Unit 6: Impacts of Increasing CO2

Let’s recap what we know.  Our Earth’s energy budget has been put out of balance by increasing the atmosphere’s load of CO2.  The increasing amount of CO2 is the result of human activity.  The result of the increase in CO2 has been more heat being reflected back down to Earth known as the “greenhouse effect”.   This greenhouse effect produces warmer temperatures world-wide, and this warming is expected to increase for decades or most likely even longer.  This was where the idea of “Global Warming” comes to an end and Climate Change starts.  Those people who don’t understand Climate Change will often say what’s the big deal, we’ll be 2 or 3 degrees warmer?  Those people don’t understand the effects this “small” amount of warming will do.  The increase in world-wide atmospheric and ocean temperatures are linked to a myriad of effects on the world around us, and many of those effects will pose a challenge to humans and wildlife across the globe.   

Here is a quick page on impacts to Wisconsin due to climate change by the EPA.  It just brushes over the potential effects, but it’s a good place to pick some effects and have students do more in-depth research on impacts to their state.  https://19january2017snapshot.epa.gov/sites/production/files/2016-09/documents/climate-change-wi.pdf

Heavy rainfall and flooding in Wisconsin due to Climate Change from Wisconsin Initiative on Climate Change Impacts (WICCI): https://www.wicci.wisc.edu/presentation-materials.php  You will need to scroll down to “Climate Change, Rainfall & Wisconsin Communities” pdf download.

The Fourth National Climate Assessment 2018, chapter on Midwest and climate change https://nca2018.globalchange.gov/chapter/21/

Flash video on Climate Change in WI by Wisconsin Initiative on Climate Change Impacts https://www.wicci.wisc.edu/climate-change.php

The EPA has a great website (now archived because of the Trump administration removal of all Climate Change information on most government website) you can find it here with impacts to Agriculture, Coastlines, Ecosystems, Energy, Forests, Human health, Society, Transportation, & Water Resources. https://19january2017snapshot.epa.gov/climate-impacts_.html

The U.S. Global Change Research Program (USGCRP) is a Federal program mandated by Congress to coordinate Federal research and investments in understanding the forces shaping the global environment, both human and natural, and their impacts on society.  The USGCRP produced the “National Climate Assessment” in 2014. It’s an excellent resource on the projected impact of Climate Change on the United States. Their website. https://nca2014.globalchange.gov/highlights/overview/overview

The quick takeaway from this large study:

Key Messages

1. Global climate is changing and this change is apparent across a wide range of observations. The global warming of the past 50 years is primarily due to human activities.

2. Global climate is projected to continue to change over this century and beyond. The magnitude of climate change beyond the next few decades depend primarily on the amount of heat trapping gases emitted globally, and how sensitive the Earth’s climate is to those emissions.

3. U.S. average temperature has increased by 1.3°F to 1.9°F since record keeping began in 1895; most of this increase has occurred since about 1970. The most recent decade was the nation’s warmest on record. Temperatures in the United States are expected to continue to rise. Because human-induced warming is superimposed on a naturally varying climate, the temperature rise as not been, and will not be, uniform or smooth across the country or over time.

4. The length of the frost-free season (and the corresponding growing season) has been increasing nationally since the 1980s, with the largest increases occurring in the western United States, affecting ecosystems and agriculture. Across the United States, the growing season is projected to continue to lengthen.

5. Average U.S. precipitation has increased since 1900, but some areas have had increases greater than the national average, and some areas have had decreases. More winter and spring precipitation is projected for the northern United States, and less for the Southwest, over this century.

6. Heavy downpours are increasing nationally, especially over the last three to five decades. Largest increases are in the Midwest and Northeast. Increases in the frequency and intensity of extreme precipitation events are projected for all U.S. regions.

7. There have been changes in some types of extreme weather events over the last several decades. Heat waves have become more frequent and intense, especially in the West. Cold waves have become less frequent and intense across the nation. There have been regional trends in floods and droughts. Droughts in the Southwest and heat waves everywhere are projected to become more intense, and cold waves less intense everywhere.

