The Crossroads of Climate Change
–Kathleen Weflen, Editor-in-chief, Minnesota Conservation
Sitting at a polished wood table, testifying before a legislative committee, the University of Minnesota Regents Professor was doing her best to explain the cascade of consequences likely to befall Minnesota’s environment and natural resources as the climate warms. Committee members stirred in their seats; some checked their watches. Finally, leaning forward and raising her voice a bit, she said, “Look. What I’m trying to say is this: If I wanted to live in Nebraska, I’d move there.”
Within the next century, temperature readings in Minnesota could climb enough to match the readings in Nebraska today. If our weather also becomes as dry as the central Great Plains, our trees will begin to die.
Eventually, semiarid grasslands and oak savannas will replace our forests from south to north, and Minnesota will look a lot like Nebraska.
This is one possible scenario based on global warming. If this reshaped landscape doesn’t come to pass, another will. Climate data, past evidence of climate change, and future models point to the inevitability of grand-scale, climate-related alterations to our lands and waters. Indeed, the entire planet is about to be re-landscaped.
During the past two decades, most springs in Minnesota have arrived earlier than usual – sometimes by a week or more. Eight of the 20 warmest years in Minnesota have been recorded since 1981. While the mid-1990s brought some unusually harsh winters, never in recorded history has Minnesota had three benign winters in a row as it did with record high-temperature years occurring in 1997, 1998 and 1999. One question on our minds: How will our state change if spring comes earlier every year?
Winners and Losers
For some wildlife populations, the changing climate would be not all bad. White-tailed deer, for example, would not be perturbed if Minnesota looked like Nebraska. They can find food and shelter just about anywhere – from boreal forests to southern grasslands. Pheasants and wild turkeys, also at the northern edge of their range in Minnesota, could multiply too. As grasslands expand, Minnesota might attract more meadowlarks, field sparrows and the like. Painted buntings, great-tailed grackles, and a few other species could colonize the state.
On the other hand, species adapted to specific habitats would be more vulnerable and more likely to shift locations. The disappearance of boreal forests would dislocate boreal species such as pine marten and fisher. And, unlike whitetails, moose cannot tolerate heat and need boreal vegetation to survive. Their range would shift northward, out of Minnesota, as would that of pine siskins, boreal chickadees and other north-woods species. Dark-eyed juncos and evening grosbeaks would no longer turn up at Minnesota bird feeders. And it may be no use listening for the songs of white-throated sparrows or a host of now-native vireos and warblers.
Few ducks may answer the calls of hunters in western Minnesota’s prairie potholes, part of North America’s most important waterfowl breeding area. Hunters hoping to head north to find ducks in Canada might be sorely disappointed: ducks breeding farther north may be less productive, and wetlands there may also suffer drought. A few dozen more birds might move into newly suitable habitat as their former ranges shift.
Lake and stream temperatures may change too. Eventually, even the groundwater – fed streams of the southeast could warm. Along the Superior North Shore, dense canopies of spruce create cool microclimates along the streams. If Minneapolis’ weather moves up the North Shore and spruce decline, all of these streams would likely lose their trout and other species that are dependent on current temperatures.
Why Act Now?
“The earth’s temperature will continue to rise even if we stabilize carbon dioxide emissions today,” says Peter Ciborowski, the Minnesota Pollution Control Agency’s expert on climate change. “That’s because we’ll still be adding 3 to 4 billion metric tons of carbon per year to the atmosphere.”
Research ecologist John Pastor insists that people need to view both the causes and consequences of warming in personal terms. How we use our land, cities, and highways affects the climate as surely as the climate affects us. If we drive fuel-efficient cars and reduce our annual mileage, for example, we keep tons of carbon out of the atmosphere.
Humans might be able to adapt to new habitat in a warmer world, but what are we willing to give up? “At risk is our natural heritage,” Pastor says, “our sense of place.” And we could lose that identity soon, unless we each begin to act now.