Effects of climate change in Minnesota

Flooded farm near Cologne Minnesota

More and more, Minnesotans are starting to notice the effects of climate change here at home. Across the state, communities and individuals are experiencing higher temperatures, more extreme storms with intense flooding, and changes in our unique and cherished ecosystems.

Climate change, caused primarily by the excess release of greenhouse gases, is having a real and significant impact on communities all over the world. Greenhouse gases that have the most impact on climate change include carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4), sulfur hexafluoride (SF6), hydrofluorocarbons (HFCs), and perfluorocarbons (PFCs).

Much of the excess greenhouse gas emissions come from human activities — burning fossil fuels for transportation or electricity generation (CO2); agricultural and animal husbandry practices (methane), or air conditioning units (HFCs).

Only some like it hot

Rows of small green corn plants in a field on a bright sunny day.

In the Twin Cities, annual average temperatures increased by 3.2° F from 1951 to 2012, which was faster than both national and global rates of increase. This doesn’t seem like much, but in the cities, that small increase can add up. Some parts of the cities can spike up to 9° higher than other areas. On an 88° day, that means that temperatures in some places can rise to over 100°. This phenomenon is referred to as an urban heat island, and conditions can be dangerous for those caught unaware or unprepared. Individuals that live in dense, urban areas of environmental justice concern, including low income and/or communities of color, can be especially impacted.

Statewide, temperatures have increased 1° to 3° F. Average low temperatures have risen more quickly than the average highs throughout the state, especially nighttime lows. Temperatures in the northern part of the state rose even more quickly than those in the central and southern portions.

Based on historical trends, models project that the average temperature in the Twin Cities metro area will rise between 3° and 5° F through mid-century, with more high temperature days (days above 90° F). Temperatures in Greater Minnesota are also projected to rise. Some folks think that these warmer temperatures will support agricultural efforts and increase productivity, but the real threat to crops are days that reach temperatures above 95° F. Corn, in particular, can be irreparably damaged when temperatures are at or above 95° F for one or more days.

Rain, snow, and sleet

Main street of a small town completely flooded with water.

Have you thought recently about how rainfall in Minnesota seems different than it used to? Well, you’re probably right. Between 1951 and 2012, total precipitation amounts increased by over 20% (5.5 inches) in the Twin Cities. Increasing rainfall in the spring and autumn months accounted for most of that increase. In Greater Minnesota, more frequent heavy rains have been causing low areas to flood, resulting in crop, home, and business damages. The northwest corner of the state, on average, gets 15 inches less precipitation than the southeast (an annual average of 22 inches compared to 36 inches, respectively).

Looking into the future, most climate models show at least a slight increase in projected annual precipitation across the state. Models also show stable or decreasing summer precipitation. That means that our hot summers will likely be drier, and our warmer winters will be snowier (or wetter).

Many models have indicated that the patterns and distribution of rain and snowfall will change, too. Instead of getting smaller rainfalls spread out over time, rainfall will likely happen less frequently but with more intensity. These sorts of rainfalls, usually accompanied by heavy storms, can cause flash flooding. These sudden and intense floods can cause significant property damage, and can even lead to deadly situations for those caught unprepared. Warming winters may also lead to more freezing rain or sleet instead of snow in some areas, and wetter, heavier snow in others.

Changes to our natural environment

A thicket of slender tree trunks with early spring leaves in a wetland.

It may be hard for us humans to tell when the temperature slowly rises by 3° F, but native wildlife and plants are much more sensitive to climate change impacts, and they are already suffering.

As Minnesota sees higher temperatures, warming surface waters in the state are leading to a significant loss of fish habitat for many prominent species, including trout and walleye. Higher temperatures, in combination with increased stormwater runoff and erosion caused by heavier rain, means that many bodies of water will be home to algae blooms. Such blooms can negatively impact species that may benefit from warmer water, like bass, by removing extra oxygen in the water, essentially suffocating the fish that live there.

Northern Minnesota is experiencing warming trends more quickly than the rest of the state, particularly during the winter months. Anyone that has spent time up north over the past few decades can attest to the changing forests. As our climate warms, northern tree species liked paper birch, quaking aspen, balsam fir, and black spruce may start to die out, with populations moving further north. Warmer-climate tree species, like maples, oaks, and hickories could take their place. These changes in tree cover are accompanied by changes in the understory and soil, meaning that habitat for wildlife is changing along with the trees.

Migratory animals, which many Minnesotans are excited to see every year, are also being impacted by climate change. With less predictable temperatures and rainfalls, birds are arriving earlier, and their breeding seasons are moving up in the year, too. Even animals that stay in Minnesota year-round are experiencing changes in the timing of food availability. This is a problem because not all species of animals and plants have reacted the same to changes in temperature or rainfall, meaning that a bird that arrives earlier or deer that breed sooner may end up not having enough food to sustain themselves. The timing of native and honey bees emerging and plants blooming is presenting a problem, as well, which could have far-reaching and lasting consequences for native and cultivated species.

So what?

The cumulative impacts of climate change are having real impacts on Minnesotans and our economy by forcing early and costly repairs to infrastructure, increasing home and crop insurance rates, contributing to upheaval in our native ecosystems, and causing more trips to the hospital for heat-related illness.

Some communities in areas of concern for environmental justice are feeling the impacts of climate change more acutely than others, particularly those nearby electricity generating facilities, where they are exposed to higher greenhouse gas emissions.

The MPCA has developed an online data tool to look at the effects of electricity generation on various communities in Minnesota, and to find out if the most vulnerable communities are seeing benefits from the significant reductions in emissions from electricity generation.

For more information