I’ve made a lot of cross-country flights in the last few weeks, the most recent taking me home to New Jersey and then out to my cousin’s wedding (congrats, Jason and Olivia!) at the edge of the Corn Belt. When I’m not catching up on sleep or contemplating my hypocrisy as my carbon footprint balloons by the minute, it turns out that gazing out of an airplane window is one of my favorite ways to relax.

Today, still on the tarmac, I’m looking at gray skies and a gentle drizzle. The landscape extends, flat and smooth, to a gently curved horizon. I know that when we take to the air, in those few moments between achieving liftoff and punching through the cloud cover, I will see corn and soybean plants filling those endless miles. Eventually, passing west, the square-shaped, tree-dotted fields will give way to the brown-edged circles of modern irrigation. Still farther, we’ll pass over vast acres of rangeland, zoom across the deserts in the rain shadow of the Rocky Mountains (some of the prettiest landscape I know from the air), skip across the Central Valley, dip down and tilt right, and touch down in SFO at precisely the moment I think the plane will find the waters of the bay before the end of the runway.

I think about when I first began to find the American landscape troubling rather than fascinating — and often beautiful. The memories invariably lead to David Ehrenfeld’s conservation ecology class and the lectures on factory farming, cheap oil and sustainability that inspired my first Seeing Green columns.

Amber waves of grain became symbols of our global dependence on industrial agriculture. Purple mountain majesties became the last refuge of species squeezed by climate change.

Today, we rely on our park systems to remind us of a long-lost past and take modern infrastructure for granted. In the shifting baselines of our perceptions, we rarely ask what’s been paved over by roads and shopping malls. Where our uncles once competed to catch the biggest fish, we never think to drop a line. Where our grandparents once came to the stark edge of civilization, we now zoom by arching overpasses.

But we have to call these views into question. We have to ask ourselves what things used to be like and how they have changed. That’s the only way that we’ll be able to keep some track of reality, the only way we’ll tether ourselves to the ground on which we’ve built. That’s how we’ll remember that New Orleans will always be flood-prone, why some crop fields lose fertility faster than others, which plants tolerate drought and which tolerate cold. And so when baselines shift and times change again, we’ll be able to use our past knowledge — not just our present — to help us adapt.

We’ll also be better equipped to decide whether the changes we’re witnessing are for the better. Most of us respond to change with suspicion. We like our comfortable routines. And we’ve grown up hearing our relatives sigh over “the way things used to be.”

Whether things are improving or going downhill is a matter of personal opinion. But I’ll leave you with one gray story, a mixed bag of blessing and curse, first told to me five years ago by Ehrenfeld. It’s the story of the Green Revolution, responsible for the vast crop fields now passing 10,000 feet below me.

Once upon a time (i.e., in 1798), a man named Malthus predicted that the growing human population would quickly outstrip its ability to grow food for itself. While the human population has doubled several times since his ominous words, his predictions of widespread famine have not come to pass. That’s largely because by the 1960s, through the work of Norman Borlaug and others, we’d bred high-yielding (if rather needy) crop lines that double or triple the output of an acre of land.

In our rather pessimistic present, we often look at this Green Revolution with disdain: nurturing these crops requires a huge capital investment, extensive irrigation, heavy doses of fertilizer and pesticides, and so forth. Worse, it’s a fundamentally unsustainable operation that relies heavily on cheap fossil fuels.

But maybe we’re forgetting — because few of us have seen it ourselves — what it’s like to be truly hungry, what it means to be starving. We’re forgetting what a boon it was to save upwards of a billion people from that fate. And we’re forgetting that, by intensifying the use of existing farmland, we’ve spared land (some of it now tucked away into parks and preserves) that would otherwise be under the plow.

Ask yourself: for better or for worse? And what happens next?

Meanwhile, I’ll return to my view, where the cloud cover below has fallen away and a series of wind turbines march across the landscape. They are a new addition: baselines have shifted and things have changed. And depending on how you weigh migratory birds against alternative energy, you might even say they’ve changed for the better.

Holly Moeller is excited to See Green — though hopefully not from the air — for another quarter. Send comments, carbon footprint comparisons and other inquiries to [email protected].