Well, if the tree "technically" belongs to the city, it's their
problem. You could enlist your neighbors to petition the city to
remove the offending tree and replace it with something less
offensive. (Hell, hang a sign on the tree saying, "ask the city
council to replace this tree with something that doesn't stink.
Inquire within.")

I bet if that's the case then a nicely gift wrapped package of gingko
'apples' to some city officials will get fast results. Or will get your
face plastered on the news, depending what things are like in NYC these
days.

-- Salty