Andrew commented on Daniel's question: “Sorry but I think you are kidding yourself if you think we can ever efficiently vertically grow enough wheat, oats, canola etc. to meet our city demands. Fresh tomatoes and herbs maybe, but grain crops I think highly unlikely. And we're just starting to appreciate less intensive farming of animals, so let's not move towards vertical pig, sheep, cattle and chicken production. More intensive aquaculture I agree with. We just need to solve renewable energy transportation. I think the solution will lie in actually building a new kind of...”

Andrew commented on Zac 's question: “If you have ever lived on the land or in the bush, you quickly come to appreciate the role that nature plays in our existence and the duality of how small we are in relation to nature (eg. Floods) but equally how much damage we can do to it. So I think regional folk are generally more realistic and less naive about sustainability than city folk. But we am still talking in generalizations.”

Andrew asked the question: “Population density means that our cities will always be the great pollution factories of society regardless of how efficient we can make them. But our regional centres are the logical sites and custodians/managers for our carbon sinks. Surely we should focus on making this a viable relationship between country and city and the carbon tax/emissions trading scheme should be focused to help to cement this relationship and provide opportunities for more sustainable cities and regions. Yes?”