One particular quirk of the team’s chosen method for calculating a Green View Index for an area is that it is (as they acknowledge) limited by where Google Street View vehicles can access.
This leads to the interesting side-effect switzerland rcs data that their Treepedia map of the Manhattan part of New York has a large dark space where Central Park is. That said, this approach does highlight the amount (or lack thereof) of trees on town and city streets, which in itself is an opener for discussion.
Treepedia map of Manhattan, New York showing the 'empty' space of Central Park
While Treepedia covers a limited number of international cities currently, the team are keen to share their code and have released an open-source Python library that can be used to compute the Green Value Index for any city or region. You will need a GIS file for the street network of your chosen area and a Google StreetView API key.
Have you tried mapping how green your area is? Let us know in the comments below.