APRIL 12, 1976
Juncos are back. Crepuscular performance of male woodcocks high above the meadows and pastures. Red maple flowers opening and sugar maple sap still running. Catkins of alder, willow, and aspen are hung, dangling in the wind. Lake ice beginning to retreat from the shore.
DURING THE 1978 MAPLE SUGARING SEASON, back when I was still relatively new to Vermont, my neighbor hitched draft horses to his sleigh and began emptying sap buckets across woodland smothered by snow. He had set his taps by Town Meeting day, the first Tuesday in March, as dependable a sign of spring as the lengthening of the day.
Since 1977, sugaring season has started earlier — and gotten shorter. Sap starts running eight days earlier and ends 11 days earlier on average, according to the Vermont Maple Sugar Makers’ Association. This year, sap started running in late January. Some biologists have begun to wonder if Vermont will remain fit to grow healthy sugar maples.
In the 40 years since I moved to Vermont, I have kept a journal noting (among other things) phenology, the science of seasonal natural phenomena. Over those decades, the seasons that give definition to our lives in New England have changed — often in small, almost imperceptible increments, like watching a child grow, until suddenly you can no longer deny the alterations.
Rachel Carson devoted four pages to climate change in her epic 1951 book The Sea Around Us. “The frigid top of the world is very clearly warming up,” she wrote. “The long trend is toward a warmer earth; the pendulum is swinging.”
Has swung and will continue to swing.
But you don’t need to look to the Arctic to confirm that swing. It’s right here in New England — in our parks, in our gardens, in our backyards.
APRIL 7, 1980
Sunny, sixty degrees. Sap running. At night, twenty-two degrees and six more inches of snow.
BACK WHEN I SETTLED IN EAST-CENTRAL VERMONT, robins, phoebes, and woodcocks arrived by late March or early April. Peepers and wood frogs chorused after the first warm, rainy night of spring, usually the second or third week in April; American toads piped up during the first week in May, when apple blossoms lit the dooryard. If a gray tree frog called before the third week in May, I considered it early. This year, February ushered back worm-probing woodcocks in the fourth week of the month and then sardonically turned the ground to iron; on March 1, as if scripted by Poe, a vanguard of amorous amphibians lured by cordial weather reached the spawning pools in time to brace themselves against a prolonged, macabre (and fatal) March freeze.
In the early years here, we planted frost-sensitive vegetables — tomatoes, peppers, squash, and so forth — over Memorial Day weekend, although an early June frost was not uncommon. Now, they’re in the ground by mid-May.
In the late ’70s, black flies plagued us from Mother’s Day to Father’s Day. Now, they appear in my garden on warm late April afternoons, when I fuss over lettuce and peas. Mosquitoes appeared in late May (instead of year-round in my basement, as they do now), deerflies and horseflies in late June, no-see-ums in high summer. Throughout the ’80s, ticks were rare; I’d pluck one or two per summer from my dog. Lyme disease was little known and coastal.
Some years, frost visited our garden before Labor Day. We’d have to scramble to insulate the basil with sheets of newspaper (or make pesto all night), and we’d harvest every reasonably ripe tomato and pepper. Color began earlier then, igniting the outer branches of wetland maples in late August, flashing across the hills by mid-September, and more or less extinguishing itself around Columbus Day. Now, killing frost may not visit my garden until mid-October, and color lingers into November.
Traditionally a two- or three-day respite, January thaw lasted three weeks this year, extending well into February, which the National Oceanic and Atmospheric Administration (NOAA) called the warmest February on record in the Northeast. Forty years ago, you skated the Connecticut River 8 miles to Hanover. Collectively during the past two winters, the Connecticut opened and closed seven times. This February, there was no ice at all, not even along the river’s rim, and then, during the first week of March, the river froze shut . . . again.
I remember a February night in 2012 — it was as dark as pitch and snowing hard, those big, wet, gummy flakes that stick to everything. I was at home, sitting downstairs, when I noticed a flash of light on the snow. In quick succession, I checked for the source: Computer was off; porch lights were off; the propane furnace was behaving. I didn’t smell smoke. No snowmobiles crossed the lower pasture. No flickering electric lines (that I could see). Flummoxed, I went outside — and waited.
What I found was a winter sky flush with electricity. Volleys of lightning screened by falling snow flashed off everything white (which was everything) as if fireworks strobed overhead, an atmospheric disco. Light . . . dark. Light . . . dark. Spellbound, I stood on my porch enchanted by my first-ever thunder snowstorm; each lightning flash cut a tunnel of blue-white light, eerie with phosphorescence, through the otherwise dark night.
APRIL 8, 1983
I heard peepers. Not the maddening chorus, just a few males that reached the nuptial pools ahead of the mob.
MARK BREEN, SENIOR METEOROLOGIST for the Fairbanks Museum and Planetarium in St. Johnsbury, tells me that during the past 20 years, there’s been a sharp decline in the gap between winter minimum and maximum temperatures. Winter nights are warmer, allowing the atmosphere to hold more moisture, which increasingly appears as freezing rain, purveyor of treacherous black ice. Driveway sanding has become a regular part of my winter chores.
Cameron Wake, a climate scientist at the University of New Hampshire who tracks New England weather patterns the way a Wall Street broker tracks the Dow, agrees with Breen that winter, more than other seasons, has become warmer and seemingly less predictable, particularly after dark. Taken from Wake’s research: The earliest ice-out record for Lake Sunapee and Lake Winnipesaukee was March 23, 2012; the latest for Winnipesaukee: May 12, 1888. Today, on average, both lakes unlock a week or two earlier than they did in the late 19th century. Since the beginning of the 20th century, he says, the growing season in southern New Hampshire has lengthened by as much as four weeks.
