Alex Steffen 談城市塑造可共享的未來

以下為系統擷取之英文原文

Climate change is already a heavy topic, and it's getting heavier, because we're understanding that we need to do more than we are. We're understanding, in fact, that those of us who live in the developed world need to be really pushing towards eliminating our emissions. That's, to put it mildly, not what's on the table now. And it tends to feel a little overwhelming when we look at what is there in reality today and the magnitude of the problem that we face. And when we have overwhelming problems in front of us, we tend to seek simple answers. And I think this is what we've done with climate change. We look at where the emissions are coming from -- they're coming out of our tailpipes and smokestacks and so forth, and we say, okay, well the problem is that they're coming out of fossil fuels that we're burning, so therefore, the answer must be to replace those fossil fuels with clean sources of energy. And while, of course, we do need clean energy, I would put to you that it's possible that by looking at climate change as a clean energy generation problem, we're in fact setting ourselves up not to solve it.
And the reason why is that we live on a planet that is rapidly urbanizing. That shouldn't be news to any of us. However, it's hard sometimes to remember the extent of that urbanization. By mid-century, we're going to have about eight billion -- perhaps more -- people living in cities or within a day's travel of one. We will be an overwhelmingly urban species. In order to provide the kind of energy that it would take for eight billion people living in cities that are even somewhat like the cities that those of us in the global North live in today, we would have to generate an absolutely astonishing amount of energy. It may be possible that we are not even able to build that much clean energy. So if we're seriously talking about tackling climate change on an urbanizing planet, we need to look somewhere else for the solution.
The solution, in fact, may be closer to hand than we think. Because all of those cities we're building are opportunities. Every city determines to a very large extent the amount of energy used by its inhabitants. We tend to think of energy use as a behavioral thing -- I choose to turn this light switch on -- but really, enormous amounts of our energy use are predestined by the kinds of communities and cities that we live in. I won't show you very many graphs today, but if I can just focus on this one for a moment, it really tells us a lot of what we need to know -- which is, quite simply, that if you look, for example, at transportation, a major category of climate emissions, there is a direct relationship between how dense a city is and the amount of climate emissions that its residents spew out into the air. And the correlation, of course, is that denser places tend to have lower emissions -- which really isn't all that difficult to figure out, if you think about it.

Basically, we substitute in our lives access to the things we want. We go out there and we hop in our cars and we drive from place to place. And we're basically using mobility to get the access we need. But when we live in a denser community, suddenly what we find, of course, is that the things we need are close by. And since the most sustainable trip is the one that you never had to make in the first place, suddenly our lives become instantly more sustainable. And it is possible, of course, to increase the density of the communities around us.
Some places are doing this with new eco districts, developing whole new sustainable neighborhoods, which is nice work if you can get it. But most of the time, what we're talking about is, in fact, reweaving the urban fabric that we already have. So we're talking about things like infill development: really sharp little changes to where we have buildings, where we're developing. Urban retrofitting: creating different sorts of spaces and uses out of places that are already there. Increasingly, we're realizing that we don't even need to densify and entire city. What we need instead is an average density that rises to a level where we don't drive as much and so on. And that can be done by raising the density in very specific spots a whole lot. So you can think of it as tent poles that actually raise the density of the entire city.
And we find that when we do that, we can, in fact, have a few places that are really hyper-dense within a wider fabric of places that are perhaps a little more comfortable and achieve the same results. Now we may find that there are places that are really, really dense and still hold onto their cars, but the reality is that, by and large, what we see when we get a lot of people together with the right conditions is a threshold effect, where people simply stop driving as much, and increasingly, more and more people, if they're surrounded by places that make them feel at home, give up their cars altogether. And this is a huge, huge energy savings. Because what comes out of our tailpipe is really just the beginning of the story with climate emissions from cars. We have the manufacture of the car, the disposal of the car, all of the parking and freeways and so on. When you can get rid of all of those because somebody doesn't use any of them really, you find that you can actually cut transportation emissions as much as 90 percent.
And people are embracing this. All around the world, we're seeing more and more people embrace this walkshed life. People are saying that it's moving from the idea of the dream home to the dream neighborhood. And when you layer that over with the kind of ubiquitous communications that we're starting to see, what you find is, in fact, even more access suffused into spaces. Some of it's transportation access. This is a Mapnificent map that show me, in this case, how far I can get from my home in 30 minutes using public transportation. Some of it is about walking. It's not all perfect yet. This is Google Walking Maps. I asked how to do the greater Ridgeway, and it told me to go via Guernsey. It did tell me that this route maybe missing sidewalks or pedestrian paths though. (Laughter) But the technologies are getting better, and we're starting to really kind of crowd source this navigation. And as we just heard earlier, of course, we're also learning how to put information on dumb objects. Things that don't have any wiring in them at all, we're learning how to include in these systems of notation and navigation.

