads, pavements and pipes for urban infrastructure development.

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Designs for a green skyscraper that could remove up to 1,000 tonnes of carbon from the atmosphere on an annual basis — the equivalent to growing 48,500 trees — was unveiled at the COP26 conference last week Pictured: a city of Urban Sequoias

Designs for a green skyscraper that could remove up to 1,000 tonnes of carbon from the atmosphere on an annual basis — the equivalent to growing 48,500 trees — was unveiled at the COP26 conference last week Pictured: a city of Urban Sequoias

Each high-rise would employ multiple approaches to sequester carbon , including construction with carbon-absorbing materials, growth of plants and algae (for fuel, energy and food), and direct air capture technology — as depicted

Each high-rise would employ multiple approaches to sequester carbon , including construction with carbon-absorbing materials, growth of plants and algae (for fuel, energy and food), and direct air capture technology — as depicted

‘We envision a future in which the first Urban Sequoia will inspire the architecture of an entire neighbourhood — feeding into the city ecosystem to capture and repurpose carbon to be used locally, with surplus distributed more widely,’ said Skidmore, Owings & Merrill’s senior associate principal Mina Hasman. The firm’s vision for a greener, cleaner city is reflected in the picture of modern-day Laos.

The carbon footprint of construction

According to Skidmore, Owings & Merrill, ‘the need to transform the built environment is clear.’

Construction presently accounts for nearly 40 per cent of all global carbon emissions — a figure that could easily rise in the future without alternative approaches.

In fact, experts have predicted that by 2060, an extra 230 billion square metres of building stock will be required in the world’s urban centres.

This is where Urban Sequoia comes in, allowing the built environment to turn buildings in to solutions, rather than problems, in the growing climate crisis. 

“This is the pathway to a sustainable future, which is possible today.” Imagine a world where a building helps to heal the planet,’ said Skidmore, Owings & Merrill partner, Kent Jackson.

“We designed our concept so it can be used and adapt to any city around the globe, with potential positive effects at every building scale.

‘The power of this idea is how achievable it is,’ agreed Skidmore, Owings & Merrill principal Yasemin Kologlu.

“Our proposal combines new design ideas and nature-based solutions with emerging and existing carbon absorption technology and integrates them into a way that is unique in the built environment.”

The prototype is designed to capture up to 1000 tons of carbon annually. However, it could be used to capture carbon from buildings of any size.

By constructing buildings from materials like bio-brick, biocrete, hempcrete and timber — all of which use less carbon than alternatives, and some of which continue to adsorb carbon over time — it is possible to reduce the carbon impact of construction by 50 per cent as compared to using concrete and steel.

The firm stated that a progressive approach to construction emission reductions could be reduced by 95%.

“We are rapidly evolving beyond the notion of carbon neutrality.” The time has passed to talk about neutrality,’ elaborated Skidmore, Owings & Merrill partner Chris Cooper.

‘Our proposal for Urban Sequoia — and ultimately entire ‘forests’ of Sequoias — makes buildings, and therefore our cities, part of the solution by designing them to sequester carbon, changing the course of climate change.’

The firm estimates that up to 120 tonnes of carbon can be stored per square kilometre (46 tonnes per square mile), if cities are reconstructed as dense carbon-absorbing environments and streets are retrofitted to capture additional carbon.

These strategies could also be applied to parks and green spaces, which they suggest, would almost triple the figure. 

Named for the world's tallest trees, the 'Urban Sequoia' design is the brainchild of the Chicago-based architectural firm Skidmore, Owings & Merrill and is based on technologies that are all available for use today. Depicted: an illustration of how the tower's design would allow it to take it carbon dioxide for storage or usage, while also producing products like biofuel

Named for the world’s tallest trees, the ‘Urban Sequoia’ design is the brainchild of the Chicago-based architectural firm Skidmore, Owings & Merrill and is based on technologies that are all available for use today. This illustration shows how the design of the tower would permit it to capture carbon dioxide and use it for storage, or even produce products such as biofuel.

The tower design's 'stack effect' would help draw in air to the centre of the building for processing a carbon extraction — while contributing to the building's net zero energy system. Pictured: an artist's impression of the 'Urban Sequoia'  concept

The tower design’s ‘stack effect’ would help draw in air to the centre of the building for processing a carbon extraction — while contributing to the building’s net zero energy system. Pictured: an artist’s impression of the ‘Urban Sequoia’  concept

'We are quickly evolving beyond the idea of being carbon neutral. The time has passed to talk about neutrality,' said Skidmore, Owings & Merrill partner Chris Cooper. 'Our proposal for Urban Sequoia — and ultimately entire "forests" of Sequoias — makes buildings, and therefore our cities, part of the solution by designing them to sequester carbon'

“We are rapidly evolving past the notion of carbon neutrality. The time has passed to talk about neutrality,’ said Skidmore, Owings & Merrill partner Chris Cooper. ‘Our proposal for Urban Sequoia — and ultimately entire ‘forests’ of Sequoias — makes buildings, and therefore our cities, part of the solution by designing them to sequester carbon’

‘If the Urban Sequoia became the baseline for new buildings, we could realign our industry to become the driving force in the fight against climate change,’ said Skidmore, Owings & Merrill’s senior associate principal Mina Hasman — a nod to how construction presently accounts for nearly 40 per cent of all global carbon emissions.