Richard Primack, a professor of plant ecology at Boston University, has spent more than a decade documenting evidence of climate change in and around Eastern Massachusetts, including Arnold Arboretum, Mount Auburn Cemetery, and Manomet Bird Observatory in Plymouth.
Primack’s big break came when he mined the records of Henry David Thoreau.
In spring 2004, Primack began to record blooming and leafing dates, and around 2009 he started looking at the arrival of migratory birds in Concord. Next, he compared those dates with the ones he unearthed in the journals of Thoreau (a phenologist himself), a climatic yardstick that extends back more than 160 years. Primack found that in the 1850s, migratory birds began to appear on average four days before most trees and shrubs leafed out. Today, leaf-out often happens 10 days before the arrival of the birds, and wildflowers bloom, on average, 12 days earlier than they did in Thoreau’s time.
I recently drove to another Concord, the New Hampshire capital. When St. Paul’s School opened a new science and math building there in 2011, it suspended a sphere nearly 6 feet in diameter from the ceiling of the third-floor conference room. NOAA designed the globe, called Science on a Sphere, as a screen on which four projectors mounted 90 degrees apart transmit computer-coordinated images. The high-resolution animated images, derived from planetary data sets, flow across the globe, creating what’s called a spherical projection.
Watching, I felt like an astronaut. Day began to move across the globe, awakening continents as though a curtain were lifting. This replica of Earth almost seemed to breathe: White clouds gathered and dispersed over blue oceans and green and brown continents in a time-lapse dance, a window with views into the past and the probable future. On-screen, circa 1990, Arctic sea ice began to shrink. Grimly fascinating, like a white beating heart, ice spread in winter, vanished in summer, winter maximums shrinking as time advanced. (Though not as dramatic, NOAA could have substituted shrinking lake ice on Winnipesaukee or Champlain, and perhaps for us in New England, it should.)
It was all in front of me, on a disquietingly spinning carbon fiber Earth, a three-dimensional glimpse into a future we deny at our peril.
APRIL 23, 1999
The first warm rainy night has thawed the ground, ephemeral woodland pools come alive as wood frogs, by the hundreds, return to the water to breed, a ritual that goes back at least to the thawing of the last glacier. I’m drawn to the frogs by their nascent swell of life, their maddening urgency, their unmitigated mayhem.
EARLY JULY 1980, an oppressively hot Thursday — two days before my wedding. I scramble around a rock slide above the Connecticut River, a steep, wooded area in West Lebanon, New Hampshire, known locally as Boston Lot. I’m here to verify a turkey vulture nest, which I smell before I see it: a nook within the rock slide littered with bones and scraps of putrid flesh. Two fluffy chicks, as tall and plump as chinstrap penguins, stand in the foyer, hissing . . . and reeking. This is the first confirmed vulture nest in northern New England.
When Theodore Roosevelt camped out at the White House, turkey vultures barely nested north of the Mason-Dixon Line. In 1938, Tudor Richards, later the first executive director of New Hampshire Audubon, called them infrequent visitors that were reported every few years in the southern part of the state.
What encouraged turkey vultures to expand their range all the way into southern Canada — and into the consciousness of everyone who fixed on the huge, ash-colored birds wheeling and drifting like oversize paper airplanes?
At first, I assumed that the astronomical increase in white-tailed deer in the Northeast bundled together with the creation of interstate highways (in the late ’60s) must have provided an enticing and dependable smorgasbord of road kill. Then I recalled how infrequently I’d actually seen a vulture loitering amid crows and ravens (and occasional bald eagles), all of which attend virtually every I-91 road kill in Vermont. Something else had urged vultures north, something as primal as food, something formerly stable to which the birds are irrevocably moored: a reconfiguring of their aerial world, a reconfiguring of the forces that sustain their flight.
Since the turn of the 19th century, progressive climate change has generated ever more powerful columns of heat that raise air off rock and road. Meteorologists call these warm flickering bands of air “thermal currents” or simply “thermals,” which are to summer what snow is to winter: an emblem of the season.
Thermals are easy to spot. Look for big white cotton-ball clouds; each rounded mass marks the roof of a thermal. When thermals chill, rising stops and moisture condenses into a deliciously morphing flotilla . . . Rorschach clouds. Capable of hours of flapless flight, a vulture drifts from thermal to thermal and along updrafts that bank off our corrugated landscape.
When I returned home from St. Paul’s after the visit with that unsettling climate change globe, I checked Vermont eBird records, the largest citizen-science project in the state and part of a global biodiversity databank, for trends in turkey vulture records.
I found that between 1980 and 2007, their approximate average date of arrival in Vermont was March 13. Then, between 2008 and 2017, February 13. In 1980, the last seasonal sighting for a turkey vulture was September 25. More recently, they linger well into November, sometimes December. In fact, a turkey vulture may now be spotted in any month of the year hanging above Vermont farmland.
APRIL 7, 2016
Only the third male cardinal I’ve seen in 19 years in my front yard in Thetford Center. The bird feasted on sunflower seeds spilled from the feeders by siskins and goldfinches. I watched it for a minute or two, and then it was gone.
Ted Levin’s most recent book, “America’s Snake: The Rise and Fall of the Timber Rattlesnake,” was selected by Forbes as one of the 10 best conservation books of 2016. Send comments to email@example.com. Follow us on Twitter @BostonGlobeMag.