How green are country’s ‘green islands’ in reality?

Following Halki and Astypalaia, Poros is now poised to become Greece's third "green island" under the GR-Eco Islands initiative. 

But, in practice, how green are the country's "green islands"? The project is currently focused on energy and less polluting transportation, but it doesn't address waste, sewage, or water "production."

The project appears to be functioning effectively in terms of communication, substantially boosting the number of visitors to the islands, a trend that doesn't really work in favor of the small islands' sustainability.

GR-Eco Islands focuses on decarbonizing the electricity production of small islands and implementing key infrastructure projects. The first two were Astypalaia (in partnership with Volkswagen) and Halki (with Citroen and other companies). 

On Astypalaia, which is not connected to the mainland electricity system,...