REGIONAL— Minnesota needs to step up its investment in renewable energy to head off the worst effects of climate change, while it works at the same time to adapt to the climate changes that are …
REGIONAL— Minnesota needs to step up its investment in renewable energy to head off the worst effects of climate change, while it works at the same time to adapt to the climate changes that are already inevitable due to the build-up of greenhouse gases.
That’s the upshot of a new report by the Interagency Climate Adaptation Team, a group of Minnesota state agency leaders focused on adapting to climate change. The report, Adapting to Climate Change in Minnesota, says many of the effects of climate change, such as much warmer winters and heavier rainfall events, are already apparent in Minnesota and will only increase in scale and intensity over time.
Based on recent climate data, the report highlights the changes that are already occurring in Minnesota’s climate. The report cites the rapid decline in the severity and frequency of cold weather outbreaks and increase in extreme rainfall events as the two most definite signatures of climate change in Minnesota.
“Many people are surprised to learn that much of the observed temperature increase in Minnesota has not resulted from more warm weather, but instead from major reductions in cool and cold weather,” states the report. “The majority of Minnesota’s warming has taken place where and when it’s usually the coldest— namely during winter, at night, and especially in the northern parts of the state.”
One of the most notable changes is the increasing rarity of minus-40 degree temperatures in northern Minnesota. Minus-40 degree temperatures used to occur in about 90 percent of northern Minnesota winters. Yet over the 22 most recent winters, only 60 percent have seen a temperature reading of minus-40, and those readings are typically limited to the coldest locations in the region.
While the decline of minus-40 degree readings may qualify as good news to most Minnesotans, the impact of that change on northern Minnesota could be dramatic, according to Lee Frelich, a forest ecologist with the University of Minnesota. “If climate change did nothing other than eliminate a few hours of minus 40-degrees each winter, it would still cause huge changes,” said Frelich, who notes that the extreme cold once typical in a northern Minnesota winter is a critical threshold that keeps a number of potentially devastating insect pests under control.
Indeed, according to a recent paper produced by Frelich, titled Seven Ways That a Warming Climate Can Kill the Boreal Forest, uncontrolled insect invasions are the most likely way that boreal forests could be wiped out as a result of climate change.
One of the most worrisome of those pests, according to Frelich, is the mountain pine beetle, which has devastated pine forests in the western U.S. While the insect pest has not yet moved east of the Great Plains, Frelich notes that it has now spread far enough north that it has reached portions of Saskatchewan where the ranges of lodgepole pine and jack pine merge. Jack pine are closely related to lodgepole pine and the beetle will readily infect jack pine as well as red pine if given the opportunity. That opportunity could well come soon, said Frelich. “All we need is a run of mild winters across Saskatchewan and Manitoba and we could have it in Minnesota,” he said. That could quickly wipe out pine forests in northern Minnesota, causing a conversion to oak, red maple, and brush, a transition that is already happening, albeit at a slower pace than would be expected in the wake of an insect invasion.
Minus-40 degree temperatures also used to limit the ability of species like red maple and oak to survive in northeastern Minnesota, but winters are no longer the impediment they used to be to those species.
And it isn’t just forests that could be affected according to the new state report. “The reality is that we have already begun to see detrimental impacts on our natural resources and availability of popular winter recreational activities, such as ice fishing and skiing,” the report states. The snowmobiling season has also grown shorter and more erratic, due to more frequent mid-winter melting of snow.
The warming has been most dramatic in northern Minnesota, where winter is now nearly five degrees warmer than the long-term average in the region and many climate scientists expect winters to warm as much as ten more degrees within 50 years.
Northern Minnesota is also experiencing slightly warmer summers, while summer in the southern two-thirds of the state has been trending slightly cooler in recent years.
“The geographic and seasonal patterns of observed warming are consistent with changes expected from increased atmospheric greenhouse gases, because those gases trap heat escaping from the earth, and the majority of heat escapes when there is little or no incoming sunlight — during winter and at night,” states the report.
While warming temperature may have major impacts to the state’s ecosystems, wildlife, forests, and tourism, government officials are perhaps most concerned about the high cost of damage to infrastructure due to the increasing number of extreme storm events.
“For several decades, Minnesota has seen increased precipitation throughout the year, particularly from larger and more frequent rainstorms,” notes the report. Indeed, over the past 40 years, the likelihood of the most extreme rainfall events has doubled. “The single heaviest rainfall amount recorded per 10-year interval has roughly doubled (from just over five inches to just over 10 inches) during that same period,” notes the report. The damage that such storms can cause has been increasingly evident in recent years.
Minnesota has also seen a dramatic increase in large-coverage flash floods events in recent years, according to the report. “Since the year 2000, the state has had seven catastrophic “mega-rain events” — when at least six inches of rain falls on an area greater than 1,000 square miles. The 30 years from 1970 through 1999 saw only four such storms, and 2016 became the first year on record with more than one. Incidentally, the mega-rains since 2000 have included the largest, earliest, and latest on record, suggesting that we are seeing not just an intensification, but also a lengthening of our heavy and extreme rainfall season.”
The report highlights measures that state government is taking to adapt, such as increasing weatherization of homes and buildings, “greening” infrastructure with trees and landscaping to improve runoff control, assessing roads and bridges to identify those most vulnerable to damage, and restoring wetlands to buffer flooding.
The aim of these measures is to build resiliency into the state’s critical systems. “Climate change is bringing serious effects that we’ll have to live with,” said David Thornton, assistant commissioner of the Minnesota Pollution Control Agency, a founding agency of the team. “Building resilience is about making the systems that support our health and economy more prepared for these challenges.”
While the team focuses on adapting to climate change, the report acknowledges that without serious attempts to also slow the pace of change, humans and natural systems will find it increasingly difficult, if not impossible, to adapt.
In many cases, adaptation measures also can help reduce the rate of change. For example, increasing tree cover provides resilience to higher heat by providing cooling shade, while at the same reducing energy use for air conditioning. And improving water conservation builds resilience to drought by reducing use of groundwater and surface water, while also reducing energy used to purify and distribute water.
A warming and more extreme climate will also bring a variety of health concerns, including poorer air quality during hot and humid weather, as well as poorer overall water quality due to increased growth of algae and bacteria in the state’s public waters, and the spread of insect-borne disease.
Minnesota Department of Health Commissioner Ed Ehlinger noted that the health effects of climate change fall disproportionately on the state’s most vulnerable people. “Minnesota’s changing climate will affect the health of all of us, but we know that those with the fewest resources and those most vulnerable - physically, geographically, economically, socially – will be hit the hardest. We need to step up our efforts to build resiliency and protect the most vulnerable in our communities all across the state,” he said.
Given the change that has already occurred and the risks that lie ahead, state officials say the need for more dramatic action is apparent— and that the effort to head off the worst effects of climate change can bring real benefits to Minnesota.
“Addressing climate change will be good for our health, our environment, and our economy,” said Lt. Governor Tina Smith. “Next session, I urge the Legislature to adopt the bipartisan ‘50 by 30’ renewable energy standard proposed earlier this year.” The standard would require that 50 percent of Minnesota’s energy production comes from renewable, carbon-free sources, by 2030. Smith notes that the measure has multiple benefits. “It will create new jobs and reduce greenhouse emissions in our state,” she said.