8. The intensity, frequency, and duration of North Atlantic hurricanes, as well as the frequency of the strongest (Category 4 and 5) hurricanes, have all increased since the early 1980s. The relative contributions of human and natural causes to these increases are still uncertain. Hurricane-associated storm intensity and rainfall rates are projected to increase as the climate continues to warm.

9. Winter storms have increased in frequency and intensity since the 1950s, and their tracks have shifted northward over the United States. Other trends in severe storms, including the intensity and frequency of tornadoes, hail, and damaging thunderstorm winds, are uncertain and are being studied intensively.

10. Global sea level has risen by about 8 inches since reliable record keeping began in 1880. It is projected to rise another 1 to 4 feet by 2100.

11. Rising temperatures are reducing ice volume and surface extent on land, lakes, and sea. This loss of ice is expected to continue. The Arctic Ocean is expected to become essentially ice free in summer before mid-century.

12. The oceans are currently absorbing about a quarter of the carbon dioxide emitted to the atmosphere annually and are becoming more acidic as a result, leading to concerns about intensifying impacts on marine ecosystems.



This Time Machine interactive maps by NASA shows changes in CO2 concentrations, Temperature, Sea level, and ice cover.  https://climate.nasa.gov/interactives/climate-time-machine

This Impact unit is a chance for students to learn how Wisconsin is and will be impacted by climate change.  If you ask most students, they might not have noticed much, if any impacts, so this is the time to make climate change tangible for your students.  Some important ways of life in Wisconsin will change due to climate change.  From the above EPA “impacts on Wisconsin” they hit upon the effects to agriculture, fish, water, habitat, human health, and winter recreation.  All of these topics will have a direct negative impact on Wisconsin’s economy!  One topic this webpage omits is Sugar Maple Trees.  Increasing temperatures may push Sugar Maples out (North) of most of Wisconsin.  I use the word “may”, as some studies surrounding Sugar Maple trees are not sure if this will happen at all, or it may take hundreds of years.  I believe it’s good for students to know that not everything predicted is guaranteed to happen.  But the message of “why risk the possibility of it happening” is important when human choices impact how severe climate change will become. 

A topic that is controversial in the scientific world is the possibility of long term droughts brought on by climate change. Many studies in the 90’s and 2000’s have said weather patterns have a better chance of becoming stuck, leading some areas to experience long term drought because the jet-stream get stuck into a long-term pattern leading to a long-term effect on weather, all this due to warming atmospheric temperatures.  New studies in 2019 and 2020 have said that they found no evidence of weather patterns sticking due to climate change. The article referenced below hits on both sides of the controversy and basically it says more research needs to be completed.  Other studies are simply concerned that higher temperatures due to climate change with higher rates of evaporation will further enhance drought in already arid and semi-arid regions.  https://www.sciencemag.org/news/2020/03/why-does-weather-stall-new-theories-explain-enigmatic-blocks-jet-stream#

Here are links to Climate Change and Sugar Maples:

CC effects on Sugar Maples NPR  https://www.npr.org/sections/thesalt/2018/02/12/584528440/climate-change-could-mean-less-maple-syrup-for-your-pancakes 

More scientific look at Climate Change & sugar maples https://necsc.umass.edu/sites/default/files/NECSC%20one-pager%20Maple%20Project%20170428.pdf


UMASS Climate Change & sugar maples https://necsc.umass.edu/projects/climate-effects-culture-and-ecology-sugar-maple


Science Daily article on Climate Change & sugar maples https://www.sciencedaily.com/releases/2019/09/190920145348.htm


U.S.G.S. Climate Change & sugar maples https://www.usgs.gov/centers/casc-sc/science/climate-effects-culture-and-ecology-sugar-maple?qt-science_center_objects=0#qt-science_center_objects


Forest Service on sugar maples https://www.fs.fed.us/nrs/pubs/jrnl/2018/nrs_2018_oswald_001.pdf


