We all have our own ways of noticing changes in the climate. I’m a serious gardener. I spend the entire summer on gardening chores, and at the end I usually say, “I could use another month of that!” In the last couple of years, I haven’t needed to wish for a longer gardening season, as our autumns have been incredibly mild. Some of my friends wish for longer skiing seasons; others complain of the hot humid weather that summers have brought us. If we’re paying attention, we’re noticing climate change.
In this article I share the latest insights from experts on Minnesota’s natural resources to develop a picture of what is in store for us, and how we will need to adapt. For me it goes without saying that we should all do everything we can to reduce our activities that produce greenhouse gases, but it is clear that no matter what we do now, climate change is upon us.
The University of Minnesota Climate Adaptation Partnership (MCAP) provides the big picture:
“Minnesota is warming. The average annual temperature across the state has increased nearly 3℉ since the late 1800s, with Minnesota outpacing the average rate of warming globally. The warming has also accelerated in recent years, with the warming rate between 1980 and 2010 greater than between 1950 and 2010.” Winters aren’t as cold as they used to be. From 1944 to 1993, 44 out of 50 winters in Minnesota registered -40℉ at some point, but from 1995 to 2017, only 13 out of 22 winters got that cold. If we don’t curb greenhouse gas emissions, by the end of the century we’ll have two months less of snow on the ground.
The Partnership, which conducts research and educational programs, recently came out with a model that allows anyone to see future climate projections at the scale of 2.5 miles. That’s amazing.
I’ve never trusted models (I don’t understand them very well), but Dr. Suzi Clark, who helps run the Partnership, makes a convincing case.
“I’m confident in the models because they take fundamental understandings of physics and use those to project future climate,” she says. “They’re based on long-standing scientific principles that we understand to be true. Looking back at the models of the 1970s, we see now that they were remarkably accurate at predicting how the earth would respond to increased greenhouse gases.”
This new, fine-scale model is called MN CliMAT, the Minnesota Climate Mapping and Analysis Tool.
Researchers test climate models by having them “predict” past weather and then comparing the results with the actual climate record. The MN CliMAT group identified six models that worked well for the Midwest. “What we put into the tool is the average of all six,” says Clark. “The best practice is to average across different models to avoid skewing results.”
She says the biggest source of uncertainty is not in the models themselves but in the scenarios that are plugged into them.
“A lot of people expect models to ‘predict,’ but we carefully use the word ‘project.’ They give not a single number but a range of possible values and it’s up to us to understand what that means for society.”
Clark says the fine scale of the new model should help local decision-makers prepare for change. The high resolution permits simulation of extreme storms and interactions with nearby water bodies, and it offers a glimpse of how faster, smaller-scale processes like storms might change as a result of climate change.
The Partnership plans to offer workshops to explain how to use the tool, open to community leaders and the general public. The intent is that people who are trained in it can teach others. “We’re trying to get people to move from planning to action,” Clark says.
Of course, no tool is perfect. Dr. Mark Seeley, retired University of Minnesota climatologist and meteorologist who helped organize the Partnership, says many models overestimate summer warming. Some researchers theorize that this could be related to water vapor. “Our climate has gotten progressively wetter in summer, and it takes a lot of energy to evaporate that water before it can heat up the landscape,” he says. This could explain why summer temperatures aren’t reaching the models’ projections.
What do the models project and what do those projections mean for us?
Dr. Lucinda Johnson, recently retired Senior Research Fellow at the University of Minnesota Duluth’s Natural Resource Research Institute, studies rivers. She’s concerned about the cold-water streams that flow into Lake Superior from its north shore and those in southeastern Minnesota’s karst country. “Multiple stressors are hard on a system,” she says, “and with climate change there’s not just the temperature stress but the stress of the changing seasonality of the flow regime, impacts of multiple large storm events that sweep through, and those storm events seem to be followed or accompanied by subsequent drought events.” How can we help these streams? Johnson embraces a strategy of lessening other stressors to make streams more resilient. “Things like restoring riparian vegetation, wetlands, and fish populations,” she explains.
The Minnesota Department of Natural Resources says the state has experienced 19 “mega-rain” events since 1866, defined as six inches of rain covering more than a thousand square miles, with at least eight inches falling somewhere in that area. Of those 19, ten happened in the last 20 years.
One of those shocked people in northeastern Minnesota in June of 2012. Duluth got 7.24 inches of rain over two days, the St. Louis River rose to a historic crest of more than 16 feet, causing massive erosion, and western neighborhoods were evacuated. It took years to rebuild streets and other infrastructure, with a price tag of $47 million. At least three such “mega-rain” events have occurred since 2012 in central and southern Minnesota.
We amateurs use the term 100-year flood, but the scientific description of such an event is that a flood of that magnitude has a one percent chance of occurring in any given year, that is, the chance of it occurring this year is one in 100. According to the National Weather Service, the twenty-four hour rainfall at the Duluth Airport of 6.90 inches far exceeded the 100-year flood value, which is about 5.25 inches.
