How Climate Change Will Impact Minnesota

Ready for a Minnesota that's hot, wet, and smells like cilantro? Here's what the future holds for our wild places–and your backyard.

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For a few decades now—yes, it’s been a while—we’ve been hearing about what a warming Earth will look like in the future. Wildfires in Los Angeles. Flooding in Miami. While we were looking elsewhere—or trying to cover our eyes—Minnesota became the second-fastest warming state in the country. For better or worse (probably worse), we’re starting to see how it will play out. The pine forests will swoon. Some of our iconic animals—moose, lynx, loons—will move up north . . . to Canada. Our basements will flood. And we won’t want to sleep with the windows open in August. What will climate change look like in Minnesota? Here’s a snapshot.

Imagine that you could hop into a time machine and travel back 120 years to pay a visit to that most iconic of Minnesota’s locales, the Gunflint Trail. What sort of large, charismatic animals might you encounter?

A moose seems like a good guess.

And that guess would be wrong. At the turn of the 20th century, the most common member of the deer clan in far northeastern Minnesota was not the moose. Nor, surprisingly, was it the now-ubiquitous white-tailed deer—a rarity then (!) in most forested parts of the state. In the north country of yesteryear, the king of the hoofed mammals was the woodland caribou, wild kin of the old-world reindeer.

Human intrusions into the caribou’s domain proved to be its undoing. Logging, road building, and wildfires eliminated the caribou’s preferred habitat: large, unbroken tracts of old-growth woodlands. Those same changes to the landscape benefited moose and deer, which favor younger, more fragmented forests. The increased numbers of moose and deer became a boon to the timber wolf. 

And that, in turn, proved to be a calamity for the woodland caribou. Despite an astonishing capacity to survive in the bleakest environments, caribou fail pitifully at defending their young from wolves.

By the 1940s, the shy lichen-eaters had mostly disappeared from Minnesota, their existence memorialized in a few place names and otherwise mostly forgotten. Over the years, stragglers have wandered down the North Shore from Canada during winters. But with the entire Lake Superior herd on the brink of collapse, it’s been decades since we got a cameo.

When we hear about global warming—or block our ears and try not to hear about it—we tend to think of systemic changes. Cataclysmic stuff. Floods and droughts. Heat waves and hurricanes. Death from above. It’s probably rational—even productive—to worry about that stuff.

But the example of the caribou demonstrates something else. That is, we’ll see what climate change looks like when we walk in the woods—or walk down the sidewalk. We’ll see animals come (are you ready for feral pigs?) and go (goodbye, moose). Pine forests will become oak and maple woods. All the ash trees will die. 

Climate change is, in the strict sense, a matter of degrees. Minimums and maximums. A few here, a few there. But we’ll see it play out in more absolute terms. One summer, sitting on the dock at the cabin, we’ll realize the loons have left the lake. And we’ll never see them there again. 

As large mammals go, humans may not be the most observant creatures. But if the changes wrought by the last 120 years seem dramatic, you ain’t seen nothing yet.

You don't need a weatherman...

But you do need a climatologist to keep track of the unbelievable changes happening outside. Here’s what it looks like, by the numbers:

Pushing the Boundary

Looking for the Bold North? Try Canada.

Many lovers of the Boundary Waters Canoe Area Wilderness express horror that mining companies may be allowed to tap the huge copper and nickel deposits at the edge of the wilderness. But if mining poses an immediate threat to the BWCA, climate change poses the existential one.

When Lee Frelich, director of the Center for Forest Ecology, at the University of Minnesota, testified before the state legislature about the effects of climate change on the BWCA, he called Minnesota “the edgiest state in the nation.” That’s because Minnesota sits at the edge of four (or five!) major biomes: that is, systems of interrelated plant and animal communities. 

The biome that reaches into the BWCA is the boreal. Yet this familiar mix of spruces, firs, aspen, pines, and birches exists just at the southern extreme of the boreal. That renders it more vulnerable to swings in temperature and precipitation than any other part of the state.

The flora and fauna here—think of the moose in the deep woods—represent the image Minnesota sells on postcards and calendars. In a few decades, though, you’ll want to send that postcard from someplace farther north: Ontario. 

Pray for rain?

The prairie/forest boundary in Minnesota depends on rainfall. Regions that are net-dry become prairie, while net-wet regions remain forested. But even if total precipitation increases in the future, the scale could tip from an expected rise in hotter, drier late-summer weather. The effect might be the savanna-fication of the region, especially in the western portions of the BWCA. According to Frelich, the prairie/forest boundary could move approximately 300 miles to the northeast by the end of the century. How fast and how far will be dictated by global greenhouse gas emissions.

