Cold, white wilderness surrounds Toolik Field Station, a world-renowned Arctic research outpost deep in Alaska’s interior.
It’s a cloudy March afternoon with a wind chill of -20°F as scientist and Michigan Engineering alum Brie Van Dam treks up a mountain that overlooks the station.
In some directions, it’s hard to tell where the ground ends and the sky begins. In others, frosted ridgelines jag across the horizon. The only signs of civilization are the distant camp buildings and the single road that cuts a dirty path through the snow. The closest villages along it are two hours away.
Van Dam (BSE AOSS ’07) is in the midst of a five-hour excursion – most of it on snowshoes – to document the ground cover at a plot near the top. Tiny icicles are crystallizing on her lashes. Condensation from her breath is solidifying on her scarf. While she’s weathered lower temperatures, she knows not to stay still for too long. That’s when the chill can get dangerous.
Harsh and frozen: the Arctic’s been this way for most of the past 55 million winters, including, of course, the most recent 10,000 during which humans, enabled by Earth’s modern climate, have flourished and multiplied to seven billion. The region’s store of ice, both on the sea and land, stabilizes the planet’s temperatures in a host of important ways. You might think of it as the mortar in the foundation of the climate as we know it.
But the foundation is cracking. The Arctic is warming faster than any other place on Earth. Not only is it heating up more rapidly, the pace of change is speeding up. Melting ice is melting more ice and touching off tangent cascades along the way: Permafrost is thawing and freeing more greenhouse gases. As the northern waters warm, climate-regulating currents in the ocean and air are slowing. All while the seas are rising. The consequences of Arctic warming are rippling across the globe, and they’re on track to keep escalating exponentially.
“It’s easy sometimes as a scientist to look at things through the science lens of: ‘Oh, wow, what a cool time to be studying the Arctic because the Arctic is changing so fast right now,’” says Van Dam, who manages the station’s Environmental Data Center. “But when you look at that through more of a human lens, it becomes honestly really terrifying.”
Van Dam faces these facts every day in her work documenting climate change from its epicenter, year-round. She’s a member of the skeleton crew that stays at the station through the coldest months. The winter yields pivotal insights, and the most recent was the warmest in recorded history.
In the snowpack samples she gathers, in the wing prints of the local birds and even in the patterns the wind makes on the powder, the snow, Van Dam says, tells stories. She is paying close attention. Her monitoring work is, pixel-by pixel, helping to paint a climate picture that you have to stand way back to see.
Scientist and Steward
Van Dam has been connected to the snow for much of her life. As a child, she and her brother built igloos in Michigan winters. As a doctoral student at the University of Colorado at Boulder, she studied how sunlight reacts with pollutants in the spaces between fallen snowflakes.
She first set foot in the Arctic while she was an undergrad at U-M. She spent a summer in Alaska’s wilderness through an outdoor education program. During that trip, she helped rescue a fellow student from a glacial crevasse – and she fell in love with the far north. She connected with its raw nature, its dangers accompanied by stark beauty and otherworldly light.
“I did really ‘fall in love’ with the landscape,” she says. “Love is a verb, right? It’s something that we do, and so loving the landscape, for me, means really being a part of the environment on a personal level.”
In addition to her role as a scientist, Van Dam is a steward of the world around her.
When she’s not at the field station, she lives in a cabin in Fairbanks that has no running water. Such set-ups are relatively common in interior Alaska because the frozen ground is difficult to plumb through. She gets her water for drinking and washing dishes and clothes by refilling giant jugs in town once a week. The outhouse is out back and, in Van Dam’s case, the shower’s at work in her local office. While it’s not the most convenient approach, it’s easy to conserve when you don’t have a tap.
Van Dam’s freezer is stocked with the meat of a caribou she killed in the Brooks Range. She and a hunting partner skinned it, quartered it and hauled it home on a sled.
“I showed up to my Fairbanks office still smelling of caribou blood,” she recalls.
That animal, and wild salmon caught by a friend, will be her protein for most of the next year. Industrial meat production is a major carbon emitter and as much as she can, Van Dam opts out of that cycle.
“The idea that our species – that really, my actions and choices – are having an irreversible impact on the planet kind of blows my mind sometimes,” she says.
