Would roof gardens be a practical way to help the environment? Having areas of greenery on the tops of flats and large

Question: Would roof gardens be a practical way to help the environment? Having areas of greenery on the tops of flats and large buildings in cities where there’s minimal space on the ground for gardens? Only occasionally you see grass and plants on the tops of houses, so should they be used more around polluted places? Would they help?
- Keywords:
  buildings,
  flats,
  garden,
  greenery,
  houses,
  plants
Asked by anon-177638 to Daniel, Andrew on 18 Jun 2018.
- Daniel Marsh answered on 18 Jun 2018:
  
  Lots of tall buildings in cities already have roof gardens, these sit above the worst of the pollution and make good use of space when there isn’t much available. As to whether they actually benefit the air would depend on their size and the type of plants used but generally speaking the combined surface area of plants against the volume of the air to be treated would be so small that they wouldn’t really have any impact at all…. they still look nice though!