HARDtalk - Sir Terry Farrell

In Dubai developers are building a tower more than a kilometre high. China's cities are expected to generate tens of thousands of new skyscrapers over the next twenty years. Is the inexorable spread of concrete and steel being designed and built in a sustainable way? Sir Terry Farrell is one of the world's leading architects with a portfolio of landmark buildings from London to Beijing. Stephen Sackur asks him if architects and planners are putting our planet in peril.