You can take one each of the above 12 key points and hand them out to groups of 2-4 students.  Have the students find evidence that support their issues and then present their findings to the class.  To make this lesson plan more pertinent to students in Wisconsin, I looked for projected impacts to people living in Wisconsin.  I’ve found four areas in Wisconsin that will be impacted by climate change.  They are:  Farming, Diseases, Fishing, and Maple Syrup.   A roundup of climate change impacts on the Midwest can be found on the EPA website (as of this time a snapshot of the website is all that is available since the Trump administration ordered all climate change information removed from their website): https://19january2017snapshot.epa.gov/climate-impacts/climate-impacts-midwest_.html


Farming will be impacted many ways.  Increased temperatures will (and has) created a longer growing season.  Warmer temperatures can have a positive effect on crops (if the weather stays in their favor which includes adequate moisture with more growing degree days).  https://www.scientificamerican.com/article/ask-the-experts-does-rising-co2-benefit-plants1/  


But to temper the positive effects to crops the warmer winters, warmer winters will help to encourage pest populations that could literally eat into farmers crops.  From Foodtank.com 



Also, while the crops might flourish under warmer conditions so will weeds, so weed control will become a greater problem. From Researchgate.net  https://www.researchgate.net/publication/322754402_Impact_of_climate_change_on_Weeds_and_Weed_management-A_review 


Wisconsin farmers have already had to contend with flooding rains, washing out new plantings and flooding fields.  This trend of flooded fields is expected to continue and most likely get worse. 



By the EPA: “In the Great Lakes and smaller lakes in the Midwest region, increased temperatures are likely to affect fish species. Warming waters are expected to reduce the abundance of many cold-water species, including brook trout, lake trout, and whitefish. Cold-water species, such as Muskie, Smallmouth Bass, and Bluegill are expected to increase. The habitat of many fish species may also be degraded by harmful algal blooms, coastal erosion and flooding, and pollution runoff.  Increasing air temperatures will also lead to increasing water temperatures.  Warm water fish will do better in warmer water than cold water fish will”.

Fishing and Climate Change from the U.S.G.S: https://owi.usgs.gov/vizlab/climate-change-walleye-bass/

Fishing and Climate Change by Wisconsin Initiative on Climate Change: https://www.wicci.wisc.edu/coldwater-fish-and-fisheries-working-group.php

Ice Fishing and Climate Change in WI by ClimateWisconsin.org : https://climatewisconsin.org/story/ice-fishing.html


Forest by the EPA: https://archive.epa.gov/epa/climate-impacts/climate-impacts-forests.html


ClimateCentral.org does a good job at pointing out problems caused by climate change by 2050 for 244 cities in the U.S.   I use the word good because the impacts on our lakes, rivers, fish, & winter sports and how they impact our economy seem to be omitted.  https://www.climatecentral.org/gallery/maps/top-climate-hazards-in-2050

Problems of local flooding WBAY-TV Green Bay, WI: https://www.wbay.com/content/news/Protecting-Properties-Along-Green-Bay-567206231.html

Heavy rainfall the new normal. Post Crescent Appleton, WI https://www.postcrescent.com/story/news/2019/10/02/wisconsins-record-rain-totals-result-unusual-weather-patterns/3831707002/

Climate Central and how Climate Chage intensifies heavy rain events  https://www.climatecentral.org/news/report-pouring-it-on-climate-change-intensifies-heavy-rain-events

How Heavy rainfall has increased and will continue to get worse by Climate.gov https://www.climate.gov/news-features/featured-images/prepare-more-downpours-heavy-rain-has-increased-across-most-united-0

Why extreme rains are getting stronger by Nature.com: https://www.nature.com/articles/d41586-018-07447-1

Top 10 weather events in WI by year, these resources could be a useful assignment to pick out weather trends that may be linked to climate change.  Probably the easiest topics would be record rainfall or record snowfall as well as record warm months, and compare them to the 100+ years of weather records.

2019 https://www.weather.gov/media/mkx/WCM/2019wisconsinevents.pdf

2018 https://www.weather.gov/media/mkx/WCM/2018wisconsinevents.pdf

2017 https://www.weather.gov/media/mkx/WCM/2017wisconsinevents.pdf

 Top 10 2010-2019 https://www.weather.gov/media/mkx/WCM/2010swisconsinevents.pdf

Class plan by Sandford Earth: https://earth.stanford.edu/climate-change-ed/curriculum/high/consequences-climate-change-adaptation