The mayor can to some extent reduce the damage and injury
that the city sponsors against the global ecology and peoples,
but the idea that he can make New York sustainable is sheer hubris,
or maybe it's sheer ignorance of what sustainable means?

So first, where are 8 million peoples' food supplies coming from, and what are their production impacts ?

Second, ditto for their energy and for their purchases' production energy.

Etc.

Regards,

Backstop

So first, where are 8 million peoples' food supplies coming from, and what are their production impacts ?

Second, ditto for their energy and for their purchases' production energy.

I don't mean to be flip on this, but I don't have time to give a lengthy description of how dense cities allow large populations to live efficiently and not take up so much space as suburban living. So at the risk of giving too short an answer to your questions, my response is: All the land that they don't use

1. Capable of being sustained.
2. Capable of being continued with minimal long-term effect on the environment: sustainable agriculture.

They didn't say self sufficient. The very idea of civilization involves interdependent networks achieving a sufficient quality of life through specialization and trade. Urban areas trade their products to rural areas for food grown in the rural areas. No city is going to be able to grow their own food at the densities present in New York. Ever. This is not a bad thing. And I don't think those who wrote this plan would suggest otherwise.