The big Lake
Lake Superior has a big impact on the weather of the lands around it, and the big Lake’s water is getting warmer faster than nearby land: so much so that blue-green algae blooms have been seen along its shores several times over the last decade. Jay Austin, Professor of Physics and Astronomy at UMD’s Swenson College of Science and Engineering, calls these sightings a “shot across the bow,” a warning of things to come. “They tend to occur in years of heavy rainfall,” he says, and scientists are looking at the many watersheds that line Lake Superior to understand what’s being flushed into the lake to get them going. Nutrients such as phosphorus are the usual culprit.
Austin warns that we’re “in the infancy” of understanding Lake Superior, and the system is so large and complex, we are limited in our ability to manage it. “We have to be prepared for it to change,” he says. He acknowledges that it will be a challenge since it’s part of what defines who we are, at least those of us who live near it. “For example, ice fishing is a big part of our culture here, and those big ice encampments off Leif Erickson Park that sprouted up a few years ago when the ice was so thick, those kinds of things will be increasingly rare.”
Scientists are also working to understand the longer-term patterns of change. Austin says 1998 was a pivotal year. “Prior to 1998 we saw lots of very high ice years (in terms of thickness, extent and season of cover) and we’ve seen very few of them since then; there were very few low ice years before that and lots of low ice years after that.” Researchers are recognizing climate change may not be a gradual, constant drift toward warmer conditions; it may occur in steps. But there’s no consensus on why.
Trying to keep the northwoods…
There seems to be increasing agreement about what’s likely to happen in the northwoods. Many experts expect the northern Minnesota forests to be confronted with warmer conditions, and, crucially, drier conditions during the growing season. Brian Palik, Science Leader for Applied Forest Ecology at the U.S. Forest Service’s Northern Research Station in Grand Rapids, says he expects summer rainfall to decline, which could spell hardship for trees and more damaging wildfires.
As most of us know, Minnesota lies at the convergence of four major biomes—aspen parklands, prairie grasslands, deciduous forest, and coniferous forest. Aspen parkland dips into northwestern Minnesota from Alberta, Saskatchewan, and Manitoba. Prairie grasslands once dominated the west central and southwestern part of the state. An arm of the great eastern deciduous forest reaches up through the center part of Minnesota. And the boreal species that blanket eastern Canada, like white spruce, black spruce, tamarack, red pine and jack pine maintain a toehold in northeastern Minnesota.
For some time, observers have noted the boreal species retreating northward, while deciduous trees such as oaks and maples creep up to replace them. But it’s happening slowly, and Palik says human-introduced barriers like roads, parking lots, agricultural fields, and suburban housing developments are getting in the way. Now foresters are embracing the idea of “assisted migration.” They plant seedlings selected from tree farms just to the south of the planting area. “We have moved tree species from southern Minnesota like white oak and bitternut hickory into northern pine forests,” he explains. “They’re doing exceptionally well, showing near 100% survival, and growing well. That tells us the climate is already suitable for them here.”
This change will prompt an adjustment in the forest industry, Palik says—but that’s happened before. In the days of towering white pines, aspen was considered a weed. But because it was so abundant, the industry found ways to use it, building pulp and paper mills and introducing particleboard.
One species of particular concern is black ash. Minnesota has more than a million acres of black ash, often growing in single-species wetland woods. As many as 95 percent of the trees in these wetlands can be black ash, a species that thrives by pumping water into its dense wood. The introduced Emerald ash borer (EAB) is expected to eliminate virtually all these trees in a short time on a scale seldom seen in nature. First found in Michigan in 2002, it has killed hundreds of millions of trees in North America, including in Minnesota, where it was first found in 2009. There is hope of slowing its spread through the use of insecticides and biological controls, but many ash stands are in remote areas that are difficult to treat.
Palik is researching what happens when the black ash stands are removed in one fell swoop, and it isn’t a pretty picture. “(The land) tends to turn into cattail sedge meadows that are wetter than they were, and it’s really hard for trees to get established in that kind of setting,” he says.
On the research plots, Palik has tried planting various types of seedlings, with mixed results. Cedar typically likes wet ground, but it’s a favorite food of deer. Swamp white oak, a wetland species from southeastern Minnesota, and balsam poplar can survive. But it’s hard to plant a million acres in the short time we have before EAB fells the ash.
NRRI research suggests conversion of these sites to open swamps will lead to significant shifts in animal populations. Some amphibians might benefit from the wetter conditions, but the study concludes, “the loss of forest canopy will result in an overall decrease in bird diversity and reduced forest connectivity for all species.”
