At the TED Conference 2013, architect Michael Green argues that wood architecture is better than steel and concrete when it comes to protecting the environment. Tall buildings are made of steel and concrete and the greenhouse gas emission of these materials is huge (three percent of the world’s energy goes into making steel, and 5 percent goes into making concrete). Green notes that most people think transportation is the main cause of CO2 emissions, but actually it is building — accounting for 47 percent of CO2 emissions.
Current building codes only allow wood buildings to be four stories high, and Green wants to change this. He proposes we use wood architecture and build skyscrapers out of wood. Trees store carbon dioxide, and by building with it, says Green, we could sequester the carbon. Building with one cubic meter of wood, he claims, stores one ton of CO2.
He is not proposing to build huge towers with small two-by-four pieces of wood. In his speech, he explains the technology that has been created to form rapid growth trees into massive lumber panels and the flexible system technology that assists in building with these huge pieces of wood.
An obvious question that people ask about his system is deforestation. To this, he insists there are sustainable forestry practices, and says that enough wood is grown in North America every 13 minutes for a 20-story building.
– Mary Purcell