London, Lisbon, Milan, Bordeaux, Burgas and Warsaw have triggered the investment as part of the major international smart cities programme, Sharing Cities.
The Bloomberg Philanthropies initiative aims to help the cities deliver "high impact" digital services and share lessons learned with the rest of the world.
Austin, Athens, Lisbon and Venice are the latest major cities to have ‘peaked’ their greenhouse gas emissions, meaning they won’t rise any further and are now falling.
