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Super timber, vertical forests and vertical farming: Geneva celebrations show the sky is the limit for forests’ contribution to sustainable cities

Green spaces in cities, including parks, gardens/vertical gardens or urban farms are emerging as key solutions to tackle urban sustainability challenges. Trees in cities serve as natural air conditioners, cooling the air by between two and eight degrees Celsius, whilst urban forests filter harmful pollutants from the air and act as carbon sinks to help mitigate climate change. Urban farms contribute to urban food security by providing fresh local produce, reducing food miles and reconnecting people to the food they eat.

Vertical forests, vertical farming and vertical high-rise wood constructions: the denser our cities become, the greater the need to address the lack of space available for plants and trees, and to identify innovative ways of integrating natural systems into our urban spaces – where the sky is the only limit.

International Day of Forests is a global celebration of forests. This year’s theme highlights the key role played by forests in creating sustainable cities.

To celebrate this occasion, UNECE and FAO gathered eminent speakers at the Palais des Nations in Geneva to showcase new approaches to urban farming, the integration of trees in buildings, wood construction and architecture.

“Forests provide the solution to many of the sustainability problems that we will face in an urbanized world”, highlighted Ms. Olga Algayerova, Executive Secretary of UNECE.

The exchanges demonstrated that technology and ingenuity have no limits when creating sustainable and green cities.

H.E. Ambassador Foo Kok Jwee, Permanent Representative of Singapore to the UN in Geneva, emphasised the importance of vertical farming as it “optimises land use in land-scarce Singapore and can operate on minimal manpower”.

Arch. Maria Chiara Pastore of Stefano Boeri Architetti, famous for creating the vertical forests model for sustainable residential buildings embodied by Milan’s Bosco Verticale (Vertical Forest), emphasized how its vegetal system contributes to the construction of a microclimate, produces humidity, absorbs CO2 and dust particles and produces oxygen.

This is not only instrumental in curbing climate change but also utilises accessible building materials for large-scale construction projects. Compared to concrete, steel, cement and glass, wood requires less energy to produce and stores – rather than emits - carbon.

Dr Michael Ramage, Director of the Centre for Natural Material Innovation at the University of Cambridge, instrumental in the design of the “The Toothpick” (a wooden skyscraper set to become the second tallest building in London), discussed “super-tall timber”. He explained how wood construction involves cross-laminated timber, a material made of many sheets of wood glued and compressed together, is stronger than steel and a viable candidate for building skyscrapers.

One large tree can also absorb 150kg of carbon dioxide a year and thereby act as a carbon sink to help mitigate climate change and lower cities’ carbon footprint. With 1.9 billion hectares, corresponding to more than 40 per cent of the total global forest area, the UNECE region has more forests than any other region of the world. With growing urbanisation, forests are instrumental; and when it comes to creating sustainable cities - technology and ingenuity have no limits.

For pictures of the event, please see:

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