.… and those who live there
Changes in temperatures bring changes in bird populations. Laura Erickson, author of many books and a popular podcast on birds, observes many of these. One of her favorite birds, the Canada jay, is having trouble reproducing. “Most of their diet is small animals, and to get through their frigid nesting season (late January and February), they squirrel away fat and meat in tree crevices,” she says. “They have powerful salivary glands that produce a kind of food preservative that works up to about 40 degrees Fahrenheit. With the increased numbers of thaws we’re having, it’s like when you go on vacation: when the power goes out for a few days, your food is spoiled. They’re directly impacted by mild winters in a very bad way.”
Researchers at NRRI are using sophisticated equipment to track bird movements, both in the northern woods and during their migrations. Wildlife ecologist Alexis Grinde is excited about how much more researchers can learn with such technologies as GPS, geolocators, and tiny radio transmitters. They have watched short-distance migrants like the Winter wren and the Brown creeper come back to their breeding grounds too early. “If it starts warming up in March or early April, everybody gets super-excited and begins their breeding activities, and then it snows again,” she says. “A small bird can get knocked back; some move back south and wait there, up to a month. So they’re spending a lot of energy thinking the weather is good and then having to leave the area. We’ve seen population declines in species that use that strategy.”
Snow: it’s like Earth is sleeping without a blanket.” —Mike Wiggins Jr.
Tribal communities are keeping track of environmental changes caused by a warming climate. The Great Lakes Indian Fish and Wildlife Commission (GLIFWC) represents eleven Ojibwe tribes in Minnesota, Wisconsin, and Michigan that reserved hunting, fishing, and gathering rights in 19th century treaties with the United States government. GLIFWC recently published “Aanji-bimaadiziimagak o’ow aki,” a vulnerability assessment for a set of beings living in the ceded territories, looking ahead to the mid-21st century. It includes projected impacts on the tribes’ cultural practices.
Findings include holistic descriptions of the varied impacts of warmer winters, such as:
“More precipitation falling as rain, reducing the snowpack, which is often critical for a slow release of water in the spring and for protecting beings such as miin (blueberry) from browse by waawaashkeshi (white-tailed deer), waabooz (snowshoe hare), and other plant-eating beings. It may also lead to more crusty snow conditions, which can make travel difficult for waawaashkeshi and hunting more difficult for gookooko’oo (owl) and waabizheshi (American marten)… Waabooz also depends heavily on snow for camouflage. Its fall molt from brown to white appears to be closely linked to photoperiod (the amount of light in a day) instead of snow cover, and waabooz is turning white around the same time in the winter, even as the snow season starts later. This makes it highly susceptible to predation by a variety of beings. Waabooz also depends on snow for food availability in the winter—a deeper snowpack allows it to reach more high-quality browse. Waabooz has already been observed to be in decline.”
The document also notes:
“Mooz (probably doesn’t need translation) struggles to regulate its internal body temperature when temperatures rise, which can result in changes in movement, poor nutrition, and increased sensitivity to parasites… increases in temperature and number of growing degree days are predicted to alter many fish communities in inland lakes by favoring warm-water beings (e.g., ashigan, largemouth bass) over cool- and cold-water beings (e.g., ogaa, walleye).”
Native people are also impacted by the big storms that have become more frequent. Not only are they expensive to recover from; they can be extremely destructive to wild rice, a staple of Ojibwe diets. Ricers may need to travel to distant lakes to collect the important food.
Collecting ziinzibaakwadwaaboo, maple sap, is also expected to be disrupted. “Spring nights below 32°F are extremely important… as freezing nights and thawing days allow ziinzibaakwadwaaboo to run. The timing of ziinzibaakwadwaaboo collection is becoming increasingly erratic, and in some years in which temperatures are especially warm and freeze-thaw cycles are irregular, tribal members are getting very little or even no ziinzibaakwadwaaboo at all.” Further, sugar content is expected to decline as temperatures warm.
Native artisans are worried about the supply of baapaagimaak, black ash, used for basketmaking, and aagimaak, white ash, used for snowshoes, lacrosse sticks, and other crafts. These trees are increasingly vulnerable to the Emerald ash borer, whose larvae typically perish in the extremely cold temperatures that are already less frequent.
On the brighter side, the document suggests climate change may provide “an opportunity to return to the relationship with ishkode, fire, that Ojibwe people have long held, which has been demonstrated to reduce the conditions that lead to uncontrolled fire, and to be helpful in the restoration of culturally important landscapes and beings… cultural burning of land areas to promote certain beings or habitats was a part of Ojibwe stewardship for thousands of years.”
We are all seeing and feeling these changes, for good and for ill. In my garden I can now grow sweet corn, melons, and other warm season crops. Perhaps I should learn to dry the harvest instead of freezing it. We have solar panels, but some of our electricity still comes from coal-fired power plants that contribute to the climate disruption we are all experiencing. I know we’re not alone in taking stock, trying to see where we can lessen our own contributions to climate change and make for a better future. As Lucinda Johnson says, “We gotta quicken the pace.”