State known for hockey and ice fishing is feeling the heat

Source: Daniel Cusick, E&E News reporter • Posted: Tuesday, January 22, 2019

ST. PAUL, Minn. — The U.S. state most synonymous with winter cold is getting warmer every day.

Scientists representing a variety of disciplines — climatologists, ecologists, agronomists, economists and public health experts — warned in a series of legislative hearings this week that Minnesota must prepare for what could be a dramatically warmer climate by the end of this century.

The North Star State, which this time of year celebrates pond hockey, ice fishing, winter carnivals and temperature-controlled skyways linking downtown office towers, is now among the fastest-warming in the country.

Its primary cities — Minneapolis-St. Paul, Duluth and Rochester — are also rapidly warming, a condition reflected by milder winters and the urban heat island effect, said Bonnie Keeler, an assistant professor of public affairs at the University of Minnesota’s Humphrey School of Public Affairs.

This month alone, the Twin Cities have seen 10 January days with highs of 32 degrees Fahrenheit or above, while nighttime lows have yet to dip below zero. Average January temperatures are running 7 F above average statewide, according to the Minnesota Department of Natural Resources.

Even northern Minnesotans are feeling the relative heat.

“Overall, Minnesota is getting warmer and wetter everywhere and in every season,” Tracy Twine, an associate professor in the University of Minnesota’s Department of Soil, Water and Climate, told the state House Energy and Climate Committee, which is holding the series of state-focused climate change hearings into next week.

Summer in the north will also be hotter. Climate models project Minnesota will see between five and 10 additional days where the mercury rises above 95 F, and summer nighttime low in the 60s and low 70s will become more rare, resulting in increased demand for air conditioning and more heat stress for individuals who are active outdoors.

Vishnu Laalitha Surapaneni, an internal medicine physician and expert on warming’s effects on public health, said Minnesotans could see a rise in allergens such as ragweed pollen, while stagnant summertime air masses trap air pollutants close to the ground, worsening asthma and other respiratory diseases.

Unless something is done to reduce global greenhouse gases, children born to Minnesota families in 2020 will likely die in a place that looks and feels like Kansas, said Lee Frelich, director of the university’s Center for Forest Ecology and a national expert on ecological changes rendered by climate warming.

“Minnesota is in a very unique position on the planet,” Frelich said. “We have three distinct biomes that intersect within our state’s boundaries, and they are all responding to warming in different ways.”

‘Asking even more of them’

By virtue of its unique geology, Minnesota is also one of the most economically diverse states in the Midwest.

Corn and soybean farms dominate the state’s southern tier, while forestry, mining and wilderness recreation are mainstays of the state’s “arrowhead” region near Lake Superior.

The state’s western counties are seeing more row crop and livestock farms converted to wind farms, while its cities continue to draw people and jobs from other states and regions. Minneapolis-St. Paul, with roughly 3.6 million people, is on track to become the Midwest’s second-largest economy over the next decade, edging Detroit.

But additional warming caused by rising greenhouse gas emissions, especially under business-as-usual scenarios, could zap Minnesota’s economic muscle and tear its traditionally tight social fabric.

Like other states, Minnesota has seen sharpening political divides between its urban and rural populations. Farmers and other rural Minnesotans attribute much of the state’s greenhouse gas problem to the Twin Cities, where traffic, construction, and the heating and cooling of buildings make it difficult to hold emissions in check.

But farmers also play an important role in climate change. Agricultural practices like soil tilling, crop rotation and livestock management have their own emissions profiles, experts say. Some farmers have been slow to embrace methods that could reduce methane and nitrous oxide emissions.

Farmers also face extraordinary risks from climate change, as rising variability in temperature and precipitation makes crops and livestock more vulnerable to droughts, storms and pests.

Jessica Gutknecht, a soil ecologist and assistant professor of soil, water and climate at the University of Minnesota, noted that 2018 was one of the wettest years on record for the state’s farmers. It was also one of Minnesota’s worst years for corn rot, a disease that decreases crop yield and reduces grain quality.

Rising temperatures and longer growing seasons, often cited as a climate change benefit to Minnesota farmers, also come with some major downsides. “If our winters are warm enough, the eggs of some of our common pests will not die,” Gutknecht said, fostering the spread of damaging insects like corn rootworm and soybean aphids.

“Our farmers already face major challenges,” Gutknecht said. “We’re going to be asking even more of them as the climate warms, and some of the climate scenarios for Minnesota will make it even tougher for them.”

In northern Minnesota, scientists project that cold-dependent species — like spruce and fir trees as well as moose and lynx — will see their habitat shrink as plants and animals associated with warmer climates migrate into what was once pristine boreal forest.

“There’s already a major invasion of maple and oak [trees] into the boreal forest,” Frelich said. “It’s a different forest than it was 40 years ago. The warming that’s already occurred has had a big impact.”