A version of this story appears in the September 2020 issue of National Geographic magazine.
It’s still dark, and well below freezing, when Kristie Leavitt pulls to a stop and turns off the 4x4’s rumbling motor. For a moment, there’s no sound in the world but the faint whisper of wind sweeping over the ice. The navy blue sky begins to lighten. The cold air burns in her lungs.
Bundled in a hot-pink coat that matches her fishing hut and gear, Leavitt hops down from the driver’s seat onto the 18-inch-thick ice that covers this corner of Munuscong Bay, in Michigan’s Upper Peninsula. Her boots crunch into a thin layer of snow as she begins the ritual of preparing for her favorite activity: ice fishing.
Leavitt is among the two million ice anglers in the United States who look forward all year to the chill of winter. Like many others in the region, she also relies on the cold for a living. She manages her family’s tourist cabins and bait shop on the edge of the bay, and the businesses make most of their money during the ice fishing and snowmobiling season.
But what Leavitt is doing today is a rare occurrence this year in the Great Lakes region. The long-term average for ice coverage on all five Great Lakes is 55 percent. This winter, ice covered only about 22 percent of the lakes’ surfaces—a near record low.
Some lakes didn’t freeze at all. Others saw only faint traces of ice around their edges, or froze for only a short time before the ice melted away. The weekend before Leavitt’s outing, temperatures in the region shot up to 40 degrees Fahrenheit, and ice anglers slogged through slush in T-shirts.
One over-warm season isn’t necessarily a harbinger of inevitable change. But increasingly, scientists can pick out patterns in the scattershot records of change from across the Great Lakes, and those patterns are pointing toward a sobering conclusion: This winter, with its faint traces of ice, is likely just a taste of the future to come.
The long history of the lakes, shaped by climate
The five Great Lakes—Superior, Michigan, Erie, Huron, and Ontario—collectively account for about 20 percent of the fresh water on Earth’s surface. For perspective: That’s an amount so vast that it could cover the entire United States in nearly 10 feet of water.
The lakes’ geographical footprint is also hard to fathom. Their combined surfaces span more than 94,000 square miles, about the size of the United Kingdom. The combined measurement of the coasts of all five lakes is thousands of miles longer than either the Pacific or Atlantic coastlines.
The presence of all that water was shaped by natural changes in Earth’s climate through deep time.
But the lakes are now facing a new, unprecedented future, and this time, humans are behind it.
All in all, the planet has warmed by an average of 1.8 degrees Fahrenheit (1 degree Celsius) since 1900. The Great Lakes region is right on track with this global trend: Within the basin, air temperatures have risen by an average of 1.6 degrees Fahrenheit compared to the first 60 years of the 1900s. And much of that warming has been concentrated in the winter months, nudging the ice ever closer to its tipping point.
“Lake ice is an amazing indicator of climate,” says Sapna Sharma, an environmental scientist at York University in Toronto. “Ice freezes when temperatures are below zero. It’s such a clear indication of climate change—and people have recorded it, in some cases, for centuries.”
In Japan, priests at a Shinto temple have kept an almost 700-year-long record of when their lake freezes solid. Natural climate cycles emerge from that record—dwarfed in recent decades by the human-caused warming that has gripped the planet. Merchants who used Finland’s Torne River for trade kept track of the date the ice broke up each year from 1693 onward.
In Lake Superior, shipping companies whose boats need open water also have kept records of ice formation and breakup since 1857. In all these records, there’s a lot of bouncing around—cold years with long stretches of early ice, warm years with less. But the short-term bounces build up into a distinctive signal of human-caused warming starting after the Industrial Revolution.
“What’s happening in the Great Lakes region is a small part of a bigger story,” says Lesley Knoll, a lake expert at the University of Minnesota’s Itasca Biological Station who spends part of her time studying the cultural relationships people have with frozen lakes.
Kristie and the lake
For Leavitt, 32, the ice has always been a place to bring her life into focus.
When her family would drive up from downstate to visit her grandparents, who owned the lakeside camp at the time, she would layer on warm clothes, collect a small cooler of minnows from the bait shop, and walk out onto the ice as far as she could get. She’d crank her hand-powered auger, cut a channel through the thick ice, and open up a portal to the quiet underwater world.
The old-timer at the bait shop had handed her a rod off the wall the first time she’d gone in there. He showed her how to tie a lure, and how to tip the rod up and down to make the lure and minnow glitter in the water’s depths. That first rod, a scant three feet long, hangs on the wall of her shanty to this day.
Back then, it was a simple affair. She’d bring what little equipment she had out to the ice, perch on an overturned five-gallon bucket, and sit there for hours, tipping the nose of the rod up and down like a conductor’s baton, calling to the symphony of fish below. She didn’t catch much. But the feel of it—the clouds skidding overhead, the water changing colors below her feet, the wind swishing past—got locked into her brain as the platonic ideal of winter.
Leavitt is far from alone. The ice provides crucial things for everyone who goes out on it. Respite for some, a dearly held recreation opportunity for others, food, and much more. Around the Great Lakes, ice is also a critical component of the local economies; a recent estimate says winter tourism accounts for some $3.5 billion across the region. A single ice fishing tournament can bring in hundreds of thousands of dollars to the local communities.