Mean summer temperature is a key tipping point.

What difference can a few degrees make? In northeastern Minnesota, firs and spruces tend do better if the mean summertime temperature stays at 63 ⁰F or below. When that mean summertime temperature reaches 66 ⁰F, maples, oaks, and other deciduous trees take over. In recent years, Duluth has crossed this meteorological rubicon. Now, the shift in forest composition is starting to show up in the BWCA.

Hot springs?  

Who doesn’t love an 80-degree day in March? A boreal forest. In March 2012, the BWCA experienced one such anomalous temperature spike. The result: a “winter browning” event that killed off vast stands of spruce trees in Minnesota and southern Ontario.

Subtract 1 million acres of pine forest.

The mountain pine beetle may be the most destructive insect blight to strike North America’s forests. In the western U.S. and Canada, the beetles have killed so many lodgepole pines that those battered forests can no longer act as a carbon sink. Instead, they’ve become a net contributor of greenhouse gas emissions. What has protected Minnesota’s pines? So far, geography. But the beetle’s spread into the boreal forests of Alberta raises fears that it could work its way into Minnesota. According to Frelich, wintertime lows of minus 40 ⁰F suppress the beetle population. But that type of weather will likely become rare.

Picture Minnesota without its tamaracks. 

Beguiling trees that look like conifers (except the needles turn yellow in fall), tamaracks once stood out as the most common tree in Minnesota. Prized for their long, straight trunks—good for telephone poles and railroad ties—they provided an important source of timber. Now the tamaracks are experiencing an unprecedented die-off. The cause: an extreme outbreak of a native pest, the Eastern larch beetle. The larch beetle’s population explosion appears to offer a flashing sign of climate change.

The worm has turned.

A simple maxim: Fish love worms, and therefore fishermen love worms. But all earthworms are invasive to Minnesota. Ecologists worry about their presence in northern forests because worms destroy the duff: the layer of leaf litter and decaying organic matter on the forest floor that many native plants need to successfully regenerate. 

Worms now live throughout the BWCA. Anglers present the sole explanation for their presence.

Yes, we’ll miss the frigid winters.

To date, most of Minnesota’s documented warming has occurred in winter. Those cold January nights aren’t as cold as they once were. While that sounds like good news, our extreme winter lows have traditionally afforded the state’s forests protection from some of the worst insect pests.

Arrivals and Departures

Goodbye moose, goodbye loon. Hello... feral pig? 

You’ll miss me when I’m gone. If the native fauna of Minnesota could speak, more than one creature might offer that curse. Many once-common species are staggering from a loss of habitat, a warming climate, and the emergence of invasive species. Meanwhile, plenty of arrivistes—welcome or not—are staking a claim to new territory. Say farewell to some dear old friends, and meet the new neighbors.

Arrivals

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Bobcat

Illustration by Emily Krueger

Bobcat

Boom times for bobcats! Scientists number the Minnesota population between 5,000 and 7,000—an almost three-fold increase from just a few decades back. Why? Bobcats are highly adaptable creatures and, in the absence of unregulated hunting and trapping, they can survive in varied environments. Bobcats inhabit every state in the lower 48 (except Delaware). In Minnesota, bobcats have moved into the boreal forest of the Arrowhead. They are also starting to recolonize southern Minnesota after a long absence. Minnesota felines enjoy one advantage over their counterparts from western states: Their pelts look duller, which means they fetch less on the fur market.

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Possum

Illustration by Emily Krueger

Possum

With a pointy snout, a rat-like tail, and a set of 50 sharp teeth, the Virginia opossum disgusts many people. Too bad, because these nocturnal omnivores perform some valuable services, preying on rats and mice and, vulture-like, consuming carrion whole. Fastidious self-groomers, they hoover up prodigious numbers of ticks. Our only native marsupial has occupied the southeastern corner of the state for at least a century. More recently, possums have turned up in unexpected places like Duluth and Bemidji. The territorial expansion stretches back 3 million years, when a land bridge in Panama permitted the possum’s ancestors to trudge north. Humans have played a role, too. Transplanted Southerners likely brought live possum to California for culinary purposes. Don’t scoff, foodie: The 1962 edition of Joy of Cooking contains a possum recipe.

