They did some work around the question of the value that a tree planted in a city provides. It was quite interesting, because it was in the order of maybe $80 a tree per year. Then they looked at the cost of actually planting the tree, and maintaining the tree and whatnot, and it was in the order of $10 or $20.
There is a real net benefit to having a tree in a city. The benefit it provides is in helping to clean the air, to provide shade, to help manage local climates.
The City of Toronto has put in place a couple of interesting requirements. One is that for all new buildings that are over a certain size—I can't tell you what that is, but it's reasonably large—there's a requirement to use green roofs. It's to help regulate the local temperature, provide some habitat for some species, and so on.
I think the people who are living in those buildings are receiving a clear benefit from it as well, such as lowered cooling costs, for sure, in the summer. As well, quite often you can access these roof gardens. I don't know if you'd call it a recreational benefit or just a well-being benefit for the dwellers who are in an urban environment with perhaps less green space. We know that green space is an environment that oftentimes encourages a feeling of well-being, and this provides access for the people who live in an area that doesn't give them as much ready access to it.
Those are a couple of areas of real cost savings. The more green space you have, the more chance you have for some improvements to air quality. There has been a fair bit of work done around that as well. If you have better air quality, of course you have fewer respiratory diseases and impacts on people, so it reduces health care costs.
I could see real benefits to incorporating the notion of conservation into urban planning. It's not the only thing you have to consider. There are many other things to consider, because running a city is a complex business. However, there is certainly benefit to the dwellers of cities to have conservation built into the city design.