Climate experts predict wetter, more turbulent weather
A pair of Michigan State University climate experts won’t flat-out blame humans for the climate changes they see happening.
But Dr. Jeffrey A. Andersen and Dr. David P. Lusch say the changes are real.
“I really don’t care where you are on issue of whether there are anthropological (human) causes of it,” Lusch said at the Saginaw Bay Watershed Conference Friday at Saginaw Valley State University.
“I want to tell you that the climate is changing and you all have to get ready for it.”
Both members of MSU’s Geography Department said Saginaw Bay watershed residents, like those throughout Michigan and Midwest, will likely see long-term weather both warmer and wetter — plus more extreme events such as recent tornadoes and perhaps even the current late-spring-like spell of weather.
Already, spring warm-up comes 1 to 1 1/2 weeks earlier than it did 30 years ago, Andersen said. And, “If forecasts for next week are correct, we could be looking at the warmest March on record. That would have many effects on agriculture, many of them bad.”
Average temperatures in this region have increased 1 to 2 degrees F since 1980, Lusch said in his presentation, and global climate models point to increases of 2 to 7 degrees F by the turn of the century in the Midwest overall, a degree higher yet in Michigan. Most dramatically higher, he said, are average nighttime low temps.
Conditions have gotten steadily wetter since the 1920s, Andersen said, with annual rainfall now four inches or more higher than then.
Current trends are for that to continue, but both speakers said much of the increase will likely come in big gulps, extreme precipitation events that can cause floods and overpower infrastructure.
And most of the increased precipitation will come in cool seasons. Ironically, summers will likely be drier.
Heavy rain events in all seasons “have been increasing since the 1950s, the 1960s,” said Andersen, “and they’re still going.” Almost one-third of annual rainfall comes in 10 heavy precipitation events, he said.
Of concern to many at the conference — those storms can bring big shots of runoff pollution to the Bay, too.
Beyond the extreme events, there are more “wet” days per year than in the past, Andersen said, and more of them back-to-back.
Snowfall is less through much of the region, with notable exceptions the Keweenaw Peninsula in the Upper Peninsula, and northwest Lower Michigan, where lake effect snows are heavier — likely because the Great Lakes don’t freeze as widely or long, increasing evaporative water loss and weather turbulence. Otherwise, there are fewer days of snowcover statewide.
Soil moisture has also increased, as measured in the top five feet of soil and across the calendar. But it’s in increasingly short supply during the second half of July and August
Earlier forecasts of dramatic declines in Great Lakes levels have been trimmed recently, as predicting models have been corrected. Lusch said lake level shifts caused by climate change won’t be much more dramatic than natural shifts over time.
Lusch expects spring freshets — winter ending runoffs — to come earlier and with less flow.
Low stream levels of summer may be lower, and last longer — while peak flows may increase, due to heavy rain events.
Because more of a year’s precipitation may come in extreme events with rapid runoff, groundwater recharge and groundwater levels may decrease.
“It will be a warmer, wetter world” in decades to come, said Andersen, with more erratic weather events.
Ice fishermen will have shorter seasons, Lusch predicted. Farmers may be forced to rely on irrigation in summer.
And whatever your opinion of the cause of climate change, Andersen and Lusch told conference attendees it’s real. They urged the government officials, educators, conservation group representatives and students in the conference audience to make plans to deal with it.