What does a sustainable city look like?

Since I'm still out of the country and missing what I'm sure are some fun tutes for urban sustainability, I'm going to go ahead and do some thinking out loud on the topic from afar.

The second question of the week got my attention:

Do you think urban living is intrinsically ‘unhealthy’ or ‘unnatural’ for human beings?

My first response: I really hope not. I love cities. I love being near other people, being able to come together to create things of beauty and/or purpose. Cities are where humans get creative and do great things. They're where minorities can be majorities in some small space, and where we support each other. The history of urbanization is also the history of technology, education, civil society and government.

Aside from all the nice stuff, we need cities if we're all going to fit on this globe. If everyone moved to the country, the country wouldn't exist anymore. There are around 3 billion more people coming onto this planet in the near future, and they'll mostly live in cities.

Problem is, the connection between urbanisation and increased life quality feeds right into the fact that when people move to the city, the consume more. More meat, more energy, more fuel, more stuff in general.

We know that as a society, we collectively need to consume less stuff and start living in ways that don't degrade the earth systems we all depend on. Half of us live in cities, soon to be 70% (by 2050). We consume more than our share and we can take the lead in reducing. That means taking every efficiency opportunity that comes along, particularly with infrastructure, travel, and all the basic services that keep a city going. Beyond that it gets a bit trickier - there's the problem of shaping cities that are by nature efficient, and what that looks like. In the Australian context, I think density is the biggest fight. We all want our backyards and wide streets. Why are we so afraid of apartments? Can we get away with staying in big houses? (I have a funny feeling we can't, but feel free to prove me wrong)

And what about the stuff we bring into the houses? It's a lot easier to control the emissions and resource use that we see domestically, leading us to focus on water, electricity and so on. But every time I walk into a mall I can't help but think about the impact of all the stuff we buy. Clothes, furniture, electronics - it's all being made somewhere, in most cases not very efficiently and with terrible social and environmental impacts. In the ideal world where life cycle analysis is possible for everything ever (can someone make a smartphone app please?), we'd be able to add the carbon impact of production not to the country making this stuff, but the country consuming it. As long as the USA, Australia and friends keep buying stuff made in China by burning huge amounts of coal, you can bet they're going to keep doing it.

Moving on to the issue of planners vs architects vs graffiti artists etc in creating a city. The city is a collaborative space, and the experience of Canberra makes me a bit cautious of entrusting it to planners and government alone. So many of my favorite urban spaces are a bit of an accident. I feel like Melbourne's character comes from its more ridiculous 5 way intersections and strange little shopping areas that weren't really supposed to be there. Of course both Canberra and Melbourne are far from being 'sustainable cities', and the challenge of retrofitting an established landscape is huge. Is it possible to do some kind of passive design? Set the boundaries for what resources will be available where, and let people have a say in how a space actually looks? For example, if you're trying to improve a suburb, commit to a transport spine and some parks, and let the residents work out where the shops should go?

I really don't know. But I do stick by my gut feeling - cities are a collection of people, and like any collection of people, they can be awful or amazing. We have to have some big conversations to decide which.