[jurjenh]

Yes - you caught me out there :) but what I had in mind was a small-scale greenhouse - the kind you have in your garden, not the commercial-scale kind. But this brings back the restricted scale that we'd end up with if mass-produced long-distance transport bananas become non-viable.

What I mean with local IS growing plants suited for the climate. So in most cases, tropical is out, unless you can take advantage of specific areas that may have a generally warmer micro-climate to grow these foods. But this implies small scale, as otherwise you'd have to put in acres of greenhouses, at which point shipping may well be a better option.

The thing about our current system is that it is efficient, making long-distance shipping feasible. However, it is not resilient, as it depends on politics and cheap energy. I'm not sure if I'd class that as sustainable just because that's how we've done it for the last 50 or so years...

[ars]

But small scale is really really inefficient. I can't believe you recommend that as "sustainable" because it isn't. It relies on lots and lots of cheap land converted to farmland.

And just because you have lots of small greenhouses doesn't in anyway reduce the number of greenhouses - it just means you have to use more material to build them.

I can manage without tropical food, but do you think people in florida can manage without wheat?

Local is an ecological disaster. It's one of the ultimate forms of greenwashing because there is absolutely nothing "green" about it. They cut out a tiny bit of energy for shipping and replace it with just huge amounts of energy for everything else. Not to mention land and fertilizer.

> current system .... not sure if I'd class that as sustainable

It's more sustainable than any other alternative. The thing about our current system is that we use it because it's the best option we have.

It's very easy to prove that: Energy, fertilizer, land, etc cost money. Ergo the cheapest option is the one that uses the least of those. And the cheapest option is the one people naturally gravitate toward.

At best you can try to shift the costs, i.e. rather than spend energy, spend fertilizer; rather than pay for pesticides pay for spoiled food, etc. And if that is your goal then the current price structure may not match your ideal. (Since people optimize based on the current costs of those things, not your particular ideal cost for those things.)

This is basically what Organic food is: people believe that pesticides are too cheap, so they value them as more expensive and then the resulting food costs more.

But do not try to claim local is more efficient - because what input are you optimizing there? It's certainly not energy, land, pesticides or fertilizer.