This algorithm has found the greenest city in the world 2

Forget counting parks – a database of urban greenery ranks cities based on how leafy they look to residents.

To create the greenery maps, Ghaeli’s team feed images from Google Street View into an algorithm that estimates what percentage of each image consists of trees. Plotting these scores on a map determines the leafiness of street.

The results can be combined to give each a Green View Index (GVI) – Ghaeli’s rating of how leafy each city is on a street level. Singapore tops the table with a GVI of 29.3 per cent with Sydney and Vancouver close behind. At the greyer end of the scale, Paris scores a paltry 8.8 per cent.