Illustration by Kyla McCallum

The Broken Clock

Going from changing with the seasons to changing the seasons themselves

A Traveler’s Guide to the End of the World is a monthly column about the future of climate change.

MAYBE YOU, LIKE ME, take pleasure in watching the year go round. Where I live, it is hurricane season. Today’s offshore storm means that when I get out from my swim, I am fifty yards down the beach from where I started. As I climb out of the water, I witness a sight I’ve never seen before: an immature black skimmer, born this summer but now almost the size of an adult, just a paler version. That makes it a good day. 

That evening I walk down to the writing shack on the marsh behind my house where fiddler crabs are scrambling everywhere, the males waving their giant claws. The first pulses of the fall bird migration have begun, but the big waves are still coming. This, like every other second of every other day, is a particular moment in a particular turn of the year.

After you’ve known a place for a while, you can see one season in another. It’s not mystical or even that hard. I find it reassuring, or at least it was reassuring. These comings and goings of birds and other animals feel like rituals, but that is not really an accurate description since they are the thing itself, not a reenactment, their lives depending on getting the timing right. These timetables have been fine-tuned over millions of years. In the cocoons of our virtual and electronic worlds, it is easy to ignore these primal timetables, but we lose something when we do.

Phenology, writes Jack Turner, “is the study of the mature naturalist.” Phenology is the discipline of watching phenomena change as seasons turn. After a walk one fall when we were living near  the beach at Cape Cod, I said to my wife, “The seals should be back soon.” Each summer “our” seals migrated to the cooler waters of the Gulf of Maine, and each fall they migrated back. 

The next day, the seals were indeed back, loafing on the offshore rocks. I couldn’t have been more thrilled by a promotion at work—and in a way, that’s just what it was.

Phenology has always been a private science, but lately it has begun serving a public purpose. It’s no surprise that Henry David Thoreau knew the timetables of his place intimately, and it turns out that his meticulous phenological journal notes are now confirming what anyone who has lived through recent non-winters already knows: nature’s clock is out of whack. 

Thanks to Thoreau, we can see some of the changes over the last 170 years or so in one particular place: his hometown of Concord, Massachusetts. Several groups of scientists have recently spent time with his journals, trying to decipher his sometimes-hard-to-crack handwriting to see when the trees and flowers of Concord bloomed a century and a half ago. They are particularly interested in the phenomenon called leaf-out, when leaves bloom on the trees. It turns out, the timing of leaf-out and spring wildflower emergence is connected. Evolution led to understory spring wildflowers often blooming before trees leafed out, because they needed the sunlight to spur their early growth and later relied on their shade. The exquisite timing between wildflower bloom and leaf-out has now been thrown off—thus impeding wildflower abundance. These studies, drawing on Thoreau’s journals, have concluded that leaf-out now occurs about a week earlier than in his time. And Concord has already lost almost a quarter of the wildflower species here during Thoreau’s time. 

How do you focus on the immediate?: Living Downstream from Ourselves 

LAST APRIL I BEGAN a summer’s worth of travel that started two miles from the border wall in Arizona and ended in the smoke-filled mountains of Canada. By heading north with spring, I wasn’t only following the migratory route of various animals; I was also following the northern migration of many of their habitats as climate change pushes ecosystems upward, around, and northward. Everywhere, habitats are on the run. Which means that when we try to aid endangered species, we face a moving target.

This is no longer a new problem. The Audubon Society released a study almost fifteen years ago about more than 305 species of North American birds that were already spending winters farther north, some more than three hundred miles north of their former range. Birds as varied as the golden-cheeked warbler—delicate, private, tiny—and the greater sage-grouse—bulky, ground-dwelling, and famously flamboyant in courtship—faced a problem that in the years since has become increasingly common: their futures are uncertain as climate change plays havoc with their habitats. For sage grouse, it means a continued big squeeze, as their sagebrush habitat, already threatened by development, faces transformation into woodland as the frost line shifts north. The warblers’ troubles are even trickier, because they only breed in one place in the world, the Ashe juniper habitat near the Edwards Plateau of central Texas. 

So scientists have found themselves in the position of trying to predict future movements of both animals and ecosystems. Habitat preservation, never easy, has become even more difficult. The new circumstances require a more active style of habitat management. It will no longer be enough to look back at what historically grew or lived in a place, but to anticipate, through modeling, what will be there next. 

Sam Pearsall, who works with estuarine ecosystems in North Carolina’s Albemarle Sound, calls this “pre-storing” habitat, a kind of climate forecasting that will allow scientists to predict where different species, and different habitats, will be moving. On North Carolina’s coast, this could mean oysters would need to be transported to areas that are not presently salty enough—but will be—and doing something similar with bald cypress and salt marsh grasses. In the West, we can often anticipate a movement not just northward but also upward in altitude.


