This week I have been running a training course in an old venue wedged between two nesting grounds for tower cranes in central London. These leggy mechanical birds work all day to build their monumental, evergrey nests from concrete and steel.
These towering evergrey structures are the opposite of evergreen trees. Their growth emits — rather than absorbs — carbon dioxide. And their year round operation adds further carbon to the atmosphere.
But tower cranes don’t stay long in their evergrey nests. For once they are done building, the tower cranes take off and immediately start building new evergreys — sometimes demolishing perfectly good ones to build even taller ones.
Given their destructive nesting habits, it is not entirely clear how Tower Cranes will continue to flourish.