Why We Should Build Wooden Skyscrapers

I have another TED talk I came across a few years ago which I'd like to share with you. It's a talk by Michael Green in 2013. He talks about the importance of building our cities with timber. He believes that wood is the material we need to give priority to. The full talk can be watched below or on TED website.

Michael Green: Why we should build wooden skyscrapers

Cities are built using two main materials: steel and concrete. They're great and durable materials but they're also materials with very high embodied energy and embodied carbon. Steel and concrete are responsible to 8% of the global GHG emission.

Wood is the only material that grows by the power of the sun. As the trees grow, they produce Oxygen and absorb carbon dioxide. Once the trees die, it will give back that carbon dioxide into the air (if it's burned) or into the ground (if it's decayed). That's why using wood as building materials or for furniture is a great way of storing the carbon dioxide. The use of a cubic meter of wood is equal with storing a tonne of carbon dioxide. Obviously, our strategy to mitigate climate change is to reduce emission and to store the carbon not to go back to the atmosphere. Wood has both capacities. Through the help of technology, wood can be engineered so that it can be used to build skyscrapers to meet the demand of the current cities.

Fire is one of the most commonly questioned problems against the idea of wooden skyscrapers. Green argues that the fire in wood is highly predictable and we can use fire science to make the building fire-safe. The next big question is deforestation, which can be solved by sustainable forestry model. Green continues with a comparison of amount of emission of a 20-storey building is made of concrete and wood. If it's made of concrete, it will emit 1,215 tonnes of CO2, while it's built out of wood, it will actually store 3,150 tonnes of CO2. That's a 4,360 net difference of carbon emission.

An example of a built wooden high rise is the Forte building in Melbourne, which is regarded as the tallest timber residential building in the world. Green believes that it's the time for the "Eiffel Tower Moment" for wood skyscrapers: the beginning of a leap or a new era in the use of wood as a building material at the much larger scale.