Part of what we're finding with this is that what we thought was the major point of manufacturing and consumption, which is to get a bunch of stuff, is not, in fact, how we live best in dense environments. What we're finding is that what we want is access to the capacities of things. My favorite example is a drill. Who here owns a drill, a home power drill? Okay. I do too. The average home power drill is used somewhere between six and 20 minutes in its entire lifetime depending on who you ask. And so what we do is we buy these drills that have a potential capacity of thousands of hours of drill time, use them once or twice to put a hole in the wall and let them sit. Our cities, I would put to you, are stockpiles of these surplus capacities. And while we could try and figure out new ways to use those capacities -- such as cooking or making ice sculptures or even a mafia hit -- what we probably will find is that, in fact, turning those products into services that we have access to when we want them, is a far smarter way to go.
And in fact, even space itself is turning into a service. We're finding that people can share the same spaces, do stuff with vacant space. Buildings are becoming bundles of services. So we have new designs that are helping us take mechanical things that we used to spend energy on -- like heating, cooling etc. -- and turn them into things that we avoid spending energy on. So we light our buildings with daylight. We cool them with breezes. We heat them with sunshine. In fact, when we use all these things, what we've found is that, in some cases, energy use in a building can drop as much as 90 percent. Which brings on another threshold effect I call furnace dumping. Which is, quite simply, if you have a building that doesn't need to be heated with a furnace, you save a whole bunch of money up front. These things actually become cheaper to build than the alternatives.
Now when we look at being able to slash our product use, slash our transportation use, slash our building energy use, all of that is great, but it still leaves something behind. And if we're going to really, truly become sustainable cities, we need to think a little differently. This is one way to do it. This is Vancouver's propaganda about how green a city they are. And certainly lots of people have taken to heart this idea that a sustainable city is covered in greenery. So we have visions like this. We have visions like this. We have visions like this.

Now all of these are fine projects, but they really have missed an essential point, which is it's not about the leaves above, it's about the systems below. Do they, for instance, capture rainwater so that we can reduce water use? Water is energy intensive. Do they perhaps include green infrastructure, so that we can take runoff and water that's going out of our houses and clean it and filter it and grow urban street trees? Do they connect us back to the ecosystems around us by, for example, connecting us to rivers and allow for restoration? Do they allow for pollination, pollinator pathways that bees and butterflies and such can come back into our cities? Do they even take the very waste matter that we have from food and fiber and so forth, and turn it back into soil and sequester carbon -- take carbon out of the air in the process of using our cities?
I would submit to you that all of these things are not only possible, they're being done right now, and that it's a darn good thing. Because right now, our economy by and large operates as Paul Hawken said, "by stealing the future, selling it in the present and call it GDP." And if we have another eight billion or seven billion, or six billion, even, people, living on a planet where their cities also steal the future, we're going to run out of future really fast. But if we think differently, I think that, in fact, we can have cities that are not only zero emissions, but have unlimited possibilities as well.
Thank you very much.
(Applause)

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