Back on the mountain overlooking Toolik Field Station, which is funded by the National Science Foundation and part of the University of Alaska Fairbanks Institute of Arctic Biology, she stops at the top in sub-zero temperatures to gather data. About once a month, she takes pictures of landscape conditions at several plots for researchers studying two tundra plant species. They’re documenting how climate change is affecting the global range of a particular moss and an alpine herb.
She could take a snowmobile the two miles to the base and back, but she prefers to cross-country ski or snowshoe, knowing that the only carbon dioxide she adds to the atmosphere comes from her own breath. It’s a long journey for a set of photographs. But it’s an important one.
Winter is the longest and most critical season in the Arctic. It’s when ice platelets on the sea coalesce until stretches of ocean are frozen over. It’s when snowpack accumulates. In some places, the new layers add girth to glaciers. In others, snow insulates the ground, preventing soil from re-freezing and losing the heat it collected in summer.
Winter is also the station’s sparsest. Though more than 100 projects are typically underway at any given time, almost none of the researchers involved are able to get there for regular observations. So Van Dam stands in, looking in the nooks and crannies for small signs of the bigger changes afoot. She’s a crucial set of eyes.
Polar Ice and the Global Thermostat
Polar Ice and the Global Thermostat
The Arctic is a place of extremes and opposites – frozen but melting, vulnerable but hardy. It’s the 7 million square miles north of the Earth’s 66th parallel where the sun doesn’t set on Midsummer Eve or rise on the winter solstice. It’s an ocean ringed by the coasts of eight countries.
The top of the world is feeling the heat much more so than the Antarctic, where the ice is thicker and higher, and a frigid ocean current encircles the continent, keeping warmer waters at bay.
Comparatively, the sea ice and snowpack up north are thin. And the records here are breaking as fast as that ice is.
Month by month, 2016 is on track to be the warmest year on record. Globally, temperatures have exhibited the greatest departures from average since recordkeeping began in 1880, according to NASA. January was nearly two Fahrenheit degrees warmer than average, February more than that. But over the Arctic, the anomalies during those two months were staggering – more than 7.2°F.
“The changes occurring in the Arctic are nothing short of startling,” says Jennifer Francis, a climate scientist at Rutgers University. “They encompass all aspects of the system.”
Francis calls the shifts “disturbing,” and not just for the region itself and the 4 million people who live here.
“What happens in the Arctic doesn’t stay in the Arctic,” she says. This is true in many ways, but in particular, the melting of ice and snow cover is destabilizing a vital mechanism in the global thermostat. Snow bounces back 90 percent of the solar energy it’s exposed to. Sea ice reflects between half and 70 percent. But the ocean returns only 6 percent. It absorbs the rest of the heat like blacktop in the summer. So the more snow and ice that melt, the more heat the newly exposed surfaces hold onto, which leads to higher air temperatures – and more melting.
Reading the Snow
It’s a frigid March morning outside the Environmental Data Center – one of the high-tech trailers on the 30-acre campus of the field station. Van Dam is packing for a day of measuring the snowpack. She loads her tools onto a utility sled. They include an ultra-precise ruler, a coring column, a notebook and a pencil (because pens can get temperamental in these temperatures). She secures it all with bungee cords.
She steps into cross country skis, reaches down to the sled’s rope, lifts it up and clicks the harness around her waist. Poles in hand, she muscles off, her purple shadow leading her into the white expanse, skis squeaking against the snow.
Today’s work takes Van Dam a mile and a half from camp to what she calls vegetation phenology plots – designated spots where she monitors the environment through the seasons. In the winter, she measures the snow, including its depth, density and liquid water content. Researchers from all over the world with projects at the station can use the data Van Dam gathers to put their own findings into context.
This kind of routine information gathering is “vitally important to understanding the behavior of the climate system,” writes Henry Pollack, a U-M emeritus professor of earth and environmental sciences in his climate history and cautionary tale, A World Without Ice. “But this type of scientific work is not glamorous.”
When Van Dam and her sled arrive at the first sampling site, she throws a down jacket on top of her other layers. She won’t be as active here as she was on her commute, and temperatures are in the teens. A warm winter is relative here.
Before she gets to her task, she pauses to point to a trail of bird footprints.
“If you look right here,” Van Dam says, “the ptarmigan was walking walking walking, and you can actually see the wing prints from when it took off. Isn’t that beautiful?”
