FARGO — The winters will gradually keep getting shorter. The summers will get hotter. Droughts will become longer and more frequent. River flooding will increase.
Those are among the climate predictions for the region including North Dakota and Minnesota in the latest assessment of climate change science by the influential Intergovernmental Panel on Climate Change.
The panel’s report issued on Monday, Aug. 9, concluded that continued warming of the globe’s temperatures now is inevitable — and made the sobering determination that some changes might be irreversible.
For the region that includes Minnesota and North Dakota, the report predicts more extreme precipitation events are very likely as climate change continues to unfold. Winters, although they have gotten slightly warmer, are expected with medium confidence to get wetter.
At the same time, the increasingly volatile climate in the years and decades ahead also will produce increasing drought and fire weather in central North America, a prediction the report made with medium confidence.
“It really shows how what we’re seeing in Minnesota fits within a larger picture,” placing regional climate changes within a global context, said Kenneth Blumenfeld, senior climatologist for Minnesota’s State Climatological Office.
Those changes in climate will stem from an expected increase in average temperatures of 2 degrees Celsius, equal to 3.6 degrees Fahrenheit, the temperature rise predicted in the report for central North America.
Increased river flooding is expected even though winters are gradually warming, resulting in a shorter time to accumulate deep snowpacks, although spring flooding still will happen, he said.
Despite “a narrowing of the window when you can have a lot of snow on the ground,” floods will continue because snowstorms will continue to increase, Blumenfeld said.
“We’ll still get lots of snow,” he said.
Winter temperatures in Fargo have warmed overall by 2 degrees over the past century, but most don’t notice the warming trend because nights have increased 3 degrees, while daytime temperatures have increased only by 1 degree, said John Wheeler, WDAY StormTracker chief meteorologist.
The predictions are general and variations still will occur with fluctuations in temperatures and precipitation, Wheeler and Blumenfeld said.
In Minnesota, the northwest part of the state hasn’t seen the increase in moisture that the southeast part of the state has experienced, Blumenfeld said. So northwest Minnesota still gets bouts of heavy precipitation, but not as frequently as the southeast, he said.
Throughout Minnesota, “When it snows, it tends to snow more,” with increasing amounts of precipitation from snowstorms, Blumenfeld said.
The significant warming that has plagued other parts of the country, including the Pacific Northwest, has yet to reach the region including Minnesota, Blumenfeld said.
“We haven’t really gone outside the range of normal behavior,” he said, referring to heat wave temperature spikes. Although Minnesota has recorded some “real doozies,” they have not set heat wave records.
But, he added, “We do expect more heat waves.” Also, even if drought frequency doesn’t increase, drought intensity could increase, Blumenfeld said.
“This year could be an example of that,” he said. “We’re getting a pretty nasty drought.”
As of Aug. 5, more than 97% of Minnesota was experiencing moderate drought, more than 78% severe drought and 35% extreme drought.
All of North Dakota is experiencing at least moderate drought, with almost 98% in severe drought, 60% in extreme drought and almost 14% in exceptional drought, the most severe category.
The Red River Valley has experienced predominantly wet conditions since 1993, a period that included the 1997 flood that devastated Grand Forks and East Grand Forks and produced the record 2009 flood in Fargo-Moorhead.
That’s typical of the extreme precipitation events that have become more common due to climate change, Blumenfeld said.
“We definitely, in Minnesota and much of this region, have seen more extremes of precipitation, for sure,” he said.
As a result, average annual precipitation has generally increased throughout Minnesota, Blumenfeld said. Humidity also is increasing, a factor behind the record heat index in Moorhead in 2011 of 134 degrees.
Minnesota’s record high was 115 degrees, set in Beardsley in 1917. North Dakota’s record high was 121 degrees, recorded in Steele in 1936.
As the climate continues to change, the region can expect increased frequency of heat waves and fewer and less severe cold snaps, Wheeler said.
Changes in climate play out over decades, not in the span of a year or a few years, so people shouldn’t jump to conclude that an individual heat wave or cold snap is from climate change. “That’s really important for people to understand,” Wheeler said.
The upper Midwest has always been a land of weather extremes.
“We are so prone to hot and cold, wet and dry here,” he said. “We had so much variability to begin with.”
Still, as the latest report from the Intergovernmental Panel on Climate Change makes clear, climate change is real and playing out on a global scale, Wheeler said.
“It’s foolish to pretend it isn’t real,” he said. Too often, he added, people base their opinions on climate change on their political beliefs, whether conservative or liberal, and not on science.
Human activity — the burning of fossil fuels that produce greenhouse gases — is now undeniably altering the climate, Wheeler said.
“We can start blaming ourselves for future changes,” he said.