Building sustainable cities with wooden skyscrapers

MORE THANUN half the world’s population dwell in cities, and by 2050 the expects that proportion to reach 68%. This means more homes, roads and other infrastructure. In India alone, the equivalent of a city the size of Chicago will have to be developed every year to meet demand for housing. Such a construction boom does, though, bode ill for tackling climate change, because making steel and concrete, two of the most common building materials, generates around 8% of the world’s anthropogenic carbon-dioxide emissions. If cities are to expand and become greener at the same time, they will have to be made from something else.As it happens, Chicago might become part of the answer. In recent years, as architects have become increasingly interested in modern timber-construction methods, wooden buildings have been getting steadily taller. The current record is held by the 85-metre-tall Mjostarnet building in Norway (see picture), completed in 2019. But this would be dwarfed by the River Beech Tower, a 228-metre edifice proposed for a site beside the Chicago river.