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Feral Pig

Illustration by Emily Krueger

Feral Pig

This voracious omnivore has been known to eat everything from row crops to vegetables to baby deer. Truly, the hog earns its reputation as the country’s most destructive invasive land animal. Nationally, wild pigs inflict an estimated $2.5 billion in annual agricultural damages. And milder winters may provide more forage, sustaining animals and encouraging population growth. With sows capable of producing two litters (of six piglets) each year, they don’t need much help. At present, Minnesota remains one of 11 states without free-ranging swine. But these descendants of domestic pigs—some of whom later hybridized with Russian wild boars—are on the march. The population moves north at a rate of seven miles a year, according to the United States Department of Agriculture. So far, the animals have colonized all of Michigan and parts of Wisconsin, Iowa, and North Dakota.

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White-Tailed Deer

Illustration by Emily Krueger

White-Tailed Deer

It’s long been understood that deer appreciate many of the things humans do to landscapes. Logging an old-growth forest? Deer love it. Planting suburban garden plots? Ditto. But in Minnesota, deer are also beneficiaries of how we have changed the composition of the atmosphere. In northern forests, the warming climate is producing more maples and oaks (favorite menu items for deer) while disadvantaging firs and spruces (low-value foods/climate-change losers). Deer mortality is strongly associated with winter severity, so shorter, milder winters also boost their numbers. The X factor: Will the herd get knocked back by chronic wasting disease? Minnesota has experienced only isolated incidents of the contagious and always-fatal plague. But in neighboring Wisconsin, wildlife managers have been unable to control an outbreak, and the disease is now endemic.

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Asian Longhorned Tick

Illustration by Emily Krueger

Asian Longhorned Tick

This newcomer to the U.S. hasn’t shown up in Minnesota yet. But since 2017, when scientists first detected it in New Jersey, the nasty parasite has turned up in eight other states. (Ticks prefer the kinds of temperate and humid conditions we’re likely to see in the future.) The Asian longhorned tick is an effective transmitter of numerous pathogens that can sicken both people and livestock. In New Zealand and Australia, the tick gets blamed for a 25 percent reduction in the productivity of dairy cattle.

Departures

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Loon

Illustration by Emily Krueger

Loon

Is there a sound more evocative of the lake country than the mournful wail of the loon? Possibly the roar of a jet ski. So beloved is this waterfowl that the National Loon Center Foundation is pursuing plans to erect a $10 million complex near Brainerd. (Critics call it the “loondoggle.”) Do loons really need our help? According to the Minnesota Department of Natural Resources, Minnesota holds more loons—approximately 12,000 adults—than any other state save Alaska. The population is currently stable. But long-term warming trends suggest a shifting habitat and a grim future. “It looks all but certain that Minnesota will lose its iconic loons in summer by the end of the century,” warns Audubon Minnesota.

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Native Mussels

Illustration by Emily Krueger

Native Mussels

The spread of zebra mussels in Minnesota waters has unfolded rapidly since the tiny but prolific filter feeders first appeared in Lake Superior. Regular announcements of new infestations elicit dread among anglers. But in ecological terms, the zebes’ most pernicious impact is not on fish but on native mussels. Currently, 13 species of Minnesota mussels—colorfully named denizens of depths such as the purple wartyback and the winged mapleleaf—are listed as endangered. That’s the most of any animal group in Minnesota.

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Canada Lynx

Illustration by Emily Krueger

Canada Lynx

Ever glimpse a lynx in the wilds of Minnesota? You’re lucky or a liar. Not that long ago, debate raged over whether the state even hosted a resident population, with some experts attributing the occasional sighting to vagrants from Canada. Now the prospects for Minnesota’s lynx appear shakier still. Current guesstimates place the resident population between 50 and 250 animals. Far more specialized than the bobcat, the large-footed lynx hunt best in deep snow. Their favorite prey, the snowshoe hare, has always followed cyclical booms and busts, but its numbers have declined steadily since the 1980s. More bad news for the lynx: Minnesota can claim the first documented cases of the endangered felines hybridizing with bobcats: an offspring called “blynx.”

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Piping Plover

Illustration by Emily Krueger

Piping Plover

Like most humans, this stocky bird loves wide, empty beaches. The plover builds its nest on the ground just above the high-water mark, rendering its chicks vulnerable to heavy rains and big winds—conditions we now see more often. Well camouflaged, piping plovers can be hard to spot as they skitter about the shoreline. A bigger reason you’ll rarely see one? The piping plover probably stands as Minnesota’s most endangered bird. In the 1980s, a small population nested on some dredge spoils in the Duluth harbor, but those birds have vanished. In 2011, birders spotted a single breeding pair at Lake of the Woods.

