I came across some interesting material on various topics including packaging (did you know paper bags are several times worse from a carbon-footprint perspective than oil-based plastic bags in food packaging?) and local vs road-hauled food.

One of the key issues is that:

the debate on environmental issues is moving fast but is too often guided by the need to gain marketing advantage rather than deliver genuine benefit. As a result too much effort, in both business and government, is put into doing what customers and voters expect and not enough into rigorously researched long term solutions.

Fascinating re: tomatoes... if you just ate these in season you'd only have them in August and September.