How could climate change affect Minnesota? Study offers details

Minnesota’s winters are getting warmer and wetter, and are likely to get even more so. What is now snowfall will more often be rainfall. And those dreaming of a white Christmas will probably have to be satisfied with pictures from the past.

Such may be the effects of climate change, according to a new University of Minnesota study presented to the House Climate and Energy Finance and Policy Committee on Monday. The study provides projections of what the middle and end of the 21st century may look like in various parts of the state if greenhouse gas emissions are lowered to levels recommended by the United Nations Intergovernmental Panel on Climate Change or if they’re not.

Speaking of that U.N. panel, the chief author of its latest report – the fourth in a series – was among the testifiers at Monday’s hearing.

Stephanie Roe offered more of a global perspective on what actions could be taken and how much of a difference they may make and how soon. But she also addressed questions about what Minnesota may be able to do to escape the fate laid out in the direst scenarios.

“We’re going to see continued warming in winter,” said Tracy Twine, a University of Minnesota professor in the Department of Soil, Water and Climate, who was co-author of “Minnesota’s Climate at the End of the 21st Century.” “But we’ll also see an increase in summer warming. There will be fewer days with snow on the ground. … But these can be mitigated with reductions in greenhouse gas emissions.”

The study concluded that the northern third of the state has seen the most significant rise in winter average low temperatures — 7 degrees Fahrenheit higher in 2019 than in 1895 — and that trend is projected to continue, especially without a reduction in greenhouse gas emissions. Twine said that, with no mitigation, average annual temperatures are likely to be 10 degrees higher by the end of the century.

The rise in summer temperatures is projected to be not as significant, but still substantial, about 7 degrees higher with no mitigation, 4 degrees if the IPCC’s recommendations are followed.

As for precipitation, the study concluded that, without reductions in emissions:

• the state will be wetter every month expect July;
• average annual snow depth will decrease 5 inches in the central part of the state; and
• the state will see 55 to 60 fewer days a year with snow cover.

As for the global perspective, Roe outlined conclusions in the latest Intergovernmental Panel on Climate Change report, which was compiled from over 18,000 scientific papers compiled by 278 authors from 65 countries.

Among the report’s most significant findings are:

• greenhouse gas emissions are at their highest level in human history;
• while they slowed in energy and industry, they’ve increased in the transportation sector;
• limiting warming to the Paris Agreement goal of 1.5 degrees Celsius would require global greenhouse gas emissions to peak before 2025, and be reduced by 43% by 2030; and
• to reach the goal, methane emissions must be reduced by 34% by 2030.

In answer to questions from Rep. Todd Lippert (DFL-Northfield) and Rep. Athena Hollins (DFL-St. Paul), Roe discussed potential changes in both rural and urban settings that could mitigate greenhouse gas emissions.

“Enhancing forests and peatlands has great potential for carbon reduction,” Roe said. “Peatlands are one of the most carbon-dense ecosystems on the planet. … As for croplands, emissions arise primarily from synthetic fertilizers in cultivated soils.

“And there’s great potential in mitigating more in urban areas by increasing green spaces and adding trees to cities.”