CONSIDER THE LOWLY marmot. For a hundred thousand years or so, marmots would crawl out of their dark winter dens to nibble on the green world outside. Their timing was exquisite, their internal clocks prodded by the warmth of spring. 

“The salad bar was open,” is how Anthony Barnosky, a University of California paleoecologist, put it. “But now with warmer winters, they wake early and stumble out into a still snow-covered world. They starve.” 

Many species will not have the luxury of simply migrating northward. In extreme cases, when species are stranded in patches of habitat, translocation—the actual moving of the threatened animals—will be necessary. Many experts, Dr. Barnosky included, are sensitive to the fact that this overly managed world might seem somewhat “unnatural,” and he recommends simply leaving some wilderness lands as they are. But Barnosky also stresses something every scientist I have spoken to recently repeats: we created this problem and we must help alleviate it. 

This will require sharpening tools we already use, while at the same time creating new tools. In fact, the art of preserving nature may have to become almost as adaptable as nature itself, as we, along with the golden-cheeked warbler and greater sage-grouse, learn to adjust to a changing world.


DURING MY SUMMER journey, I stopped to interview one of Thoreau’s fellow phenologists. In June, I met with David Inouye, a professor emeritus of biology at the University of Maryland at his home above Paonia, Colorado. That morning I had driven from Crested Butte over the Kebler Pass, just opened after winter. Creeks were gushing full, endless young aspens waving green, snow-topped mountains looming huge, and I was caught off guard by a flash of yellow-and-black as two grosbeaks flew in front of the car. The wet year was an aberration, no doubt, variability another symptom of climate change, but my mood rose with my surroundings. This was the West at its finest, lush and green, showing off. 

David Inouye has been watching spring arrive in these parts for five decades, and, unlike most of us, has kept careful track of what he has seen. In fact, since 1973 he has watched and counted flowers in a two-by-two-meter plot of land at an altitude of 9,500 feet near the Rocky Mountain Biological Laboratory in Gothic, Colorado, fifty miles from where we sat. He did this with other scientific collaborators at first, but after a couple years most “had the information they wanted and moved on.” David stayed on and kept going, picking up another set of plots, along with his wife, Bonnie, who began studying a plot of her own. Fifty years later, he’s still checking the plots three times a week. 

“It used to be when I got here after school ended at the end of May, half of the flowers hadn’t shown yet. And so I didn’t miss much. But now on south-facing slopes the snow can be gone by mid-April and they’ll be flowering within days after that.”

He explained that the growing season was starting earlier for three main reasons: warming temperatures, less snow, and more dust-on-snow events. Dust on snow may not seem like much, but white snow reflects heat, whereas darker patches absorb it. This all adds up to a warmer Earth with a shorter winter and less snow. 

When I asked about the marmots, David mildly corrected Dr. Barnosky’s thoughts, pointing out that though their clocks are off, they actually benefit from some of the changes. Because hard frosts come later in fall, marmots can put on another half pound of fat going into hibernation so that fewer actually starve to death. On the other hand, warmer weather has led to foxes inhabiting the higher altitudes, the foxes feasting on  marmots. 

Other species, from moose to mosquitoes, have also moved up to this higher elevation. 

“Seasonality is changing. And it is changing at different rates at different places, which makes it hard for migrators. Spring comes at different times in different places.” 

As for his flowers, David points to the glacier Lilly. Some of the earliest flowers to bloom, including the lilly, do so before bumblebee queens emerge, and so they do not get pollinated.” 

Despite all this, David is no doom-and-gloomer and believes that people are finally realizing that things are changing. He says that he is “mildly optimistic that the changes in behavior will start during my lifetime.”

In the meantime, he will keep tending to his plots.

“The social security agency estimates that I will live to be 83 and I’m 73 now,” he says, “so I tell people that I am going to get ten more data points.”

And the data collecting will continue beyond him as well. His son, Brian, and his daughter-in-law, Nora Underwood—both biology professors at Florida State University—recently began research on the same plots, coauthoring a paper on insect declines in mountain environments. Which means this is generational phenology. With luck, they’ll get another fifty data points.


THINK OF IT. We humans have changed the basic cycles of the years. We have altered the clock of the world.

The bad environmental news beats steadily down on us, but we have small reprieves. How wonderful that Thoreau’s private notes should play a new public role. I think of one of his own favorite metaphors, one he employs on the last page of Walden, that of the “strong and beautiful bug,” whichemerged after lying dormant inside a farmer’s wooden table for sixty years. after having been deposited in the living tree “many years earlier still.” Thoreau concludes: “Who does not feel his faith in a resurrection and immortality strengthened by hearing of this?”

What thrills him is that something—insect or idea—can sleep for decades before springing back into “beautiful and winged life.” And now his journals are doing the same thing, speaking to us 170 years after he spoke to them. It’s true the news they tell is bad, but I can’t help but find the fact that they can speak to us at all is hopeful.

Who would have guessed? Noticing, it turns out, matters.