A few nights ago, as I fumbled for my keys outside my entryway door, a receipt fluttered from my bag onto the wet path. I didn’t want to pick it up. I was cold, my clothing had been thinned and chilled by the wind and my fingers were numb. I didn’t feel like bending down to pick up my trash and throw it out. But I did it anyway.

I am fastidiously opposed to littering. Not because I am compulsively tidy, but because everybody has an obligation to help keep the environment clean. I use the word environment to mean both our immediate surroundings and the interdependent systems of planet Earth (Environment with a capital “E,” you might say). As a poster in my kindergarten classroom read, “No job is too big, no action too small, for the care of the Earth is the task of us all.”

Everybody knows that littering challenges our civic cleaning and drainage systems and threatens the livelihood of plants and animals with foreign and, perhaps, toxic substances. We cluck at the sight of cigarette butts and old newspapers on the sidewalk. We quiver with rage when a driver ahead of us on the road throws a Styrofoam cup into the breeze. Trash belongs in the facilities that public and private institutions amply provide, not strewn about our shared living and working spaces.

I have tried to come up with an example of a situation in which littering would not be reprehensible. Barring something life-threatening and convoluted, there exists no such situation. I remember waking up on a lovely Sunday morning early in my freshman year to see Old Campus covered in beer cans, plastic cups, cigarette butts and scraps of uneaten food; my first reaction — “How disgusting! How very rude!” — was followed closely by an excuse to which I have by now grown all too accustomed — “Ah, but they were drunk.”

As far as I’m concerned, that explanation only indicates that the situation is more dire. Littering is not a conscious decision, say defenders of the sloppy, drunken masses, but an unconscious, habitual one. We do it not because we don’t feel like cleaning up our messes, but because we don’t stop to think about it at all. Littering is second nature. We couldn’t care less.

(A caveat: I speak from experience when I say that anyone sober enough to stand — or, for that matter, to muster the strength to overturn a garbage can — is capable of delivering his or her waste to where it belongs.)

In her new book, “Talk to the Hand,” grammarian-turned-etiquette stickler Lynne Truss suggests that the disgusting habit of littering owes its popularity to the attitude that “someone else will clean it up.” I think that Ms. Truss is too optimistic. I suggest this more cynical analysis of our behavior: Littering is not only a passive insult to the people around us, but is indeed one to the entire world and all the unlucky generations to come.

We don’t worry about littering enough even to snobbishly assume that someone will take care of our messes for us. Instead, we drop chewed gum and empty cups wherever it occurs to us that we don’t want them anymore. If we really were thinking that somebody would be cleaning up after us, then we might think twice. We might realize that, in fact, another organism may very well come to harm if we act irresponsibly. After all, we humans aren’t all bad. We ought to pity ourselves for growing up so miserably trained in the care of the Earth.

We’ve all been told not to litter because if everyone did it all the time, then the world would be one big old mess. That may be true, but it is our generally careless mind-set that presents the greater problem. Stepping in gum is annoying, but spitting it out without thinking is devastating. We live on a planet that is covered in landfills and shrouded with toxic gases. We take its oil only to spill it into the ocean and its coal only to burn its smoke into the air.

Of course we litter; our lifestyle depends upon littering on the most enormous scale. But maybe the only way to halt our destruction of the Environment (yes, with a capital “E”) is to treat our immediate surroundings with vigilant respect.

Helen Vera is a senior in Jonathan Edwards College. Her column appears on alternate Fridays.