Tall-building boosters, expecting 7.3 billion people to be living in cities by 2050, are struggling to make urban skyscrapers more sustainable. They agree that the road to true greening is not an easy one.
"We will likely get there in 50 or 60 years," predicted Timothy Johnson, chairman of the Council on Tall Buildings & Urban Habitat, at CTBUH 2012, held on Sept. 19-21 in Shanghai.