I've just been sent an amazing article on how Madrid is using a radical new type of green wall planting system to combat their arid heat and pollution: http://www.npr.org/sections/parallels/2017/07/09/495905421/hot-dry-...

Surely this ingenious technique could also be used here on the walls of high-rise developments, to lessen the harsh impact of the concrete curtain walls which make these so environmentally unfriendly. That would help to redress the balance between hard and soft landscaping which is so badly upset by high-rise development being concentrated into small sites in a formerly low-level urban environment. Not only back lots but gardens are increasingly being built over and even parts of public parks are increasingly threatened with redevelopment.

Current 'green wall' techniques here are much less well integrated with the buildings than this clever system, which also insulates against extremes of temperature.

Can more be done to spread this kind of thinking, with a view to improving the environmental impact not only of new projects but by retrofitting existing developments?