‘We envision a future in which the first Urban Sequoia will inspire the architecture of an entire neighbourhood — feeding into the city ecosystem to capture and repurpose carbon to be used locally, with surplus distributed more widely,’ Ms Hasman continued.

“If all cities around the globe built Urban Sequoias every year, it could reduce the atmospheric carbon by up to 1.6 Billion tons.

“With immediate attention and an investment in SOM’s prototype, this can be started now to build our first Urban Sequoia.

The Urban Sequoia concept was presented by Mr Jackson and Ms Hason in COP26’s Blue Zone on Thursday. 

While Skidmore, Owings & Merrill's prototype design is a skyscraper that can sequester up to 1,000 tons of carbon on an annual basis, the carbon capture approaches it uses might be applied to buildings of all types and sizes. Pictured: two architectural cross-sections of the high-rise design, showing how each floor integrates air capture and algae systems

While Skidmore, Owings & Merrill’s prototype design is a skyscraper that can sequester up to 1,000 tons of carbon on an annual basis, the carbon capture approaches it uses might be applied to buildings of all types and sizes. Two architectural sections of the high rise design are shown, which show how each floor incorporates both air capture and algal systems.

By constructing the buildings from materials like bio-brick, biocrete, hempcrete and timber — all of which use less carbon that conventional alternatives, and some of which continue to adsorb carbon over time — it is possible to reduce the carbon impact of construction by 50 per cent as compared to the use of concrete and steel. Pictured: two architectural cross-sections of the high-rise design, showing how each floor integrates air capture and algae systems

By constructing the buildings from materials like bio-brick, biocrete, hempcrete and timber — all of which use less carbon that conventional alternatives, and some of which continue to adsorb carbon over time — it is possible to reduce the carbon impact of construction by 50 per cent as compared to the use of concrete and steel. Here are two cross-sections showing the architecture of the high rise design. They show how each floor incorporates both air capture and algal systems.

CITIES CLEANERS USE “ARTIFICIAL” TREES

By keeping mosses in a container, such as those built by CityTrees, the conditions can be carefully controlled to ensure the plant is always thriving and therefore performing at optimum air filtration

CityTrees has made containers for mosses that can be controlled so they thrive and perform at their best.

CityTrees, also called artificial trees, use live plants and different kinds of mosses in order to remove toxins from the environment and produce clean and healthy air.

Even though they are a primitive form of life than many trees or flowers, the photosynthesis occurs in mosses. 

They can then absorb carbon dioxide, a greenhouse gas, from the atmosphere to make oxygen.  

Additionally, they can harbor friendly bacteria that traps pollutants. 

CityTrees has made containers for mosses that can be controlled so they thrive and perform at their best. 

Every CityTree is self-sustaining and includes a water tank and irrigation systems. There are sensors that monitor and control plant growth to ensure their health. It is powered using a mix of internal and on-board batteries. 

Each CityTree is a tree that has all the benefits of normal trees, except for the polluting effects.

Similar structures have previously been employed in other cities — including Berlin and Hong Kong — along with temporary trials across London. 

The plants can also absorb air pollution directly. Research has shown that PM2.5, or fine particulate matter in the air is the most harmful to human health. 

Because these particulates can penetrate your lungs or get into your bloodstream, they are extremely dangerous. 

Higher concentrations of particles are often found in urban areas along roads and main streets. 

One study from researchers at Beijing Forestry University in 2017 found ‘foliage acts as a bio-filter of air pollution and improves air quality due to the leaves’ rough texture and large contact area’. 

The problem with using regular trees or plants to remove pollutants and filter air is their dependence on the environment.

Their inability to thrive from disease, drought or vandalism will make it difficult for them to purify the air.   

Mosses, despite being a more primitive lifeform than most trees and flowers, conduct photosynthesis. This allows them to soak up carbon dioxide - a greenhouse gas - from the atmosphere and produce oxygen. Plants also directly soak up pollutants

Although they have a less advanced lifeform than flowers and trees, moses can still photosynthesis. They can absorb carbon dioxide, a greenhouse gas, from the atmosphere to make oxygen. Additionally, they absorb pollutants from the air.