11/13/2019
Two Possible Climate Futures for the Great Lakes Region
Dr. David Karowe Department of Biological Sciences Western Michigan University
Temperature is rising at least 10 times faster than any time in the last 800,000 years
Temperature difference relative to 1950-1980
https://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=4609&button=recent
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How do we know that today’s climate change is not due to “natural factors”? Until ~1900, all climate change was due to natural factors
Have we been getting more energy from the sun?
For the past 40 years, while Earth has been warming fastest, energy from the sun has been decreasing
Over the past century, “natural factors” would have caused a slight cooling of Earth
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Best estimate: 100% of current warming is due to human activities
Fossil fuel burning (CO2) Deforestation
Is there any debate among scientists about whether humans are the primary cause of global warming? “Most of the global warming in recent decades can be attributed to human activities." Scientific organizations endorsing this statement: United States: National Academy of Sciences American Medical Association American Association for the Advancement of Science American Meteorological Society American Institute of Biological Sciences American Chemical Society American Geophysical Union American Institute of Physics
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National Aeronautics and Space Administration National Oceanic and Atmospheric Administration Geological Society of America American Academy of Paediatrics American College of Preventive Medicine American Public Health Association Environmental Protection Agency National Center for Atmospheric Research University Corporation for Atmospheric Research Ecological Society of America American Society of Agronomy American Society of Plant Biologists Association of Ecosystem Research Centers Botanical Society of America Crop Science Society of America
American Statistical Association Organization of Biological Field Stations American Physical Society Society for Industrial and Applied Mathematics Society of Systematic Biologists Soil Science Society of America Federation of American Scientists National Research Council National Association of Geoscience Teachers American Quaternary Association American Association of Wildlife Veterinarians American Society for Microbiology Society of American Foresters American Astronomical Society Natural Science Collections Alliance
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Europe: European Academy of Sciences and Arts European Science Foundation European Geosciences Union European Physical Society European Federation of Geologists Norwegian Academy of Science and Letters Royal Society of the United Kingdom Academie des Sciences (France) Deutsche Akademie der Naturforscher (Germany) Accademia dei Lincei (Italy) Royal Irish Academy Royal Swedish Academy of Sciences Royal Academy of Belgium for Sciences and the Arts Royal Meteorological Society British Antarctic Survey
Other countries (≥ 35): Chinese Academy of Sciences Science Council of Japan Russian Academy of Sciences Indian National Science Academy Royal Society of New Zealand Australian Academy of Sciences Australian Medical Association Polish Academy of Sciences Academia Brasiliera de Ciencias (Brazil) Royal Society of Canada African Academy of Sciences Caribbean Academy of Sciences Academy of Sciences of Malaysia Indonesian Academy of Sciences Academy of Science of South Africa
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Scientific organizations holding a dissenting opinion: 2007: American Association of Petroleum Geologists Since 2008: None For over a decade, no reputable scientific society on Earth has stated that humans are not the main cause of current climate change.
Nearly 100% of climate scientists (the experts) agree that humans are the primary cause of climate change today
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How has winter climate been changing in Michigan?
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Since 1970, winter temperatures have increased throughout most of Michigan
Since 1970, annual snowfall has increased slightly throughout most of Michigan
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How will future climate change affect the Great Lakes Region?
The magnitude of future climate change depends on our choices “Business as Usual” 4-5o C 950 ppm (7-9o F)
“Paris Agreement” 2 oC o 500 550 ppm (3.5 F)
400 (ppm)
2 2 300 CO 200 400,000 Today
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Paris Business Agreement as Usual
https://youtu.be/dBHL_7dEpTg
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By 2100 under Business as Usual, winter temperature would increase by ~12o F (~6.5o C)
BAU
But under the Paris Agreement, winter temperature would increase by only ~6o F (~3.5o C)
Paris AgreementBAU
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By 2100 under Business as Usual, winter precipitation would increase by ~10% Under the Paris Agreement, winter precipitation would increase by ~5%
Paris BAU Agreement
Under Business as Usual, the number of days per year below 32o F will decrease dramatically
By 2030: 18 fewer days
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Under Business as Usual, the number of days per year below 32o F will decrease dramatically
By 2030:2050: 1832 fewer days
Under Business as Usual, the number of days per year below 32o F will decrease dramatically
By 2030:2090:2050: 186532 fewer days
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Under Business as Usual by 2100, most winter precipitation will be rain rather than snow
Historical BAU
Winter Precipitation as Snow (%)
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Under the Paris Agreement, the number of days per year below 32o F will still decrease, but less dramatically
By 2030: 16 fewer days
Under the Paris Agreement, the number of days per year below 32o F will still decrease, but less dramatically
By 2030:2050: 1626 fewer days
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Under the Paris Agreement, the number of days per year below 32o F will still decrease, but less dramatically
By 2030:2050:2090: 162635 fewer days
Limiting warming to 1.5o C (Paris Agreement Extended) would preserve even more days below freezing
By 2090: 22 fewer days
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Under Business as Usual by 2080, Midland’s climate would be like Columbus, Ohio Under the Paris Agreement by 2080, Midland’s climate would be like Toledo, Ohio
The future depends on our choices With the Paris Agreement, 195 countries pledged to limit warming to 2o C and, if possible, to 1.5o C
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What can I do to minimize climate change?
1. Choose to use less fossil fuel energy - practice energy efficiency and conservation
>250 mpg
- however, by itself, only delays the outcome
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2. Choose to demand that our policymakers support smarter energy choices Target: ≥ 80% of energy from smarter sources by 2040
2. Choose to demand that our policymakers support smarter energy choices Target: ≥ 80% of energy from smarter sources by 2040
Solar Wind
Global potential: Global potential: 100 times 40 times total human energy use total human energy use
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Using only 2% of U.S. land, we could generate 100% of our energy by wind, water, and solar by 2050
- with concentrating solar power (CSP), excess heat stored during the day is used to produce electricity all night
3. Choose to talk about climate change causes, consequences, and solutions with friends with ones who think differently
with coworkers and especially with youth
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What percent of adults in Michigan are worried about global warming?
58%
What percent of adults in Michigan think most scientists believe global warming is happening?
46%
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Most expert economists believe the benefits of limiting warming to 2o greatly outweigh the costs
- benefits of limiting warming to 2o are typically estimated to be 5-20 times greater than the costs
4. Choose to join a climate truth organization
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5. Choose to make climate change a major voting issue
Bottom line: Michigan would benefit tremendously from limiting warming to 2o C. For a short time, it’s still an achievable target, and it’s worth fighting for.
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The future depends on our choices
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