I don’t consider myself to be in bad shape, but climbing a few flights of stairs sure takes the wind out of me. Anything more than, say, four, I opt for the elevator. And you know what? I feel ok about this.
I should say that I believe the world is becoming warmer, and an increase in the amount of carbon in the atmosphere is to blame. I’ve seen An Inconvenient Truth. I get it. We humans are doing some bad stuff that we need to stop doing.
But some insist this includes riding the lift. A recent “green campus” initiative at my university encouraged people to take the stairs (I work on the 14th floor). The current most-emailed Times article (The Year Without Toilet Paper) applauds an environmentally saintly couple who have stopped taking the elevator, at home and at work. The logic is this: Elevators require energy, and most of our energy comes from sources, such as the burning of coal, that release carbon; therefore, we should avoid using elevators.
Perhaps because I’m a skinny-legged, self-interested, lazy guy, I feel that this argument is missing something. Specifically, what I’d need to see before committing myself to a Sisyphean life of stair climbing is a comparison showing that elevators require more energy and carbon than a typical human to move the same distance. I am skeptical.
The human body, like an elevator, is a machine requiring energy to perform work. We’re not magic; there’s no free lunch here. Converting glucose into the energy needed to climb a set of stairs produces carbon dioxide, which we exhale. More important, we get this glucose by consuming food that, in a typical American diet, requires a great amount of fossil fuel to grow, raise, and ship. Those of us who eat a lot of meat only compound the problem by bringing into existence other energy-hogging, carbon-polluting animals. I could try to estimate just how much energy and carbon is ultimately needed for the average human to climb a flight of stairs, but the very fact that this calculation hasn’t been provided by those who’d like us to forgo elevators makes my point: we’ve been given no evidence that taking the stairs is any better.
Elevators are good at their job, efficiently designed to move people up or down in a straight line. Moreover, given the fixed mass and inertia of an elevator, each additional individual and floor adds only marginally to its energy requirement. So while it may be wasteful for a single able-bodied person to ride an elevator up one floor, it seems almost silly for 10 people wishing to travel 14 not to.
I’m happy to turn down the thermostat at night, have my computer go to sleep whenever I look away, and even unplug appliances when they are not in use. But for now, I’ll be taking the elevator up to my office. It’s a better climber than I – I just know it.
Friday, March 23, 2007
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4 comments:
What a fascinating post, jbert. I would be interested in seeing some equations of the relative energy use with escalators (my personal favorite) as well. Without knowing any facts whatsoever, I argue your post is, although interesting, probably wrong. I imagine that, as efficient as we can design elevators, that can't compare to the human body and 16.5 million years of evolution. Any efficiency because of the small relative change in inertia of the elevator will be offset by all of the times the elevator travels inefficiently with a small cargo, or travels between floors empty. A human walking up stairs is always moving most efficiently, unless that person weighs as much as an elevator, but those people are usually bed bound. But don't fret, it's probably more green to stop eating meat or driving a car than to stop riding the elevator anyways.
Speaking of efficiency, we might also consider changes in relative efficiency over time. Let's say you start taking those stairs to and from your office every day. Sure, at the onset of your new efforts, you'll be huffing and puffing away when you make it to the top. But over time, you'll get stronger and more fit, making your body even more energy efficient. That elevator - as sediments build up, oiled gears dry out, and finely tuned mechanisms wear out - gets less energey efficient with each and every trip it takes.
At an incredibly basic level, when you take the stairs, you have to do enough work to move (say) 165 pounds of flesh and bone up a certain distance. If you take the elevator, you have to move the same weight, PLUS the weight of the elevator. Even if the elevator is designed perfectly efficiently (counterweights and all that), it still does have to be accelerated and decelerated, and even with energy recaptured by a flywheel and dynamo system, there are losses in that.
And an elevator weighs a hell of a lot more than a person.
So unless your entire dinner has been flown from another continent (and remember that these people are pledging to eat local -- I myself participate in a community supported agriculture program, which for a few hundred dollars gets me more local produce than I can eat, for nine months out of the year), it is absolutely absurd to think that taking the elevator will use less energy than taking the stairs.
Jbert, I think you hit a particular nail on the head, whatever the merits of lift riding. Is the goal to have the least calculable impact on the earth? In and of itself, that's a dead end to me; you'll always fall short, as each choice will branch into its own range of optimal use. The more unplugging you do, the more of an imperial kind of exercise this seems. Eventually it hits you that it's higher-yield to evangelize than be that little bit more efficient, and that can be a drag. So you scale it back to its own right level. With another thing upon another, you have to account for the impact of your doing all this contingency planning versus spending your time in more low-impact ways. Throw in the effect on happiness of all this maximizing, and Swarthmore psychology professor Barry Schwartz will tell you you've yet another think coming.
Looking back at the story on this couple's example, I think it's the language of "no impact" that brings on the danger of thinking in terms of optimization; getting all your ducks in a row is very hard to do with human ducks. Besides, impact is not some value that just speaks for itself; it's the product of some other commitments that are more interesting and important, if less gimmickally packagable. Rather, something like "conscious consumer" connotes that our habits--all of them--are chosen and can change. This example invites its own high horse problems, but it's in a direction that I think would reach a wider audience than the image of sanitizing your butt in a different way. Too much, too soon.
Think, rather, of the NYT Magazine article, "Unhappy Meals", from January 28th:
"Eat foods. Not too much. Mostly plants."
Now that's a much better campus poster, don't you think?
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