It's true that only about 1 part in 125 of New Zealand's land area is covered over in sprawl, with much less than that being actually built on (much of the sprawl area is garden, grass and trees). Because of this, we argue that urban sprawl is not an environmental problem as it consumes such little land in the greater scheme of things. Indeed, our agrarian actions are many times more invasive.
But there's another way of looking at it.
Take this scenario. We discover 100 exo-planets close by in our galaxy that are full of life. Would that then make it okay for us to completely trash our earth, because earth is then only 1% of the life-bound planets that we specifically know of? Obviously not. The existence of other life planets, no matter how many there might be out there, in no way devalues the earth that we currently stand on. Intrinsic value is not a relativity game.
With this appreciation, we can understand the grief many might feel with the mental picture of 'mother nature' being concreted over for human settlements. Even though people may know that it's only a very small portion of the total land.
You can still argue that no matter how big our planet is overall, sprawl nonetheless paves over a lot of earth and that can reasonably be seen as a problem.
So let's take this common grief - and look at the reactions.
The reaction promoted by mainstream environmentalists is to stop sprawl outright. Forcing cities to go up - not out.
The problem, as most now know, is that stopping sprawl comes with significant costs. Anti-sprawl policy compromises economic development and housing affordability as it artificially enforces scarcity with land to build on, and it aggravates many other problems that come with crowded living, such as pollution and mental health problems.
Yet mainstream environmentalists hold to anti-sprawl policy, because for them the green grass should nonetheless be preserved, even at very real human costs.
But there is another defensive potential to stop humans from concreting over the earth, again presuming that 1 part in 125 is to be seen as already too much. The idea is to design sprawl so that it doesn't need concrete (or very little of it) in the first place.
Is sprawl without concrete realistic?
Take a look at the diagram directly below. It shows us how much land we need to pave over for a functional road, for if we want to make a religion out of keeping the green instead of the grey.
You can already buy driverless pod cars, off the shelf, that can operate on little more than a couple of concrete rails like what the image below indicates. So we can get rid of most roading for new residential developments, if that is what we really want.
And take a look at the next image to get my point. We can virtually bury houses in the greenery if we insist, especially if we move in the direction of earth-houses.
Human settlement can in fact be remarkably uninvasive, and indeed it can drive ecologically-rich garden-style development. In fact there are odd spots of this kind of development everywhere. It's beautiful, and green, and potentially very affordable.
So where do the mainstream environmentalists stand with this kind of development, as an alternative possibility to Urban Growth Boundaries? That is, the idea of greening sprawl rather than outright blocking it?
The answer, sadly, is nowhere to be heard. I have promoted this possibility in forums to environmentalists in the past, and all I seem to get is a stone-cold silence to the suggestion. It's almost like they're more interested in beating-up on humans than helping out the environment!... Or, more realistically, conforming to a party-line so as to maintain their unity and preserving their backing.
It's tragic. We can so easily improve sprawl today if we really can't stand all that concrete. We have the tools to do it. There is no need, by any reasonable measure, to block human expansion. We can simply regulate sprawl to be pretty much as green as we want, if we want.
But alas, this possibility never seems to enter the public conversation on 'up versus out'. I hope this will one day change, because we're paying dearly for our current anti-sprawl policy (Urban Growth Boundaries), and most notably with a housing market where prices have gone mad. And all of it is totally unnecessary.
Extended article: http://andrewatkin.blogspot.co.nz/2011/12/green-sprawl-why-not.html