But in parts of Lake Superior, the ice season has been shrinking by an average of almost a day each year for the last few decades. That means the year Leavitt was born, a winter on Superior would have included nearly a month more ice cover than it does today. Superior is also warming faster than just about every other large lake on the planet, second only to Lake Fracksjon in Sweden.
The other Great Lakes’ ice seasons are also shrinking: All are shortening by an average of about half a day per year. The waters are warming as fast as or faster than the air around them, which has risen about 1.6 degrees since the beginning of the last century. That number may sound small and benign, but it masks much more critical changes in a place where the line between ice and no ice, snow and rain, can be razor-thin.
It’s difficult to see the change clearly, in some cases, because there’s huge year-to-year variation, says Jia Wang, an atmospheric scientist at NOAA who focuses on ice cover in the Great Lakes region. Though they’re thousands of miles from the oceans, the Great Lakes feel weather influences from both the Pacific and the Atlantic and incorporate these weather patterns into their own tangled mishmash.
So, though one year may be warmer than the one before, some winters in recent history were icy cold. In 2013-14, the polar vortex carried frigid air from the Arctic down into the continental U.S., and the cold stretched well south of the Great Lakes. The ice grew feet thick in parts of the lakes, and total ice cover spanned more than 90 percent.
The extra tricky part is that the presence and growth of winter lake ice each year is a complicated sequence of events. Maybe it gets cold enough for ice to form early in the winter—but if a stretch of bitter wind keeps the water’s surface churning, the ice will form later. Maybe the summer before was extra warm, zapping enough extra heat into the water that it takes it extra-long to cool off and get to the point when it can start to freeze. Maybe a bunch of snow falls early in the season, insulating the ice from the top and, counterintuitively, keeping it from growing quickly through the cold temperatures.
But there are some factors that aren’t so complicated. The air is getting warmer. So is the water, in many places faster than the air. Across the Northern Hemisphere, nearly 15,000 lakes that used to freeze solid each winter have begun to freeze intermittently, if at all.
A future less frozen
The real question is, of course, the future. Winter is embedded in this place. It’s integral, non-negotiable, definitional.
The warm days in mid-February draw Michiganders outside, but there’s an uneasy undercurrent to their enjoyment. “We like it when it’s nice like this, but it’s not real winter unless it’s like, minus 40,” says Kasey Spencer, a lifelong Upper Peninsula resident. “When it’s cold, we’re miserable—but we’re also really happy, you know? If we have a really warm winter, it feels like something’s wrong.”
What the future holds is both more and less. There’s more heat in the air, trapped by the greenhouse gases humans continue to pump into the atmosphere. Predictions for the region forecast air temperatures to rise by another 1.5 degrees or more by 2045, and somewhere between roughly six to 10 degrees by the end of the century. There’s also more heat in the water, forced in during hot summers and longer stretches of warmth.
However, by the end of the 2030s, some scientists predict that there will be 15 to 16 fewer days with the maximum temperature below freezing in the Great Lakes region. By the 2050s, we’ll add another few days to that total. By the end of the century, depending on the strength and aggressiveness of climate actions taken, the number of days below freezing each year is likely to drop by somewhere between 21 to 33.
In the 2015 Paris Agreement, countries agreed to try to limit planetary warming from surpassing 3.6 degrees Fahrenheit (2 degrees Celsius) beyond pre-Industrial levels. Even if those goals are met, Sharma estimates that more than 35,000 Northern Hemisphere lakes could lose their consistent winter ice. If warming shoots past that target, the number balloons. Under the most dire scenarios, more than 200,000 lakes could lose their ice.
“Things like ice and water have a long memory,” says Richard Rood of the University of Michigan, who focuses on the complicated ways climate change is playing out across the Great Lakes region.
“What we’re seeing is some systematic increases in temperature over the long run, putting you closer to freeze-thaw cycle of water. And you’re seeing winters getting warmer, shorter—so you just don’t have the amount of time you used to for thermodynamics to do their thing.”
If the water doesn’t cool down enough during the winter, it gets warmer, faster, in the spring and summer. Over time, and especially as the climate keeps up its inexorable warming, the system could wind itself up more and more—a self-reinforcing loop.
“At some point these areas that maybe sometimes get ice and sometimes don’t, they’re going to transition to never getting ice,” Knoll says. “How are people going to interact with those water bodies when they never get ice at all? How are they going to adjust? How are their lives going to change?”
Leavitt, like many others up here, hesitates when she starts to talk about the future. The world as she sees it is still ice-covered; each year is another open-ended opportunity for cold. But sometimes, the concerns bubble up, at least quietly.
“Sometimes I just don’t know,” she says slowly, leaning forward over the tip-up she’s setting on an open hole, strands of hair wisping around her intent face. “Will all this still be around when I’m 70?”
Amy Sacka is a documentary photographer based in Detroit whose work focuses on the people, culture and environments of the Great Lakes. Follow her on Instagram @amysacka.
Editor's Note: This article originally misstated the degrees Fahrenheit that signatories of the 2015 Paris Agreement agreed to try to limit a warming increase to. It was 3.6 degrees Fahrenheit (2 degrees Celsius) beyond pre-Industrial levels.