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Moose

Illustration by Emily Krueger

Moose

Are the moose of Minnesota doomed? Probably. By the late 1990s, the once robust herd in the northwestern region had dwindled to near oblivion. And since the mid-2000s, moose numbers have plunged in their northeast stronghold. The DNR’s current population estimate—about 4,000 animals—amounts to half the 2006 count. Thermal stress poses one problem. Moose aren’t built for summer: They start panting once it hits 68 ⁰F. Other threats include growing numbers of winter ticks (which proliferate in a milder climate) and territorial invasions from white-tailed deer. These creatures carry a parasitic brain worm that is fatal to moose. The combined result: a greater vulnerability to wolves.

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Poweshiek Skipperling

Illustration by Emily Krueger

Poweshiek Skipperling

Just a few decades back, these orange-and-brown butterflies commonly dotted Minnesota’s tall grass prairies. Current remaining population: likely fewer than 500, with the possibility of zero in Minnesota. The Poweshiek appeared on the federal endangered species list in 2014. Conservationists implicate the usual suspects, habitat loss and dirty agricultural practices. Of the 15 endangered or threatened butterfly species in Minnesota, 10 are denizens of farm country.

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Tullibee

Illustration by Emily Krueger

Tullibee

A small, silvery fish also referred to as cisco or lake herring, the tullibee has been described as “a cheeseburger with fins.” The appellation comes from the caloric value these oily, high-fat salmonids offer. Muskie and walleye love to fatten up on tullibees. Over the last 30 years, tullibee populations have declined by an estimated 60 percent across Minnesota. (They’re currently established in some 650 lakes.) One reason: The tullibee is a cold-loving fish that seeks refuge in deep water during hot summer months. But when a lake receives excessive runoff and then warms, algae blooms sink to the bottom and decay. That depletes oxygen levels in the deep, which forces tullibees into the warm surface waters. They often perish in mass die-offs from oxythermal stress. Other cold-water fishes facing similar perils include lake trout and whitefish.

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Connecticut Warbler

Illustration by Emily Krueger

Connecticut Warbler

Despite the Yankee nickname, this large and secretive warbler breeds only in Canada and a relatively small portion of the upper Midwest, a region that includes the black-spruce bogs of north-central and northeastern Minnesota. It’s an area that’s now subject to more pervasive pests. Conservationists have sounded alarms over a steep population decline since the mid–1960s.

Look Out the Window

In the future, your backyard will likely get muddier and weedier. And the basement will smell like a gym sock. 

The coming disruptions to Minnesota’s ecosystems won’t just happen out there in nature. They will occur in your backyard, in the park down the street, and in neighborhoods all across the metro. Are you ready for a proliferation of insect pests, damaging weeds, regular floods, and sweaty nights? Climate trends suggest we city folk face a future that will be hotter, wetter, and less shaded than the present.  

Shade is overrated?

During hot spells, the core of Minneapolis often stays 4 degrees warmer than outlying areas. The urban-heat-island effect will intensify with the loss of tree cover. By mid-century, southern Minnesota can expect 15 to 20 additional days with temps above 90 ⁰F. 

Weeds will win.

They call Japanese knotweed the “Godzilla weed” because it’s so difficult to kill. In Duluth, this invasive perennial grows in bamboo-like thickets along the shores of creeks. Originally planted as an ornamental, the plant spreads aggressively through vast root systems. Invasive plants thrive in disrupted ecosystems: In Japan, knotweed is often the first plant to colonize lava flows. That tenacity explains its tendency to break through sidewalks and building foundations. Houseplant, anyone?

Raking will be easier! 

After the last glaciers retreated from Minnesota, one of the first trees to emerge was the black ash. At present, ash (black, green, or white) grow in all of Minnesota’s 87 counties and account for around 9 percent of the state’s trees. Sadly, the ash’s run here is about to hit what looks like an extinction-level event: the arrival of the emerald ash borer. Severe cold spells kill off the pupae—but those weather events are becoming less frequent.

Rain boots are chic!

In late March, the Mississippi River at St. Paul hit an elevation of 20.19 feet, the seventh-highest crest on record. Then something even stranger happened: The river remained at flood stage for 42 consecutive days. Projections suggest that intense rainfall events and flash floods will become 45 percent more prevalent across the state by mid-century. Recommendations for homeowners: Shop for flood insurance and replace your sump pump.

Bogscape your lawn! 