They were scattered all over the sparkling surface, deep divots and quotation mark grooves becoming shallower and fewer as the birds took flight.
"One of the things I really love about snow is it tells you stories. You can sort of read it.”
She begins her more rigorous reading by measuring how deep the snow is. She dips the scientific ruler into the snowpack at 50 different points and records the millimeter markings in a journal. Moving on to density measurements, she unpacks a hollow metal tube with a T-shaped grip called a “Federal corer.”
She drives it in, twists it, and lifts out a snow plug. She pours the contents into a plastic bag. Then she does it again. And again. She gathers 20 cores at this location.
Van Dam gears up and heads over to the frozen Toolik Lake, just south of the first sample site. She measures more snow there. And when she’s done, about three hours after she had left the station, she loads 25 bags of snow onto the sled, attaches the harness and swishes her skis across the solid lake surface to tow it all to the data center.
When she gets there, Van Dam weighs each sample, then all of them together. Eventually she appears in the doorway of her office trailer with a bag of snow held high. “You see all that work?” she asks.
She dumps the contents into the growing mound out front and laughs. The data she needed from those ice crystals is in digital form on her computer.
Once she did the math, the snowpack of the station turned out to be a bit shallower than it’s been in recent years. The average depth of about 10.6 inches is the lowest since her office started gathering data in 2012. Granted, that’s not a very long historical record, but one day it will be. Researchers will refer to it as they work to understand what used to be, and how different the climate of the 2010s was from the climate of the decades to come.
In addition to helping scientists identify change in the climate system, ongoing monitoring can also raise red flags that researchers’ projections need to be revised. That’s key as humans plan to adapt.
The Tipping Point and the Icebergs
One recent revision is the estimate for how quickly the ice will melt. For a long time, scientists have had a broad understanding of how melting snow and ice would exacerbate climate change. What they didn’t realize was that ice dynamics are remarkably complex, and the feedback loops don’t always lead to gradual change.
“Just as a small tree branch will bend a little when a boy steps on it, and bend a little more when his (friend) joins him, everyone knows there is a limit to the loading beyond which the branch no longer bends – it snaps,” writes Pollack, who conducted research at Toolik Field Station in the ‘90s.
Three feet of sea level rise by 2100 is the Intergovernmental Panel on Climate Change’s standing estimate. But ice has been turning to water on both poles much more abruptly than climate models predicted. Ongoing monitoring from satellites has brought this to light. And Jeremy Bassis’s work has helped explain why.
For a long time, ocean rise estimates have ignored a phenomenon that accounts for roughly half of the mass lost in ice sheets. That neglected process is iceberg calving – bergs detaching from land-bound ice and glaciers. It’s been left out because it wasn’t clear what factors were involved, explains Bassis, an associate professor of climate and space sciences and engineering at U-M.
Bassis has identified the physics at the heart of iceberg calving. Now researchers are relying on his equations to more accurately simulate how soon we can expect the oceans to lap at our coastal roads and porches.
Newer estimates say three feet this century is an unlikely minimum. A better bet is twice that – six feet in the next 85 years followed by a foot per decade. Compare that to the current pace of about an inch per decade, a pace that’s already causing Miami Beach to spend up to $500 million on a network of walls, raised roads and pumps to fight periodic flooding at high tides.
“I think that the big surprise for those of us who study ice is that it turns out we’re talking about shorter time scales to make significant changes,” Bassis says. “We used to think on the order of 1,000 years. Now the estimate is within centuries, but we can’t rule out decades.”
It’s happened before, Pollack says. Scientists can tell by studying fossils of coral reefs that some 120,000 years ago, during the end of a warm interval in between Ice Ages, the seas rose eight feet in 50 years.
The cause of this flash melting, Pollack says, was “extremely rapid sloughing of ice into the sea.” Recently, both Greenland’s and Antarctica’s ice sheets and glaciers have been surrendering at alarming rates.
That’s all to say that snow and ice seem to be foreshadowing dramatic turns in the climate story.
Peril in Permafrost
It’s true both above and below ground. Though the dirt at Toolik Field Station is covered with snow today, researchers – supported by Van Dam – are examining how the soils are reacting and contributing.
