Water

On a first glance, it seems a good idea to grow our own food because agriculture is green.

But no. The reality is quite different.

First, agriculture is, by and large, not environment friendly. To most countries (Hong Kong included), growing our own food does not mean we turn part of the cement forest to genuine ones; it is achieved by converting some woods and grasslands of the country side into farms and fields. The place for wild trees and flowers becomes occupied by edible crops and vegetables.

You may argue producing our food locally is still a good idea because we consume less petroleum (and hence there is less air pollution) for the transportation of crops.

Well, do you know what is water footprint?