The loss of all those mature ash trees means that more of the rain that falls on cities won’t be absorbed by the landscape. All that extra water—one estimate puts the volume at 1.7 billion gallons—will drain into urban rivers and lakes, fueling larger algae blooms and fish die-offs. (Thank your lawn fertilizer for that, too.) 

Like the smell of dirty socks?

This olfactory horror comes your way via the brown marmorated stink bug, a voracious agricultural pest first detected here in 2010. It takes about a decade for the BMSB to become firmly established, so Minnesota appears to be on the verge of a full-fledged invasion. (The BMSB arrived in the U.S. two decades ago—probably in a shipping container from China.

Warming temperatures tend to boost insect activity and reproduction.) In the mid-Atlantic region, the pest has devastated apple orchards. But it eats practically anything. For city folk, the BMSB presents a nightmare because it likes to overwinter, in huge numbers, inside manmade shelters. Such as your home.

"The Data Scare Me"

What's it like to spend a long career watching the climate go crazy - and the state legislature do nothing? 

For more than two decades, Minnesota weather guru Mark Seeley has been a staple of Minnesota Public Radio’s morning programming, where his folksy delivery comes across as reassuring, even as he delivers the bad news about a tornado or blizzard. But Seeley, professor emeritus at the University of Minnesota’s Department of Soil, Water, and Climate, is decidedly un-reassuring on the topic closest to his heart: our rapidly changing climate. As the self-professed “caretaker of the Minnesota climate database for 40 years,” Seeley knows better than most the particulars of those changes. As he tells Mpls.St.Paul, he worries about what he sees in the numbers.

When did it become evident to you that Minnesota was warming? I didn’t see it in our data until the early ’90s. That’s when we started to get some measurements from around the state that didn’t make sense in a historical context.

You have said that Minnesota set a huge number of weather records between 2006 and 2015. What’s the context? Around 2012, the Minnesota Historical Society asked if I’d write an updated edition of the Minnesota Weather Almanac. I was startled to learn that in the decade between edition one and edition two, our Minnesota-climate-observer network had recorded over 17,000 new daily records. We also recorded something like 150 statewide records. In other words, we were measuring some things that had never been measured in the history of the state. It is evidence that Minnesota is one of the places in the U.S. that is seeing some of the most prolific climate change.

How many weather records are set in a “normal” decade? There is a lot of fluctuation, but less than 10,000. During the 1990s, we set a lot of records because it was the wettest decade in Minnesota history.

It’s been pretty rainy this year. Is that wettest-decade record going to survive?  We haven’t finished the current decade, but the preliminary data suggest that the decade of 2011 to 2020 will surpass the 1990s as the wettest. It will also be the warmest decade in Minnesota history.

"We haven’t finished the current decade, but the preliminary data suggest that the decade of 2011 to 2020 will surpass the 1990s as the wettest. It will also be the warmest decade in Minnesota history."

Last winter, we had some of the coldest weather in more than two decades. Does that make it harder for people like you to get your message across? That gets to the difficulty of deciphering signal from noise. The statistical noise level—or background variability—is so magnificent in a place like Minnesota that we can still have aberrations like the winter and spring of 2013, when we saw some of the latest ice-out dates in history. That’s one thing I’ve tried to coach our local leaders: We might have a winter with 100 inches of snow or a minus-56-degree day, like we had in Cotton this winter. Those things are still going to happen.

Right before that cold day in Cotton, you and several other experts from the U of M testified about climate change at the Capitol. Did that lead to any concrete action? I have 40 years of frustration in front of the Minnesota legislature. My batting average is pretty poor, even though I try to use data and evidence to make my points. The Republican caucus, quite frankly, is pretty firm in not wanting to do much about climate change.

Most of Minnesota’s warming has occurred in winter. When will our summers heat up? I don’t know the answer. What we’re seeing now fits well with the models that say in the mid-to-high latitudes, overnight minimum temperatures are going to change faster than the maximum temperatures. And, further, the season of long nights and short days is going to have more amplitude of change than the summer.

Climate change is a depressing subject. Are you pessimistic about the future? I try to be realistic. I’m not trying to be optimistic or pessimistic. My experience at the University of Minnesota gives me some hope, because I see so many smart young people going into environmental science. They’re thinking about this more seriously than my generation did.

But quite frankly, the data scare me. Look at last year’s numbers in Fillmore County, where we had weather observers recording more than 60 inches of precipitation. That’s Tallahassee, Florida. That’s not Minnesota. 

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