The use of the word "green" here is just shorthand for "environmentally sensitive". This is not the same as "sustainable", which is a much broader concept incorporating social, economic and environmental concerns. Carbonsmart generally deals with these broader issues, but that seemed too much to try to address in these maps.
The idea is to highlight building projects and other human endeavours with a clear geographic component that demonstrate movement towards reduced environmental impact.
Let's see how green Africa is becoming.
A similar map has been created for San Francisco
, showing only solar pv systems.