In a hooded parka and thick cargo pants, Van Dam kneels by the station’s weather sensors. She needs to replace some equipment, and it’s buried in snow.
Her task is to swap out an electrical box and two ultraviolet light sensors, as well as the wires that connect them through a protective pipe, which is also buried. Nothing’s broken. She just has to send it all to the manufacturer to get it calibrated periodically.
With a shovel, Van Dam carefully cuts into the snowpack around the electrical box. Then she hoists up blocks of frozen snow and tosses them behind her.
“I don’t want to just dig it all out with the shovel,” she explains, leaning shoulder-deep into the drift. “I have to make sure I don’t cut any wires.”
The weather station does a lot more than tell the locals how cold it is. The ultraviolet sensors, for example, are helping U-M researchers study how sunlight affects permafrost – a thick layer of frozen soil and plant matter under the snow Van Dam is excavating.
Permafrost comprises about a fifth of Earth’s land area. Though it sounds more enduring, it technically refers to soils that haven’t thawed for at least two years. Much of it, especially in the coldest parts of the world, is far more ancient. Alaska holds a Russian variety called yedoma. It formed during the most recent Ice Age more than 12,000 years ago when glaciers overtook green valleys and grasslands.
Guess what: It’s also thawing much faster than scientists expected. Not only is this a problem for the infrastructure on top – think oil pipelines, roads and homes – it’s another global warming consequence that leads to more of the same.
The icebound plants, which were covered by dirt at the pace of about a meter per millennium, are stores of carbon. When they finally defrost, microbes in the soil will break them down. Their decomposition will release greenhouse gases. And a lot of them.
The Arctic’s permafrost today holds more than twice as much carbon as our atmosphere already contains, says Rose Cory, an assistant professor in the U-M Department of Earth and Environmental Sciences who leads the project that’s using the UV sensors. She is studying the role sunlight plays in how organic carbon decomposes.
Depending on how quickly that carbon is released, it could have a big warming impact.
At the same time, policymakers base carbon dioxide limits on climate models that don’t take permafrost thawing into account at all.
“Only recently have we gotten an estimate of how much carbon there is in permafrost. The knowledge hasn’t been incorporated yet,” says Ellen Dorrepaal, a plant ecologist at Umeå University in Sweden whose project Van Dam has also assisted with.
New studies from just this year have called attention to this. Thawing permafrost is projected to become a significant source of carbon in the atmosphere by 2100.
Standing Way Back
We live on a planet.
That’s how U-M associate professor Bassis responded when asked about the role the Arctic plays in the shifting climate. He wasn’t being facetious. Earth is a self-contained sphere, but that’s easy to forget if you’re not a climate researcher.
“We think of the Earth as a system, as this big complex system. The Arctic is one component of that system,” Van Dam says. “And all of us who’ve learned a bit about engineering understand that in general you can’t change one component of a system without having an impact on the entire system.”
That’s especially true when that changed component kicks off self-reinforcing loops, feedback cycles that knock the entire system out of equilibrium.
In addition to the planet’s mean temperature, carbon dioxide levels are spiking faster than ever before. At more than 400 parts per million today, the atmosphere holds more of the gas than at any point in known history. It likely holds more than it has since a warm period roughly three million years ago in a geological epoch known as the Pliocene. Then, says geologist Pollack, the seas may have been 100 feet higher, and shorelines 100 miles inland. All of Florida was likely under water. Scientists aren’t sure what brought about the Pliocene climate. While high carbon dioxide levels played a role, their cause is unclear. Changes in ocean and air currents likely contributed to the warmth, and its eventual end. Scientists believe it came to a close some 300,000 years after it started due to continental movement that shifted ocean and air currents.
“The overarching lesson of the Pliocene is sobering:” Pollack writes, “An ice-free Northern Hemisphere, with no sea ice covering the Arctic Ocean and no ice sheet on Greenland, is a possible condition of the modern climate system.”
Earth has been through something similar before. But humans haven’t.
“It’s not just climate change. We’re having an impact on our water, air and wilderness preservation,” Van Dam says. “All these things are related and extremely important. That gives me a great sense of responsibility to use my training in engineering and sciences to try and have a positive impact, not a negative one… And sometimes that sounds like bullshit, but most of the time I feel like it’s important to at least try.”