What you seek to do is increase the bulk albedo of the ground/surface/neighbourhood/city resulting in the net reflected solar radiation approaching the incoming

What you seek to do is increase the bulk albedo of the ground/surface/neighbourhood/city resulting in the net reflected solar radiation approaching the incoming leading to minimal absorbed shortwave and thus less compensating emitted longwave (sigma * T_surf*4). If you increase albedo, you're definitely going to lower the air temperature during the day. Rays are going to bounce around and eventually leave without warming anything. Other than your body if you haven't painted yourself white. However, with all these reflective surfaces you do get concerned with direct solar i.e. skiing in shorts & glare e.g. the "walkie-talkie" building [0]. [0] https://www.bbc.com/news/uk-england-london-23930675 https://www.bbc.com/news/uk-england-london-23930675