Table of Contents
- What is weather?
- What is climate?
- What characterizes Michigan’s climate?
- What are the global climate trends?
- Can individual weather events be attributed to climate change?
- What can be done to avert the worst impacts of Michigan climate change?
Michigan’s climate is changing. The state has experienced extreme weather events in the last few years, like the “polar vortex” events of 2014 and 2019 or the heavy rainfall and basement flooding in June 2021.
With such extreme weather becoming regular occurrences and worldwide temperature records routinely being broken, it’s worth taking a minute to think about what we mean when we say “weather” and “climate.”
What follows are answers to some common questions about weather and climate, including how climate change is affecting Michigan, the causes of global heating and what can be done to avert the worst impacts of the climate crisis.
What is weather?
Weather refers to the events in the atmosphere on the timescale of days, minutes and weeks.
“Climate is what you expect, weather is what you get,” according to the National Oceanic and Atmospheric Administration.
Almost all weather occurs in the troposphere, or the lowest level of the atmosphere, which extends from the earth’s surface to a height of roughly five miles. Factors like air pressure, humidity, temperature, wind speed and direction change the atmosphere, creating the weather for a specific time and location.
In Michigan, the Great Lakes can also influence weather. For example, Lake Michigan can mitigate against temperature extremes and provide moisture for lake-effect snow, according to Abby Hutson, assistant research scientist with the University of Michigan’s Cooperative Institute for Great Lakes Research.
What is climate?
Climate describes weather over longer periods than weather. Hutson said that latitude, proximity to water or being landlocked influence climate.
“Our climate is the average of all our weather,” she said. “Weather is daily and can change in a matter of hours…climate, as we define it, can take many years to change.”
NOAA illustrates the difference between rapidly changing weather and relatively slow climate change with the analogy that “weather tells you what to wear each day,” while “climate tells you what types of clothes to have in your closet.”
Climates can be regional or planetary and account for seasonal variability, average wind speeds and precipitation.
Scientists often look at long-term averages for these factors to describe the climate of a particular place.
The “U.S. climate normals” are 30-year averages of weather conditions. They’re often used to describe whether summer temperatures are likely to be hot and humid, whether winters will be cold and snowy and when a place might expect its warmest day of the year.
H2: How does the climate change?
Climate changes over longer periods of time than weather. Events like La Niña and El Niño often unfold over one or more years, causing changes to temperatures and precipitation across the U.S.
Yet, the climate is changing much more rapidly than in the past, with greenhouse gasses like methane and carbon dioxide trapping heat and warming the planet. Human activities like burning fossil fuels, deforestation and fossil fuel production drive this heating trend, which has been observed since the mid-20th century.
What characterizes Michigan’s climate?
Michigan has historically seen large seasonal changes in weather, according to the NOAA National Centers for Environmental Information. Michiganders will recognize this pattern of cold winters and warm, humid summers.
However, the Great Lakes mitigate against temperature extremes and increase humidity levels. This effect is greatest along the shores of the lakes, which are warmer than inland areas in winter and cooler in summer.
Hutson said that a decline in ice cover may also lead to more lake-effect snow
Michigan is already seeing the effects of climate change, with temperatures rising 3 F since the beginning of the 20th century.
Metro Detroit has seen a spike in the number of days above 85 F. Since 2010, at least three years have seen more than 60 days above 85 F: 2012, 2016 and 2018. In the sixty years prior, there were only three years with more than 60 days that were this hot.
lEarn more
Surviving a metro Detroit summer in the climate change era
A recording of our live webinar on summer in Southeast Michigan– extended heat waves, high-intensity rainstorms and worsening air quality.
Nighttime temperatures increase more rapidly than daytime temperatures. That’s especially concerning because high nighttime temperatures can deprive the body of a chance to cool down and increase the likelihood of heat illness. Between 2018 and 2023, the number of nights in Detroit with a temperature of 68 degrees or above increased by 18.
Rainfall has increased significantly over the last 30 years in Michigan and most of the eastern U.S., while many western states have seen less precipitation.
Hutson said it’s still being determined if this increase in precipitation will continue, but significant rainfall events are expected to occur more frequently as warmer air tends to hold more water vapor.
However, periods of drought could also become more common. The U.S. government’s Fifth National Climate Assessment predicts periods of drought and flooding to increase in the Great Lakes region, along with associated problems like harmful algal blooms and the expansion of invasive species.
A decline in ice cover could also increase lake-effect snow, according to Hutson. This phenomenon occurs when cold air passes over relatively warm water, transferring moisture into the atmosphere and generating snowfall.
Historically, lake-effect snow has been less common during the coldest months of winter, when the Great Lakes have more ice cover. However, with declining ice levels, this pattern may change.
Lake levels on the Great Lakes may become more variable as the region experiences more extreme droughts and precipitation events. From 1998 to 2013, the lakes had below-average water levels, followed by record highs in 2019 and 2020.
What are the global climate trends?
Globally, the climate crisis has produced dramatic heating in recent years. The hottest year on record was 2023 with land and ocean temperatures 2.12 F above the 20th-century average and record-low Antarctic ice cover.
“After seeing the 2023 climate analysis, I have to pause and say that the findings are astounding,” NOAA Chief Scientist Dr. Sarah Kapnick said in a web post. “Not only was 2023 the warmest year in NOAA’s 174-year climate record, it was the warmest by far.”
These trends continued in 2024. Global surface temperatures rose to 2.3 F from January to July above the 20th-century average.
The hottest day ever recorded was July 22, 2024, according to a NASA analysis of global daily temperature data
Can individual weather events be attributed to climate change?
Historically, researchers and the media held that individual weather events couldn’t be directly attributed to climate change. However, this view has been challenged by advances in attribution science. Using this science, groups like Climate Central and World Weather Attribution seek to show how climate change can influence the likelihood and severity of extreme weather events.
Climate Central’s Climate Shift Index uses peer-reviewed science to show the impact of climate change on weather conditions. For example, the index found that a record-breaking 73 F day in Detroit this February was three times more likely because of climate change.
Meanwhile, WWA provides in-depth reports on events like this year’s wildfires in Brazil, which found they were 40% more intense due to climate change.
What can be done to avert the worst impacts of Michigan climate change?
Scientists say humanity needs to take drastic measures to reduce greenhouse gas emissions to avoid the worst impacts of the climate crisis. The Intergovernmental Panel on Climate Change’s sixth assessment report says global CO2 emissions need to be reduced by 48% from 2019 levels by 2030, reaching “net zero” emissions by 2050. Net zero refers to the balance of carbon emitted into and removed from the atmosphere
Strategies for meeting these goals include increasing the use of wind and solar power for energy generation, creating more efficient public transportation, stopping deforestation to hold onto stored CO2, reducing methane emissions from fossil fuel infrastructure and agriculture, and closing coal power plants.