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.
Scroll down to see the video

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
‘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.
“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. 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

“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. 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. 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.