Widespread flooding due to torrential rainfall in recent weeks has been devastating for Minnesotans across the state, from Nobles County farmers losing crops as their fields went underwater to the partial failure of the century-old Rapidan Dam on the Blue Earth River.
While climate scientists say the timing of the rainfall is fairly normal after drier conditions in recent years, what isn’t normal is its intensity. As the globe warms and Minnesota gets wetter in turn, environmental advocates say the state needs to take further action to adapt to the changing climate and worsening weather caused by global warming.
After a few years of drought conditions, Minnesota has come in this year with one of the wettest years on record so far, said Kenny Blumenfeld, senior climatologist at the Minnesota State Climate Office. This recent bout of weather began in March when we entered an “active weather pattern,” which is characterized by the movement of weather systems and can lead to significant changes in weather in short periods.
That then led us to an eight-day period that started on June 15 with significant downpours of rain in northern Minnesota, and culminated with several thunderstorms producing even more rain between June 19 and June 22. The entire state was pounded by heavy rainfall, with more than 50% receiving at least three inches of rain or more, and several parts of the state getting four to 11 inches.
Blumenfeld said it’s normal for the state to receive a lot of precipitation after a dry period the past few years, following a pattern that has been observed for decades. But, he said, not only are wetter periods getting wetter and producing more rainfall, drier periods are wetter than drier periods in the past.
“Part of what we’re experiencing is a totally natural occurrence because we’re coming out of dry conditions and our hydroclimate tends to bounce back within one to three years and produce a lot of precipitation,” he said. “But another part of what we’re seeing is that as the global climate has warmed, there’s more water in the atmosphere, meaning that there’s more fuel for passing weather systems which means that they can produce more precipitation and so now some parts of Minnesota are just about as wet through July 1 as they have ever been.”
Flooding can have positive impacts on the environment that include the depositing of nutrient-rich sediment, recharging aquifers and fertilizing vegetation. Where it becomes problematic is on the human side, said Paul Jackson, professor of chemistry and environmental studies at St. Olaf College.
“Oftentimes we have constructed buildings, settlements, cities in floodplains that normally would have flooded and so we end up seeing a lot of pressure on built infrastructure,” he said. “(Floods) can also carry waste products from agricultural fields that manure has been spread on, or where just the sheer volume of water being asked to be processed through say a wastewater treatment plant just gets inundated and can’t handle it anymore, leading to emergency release of untreated wastewater into the system.”
Jackson said as extreme weather conditions due to climate change are anticipated to become more common, more stress will be put on infrastructure across the state like culverts under roads, bridges, dams and even roadways.
Related | Farmers adding up their losses in southwestern Minnesota after flooding devastates crops
“Our built infrastructure was designed for a different climate regime,” he said. “All of that will be put under increasing amounts of pressure and maintenance costs will probably increase as events continue to increase in magnitude … townships and cities are really starting to ask questions of how they can create resilient infrastructure in the face of these changes.”
The state has started implementing efforts to adapt and build resilience, and among those efforts is $100 million given to the Minnesota Pollution Control Agency by the Legislature last year to fund a climate resilience and water infrastructure grant program. The money is meant to be used to improve the resiliency of infrastructure like stormwater and wastewater systems amid more common extreme weather like the recent floods.
Though adaptation efforts are important, mitigation through eliminating factors that contribute to worsening climate change should also be a main goal, said Peter Wagenius, legislative director for the North Star chapter of environmental advocacy organization Sierra Club. Citing the 100% clean energy bill passed by the Legislature last year, which requires utilities to provide 100% carbon-free energy by 2040, Wagenius said the state needs to act on more efforts that prevent the use of fossil fuels emitting greenhouse gasses into the atmosphere and making things worse.
“There’s no amount of resilience we can build into an ever heating planet,” Wagenius said. “We have to simultaneously stop the heating while we adapt and make ourselves more resilient to the warming that’s already baked into the system.”
Mohamed Ibrahim
Mohamed Ibrahim is MinnPost’s environment and public safety reporter. He can be reached at mibrahim@minnpost.com.
