climate change in the midwest
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Climate Change in Wisconsin and the MidwestDaniel J. VimontUniversity of Wisconsin – Madison Atmospheric and Oceanic SciencesNelson Institute Center for Climatic ResearchWisconsin Initiative on Climate Change Impacts (WICCI)@DanVimont
The Wisconsin Initiative on Climate Change ImpactsWICCI
WICCI: Enabling climate adaptation in Wisconsin and the Midwestwww.wicci.wisc.edu
The Wisconsin Initiative on Climate Change Impacts
Climate Information AdaptationWICCI
WICCI’s mission is to generate and share information that can limit vulnerability to climate change in Wisconsin and the Upper Midwest.
OutlineDownscaled Climate DataTemperature Changes and ImpactsPrecipitation Changes and ImpactsWhat do people really care about?
Problem: Climate models have coarse spatial resolution.Downscaling: Focus global projections to a scale relevant to climate impacts.
Global à Local Climate Change
Problems with simple interpolation:
Global to Local Climate Change
Moving from Global to RegionalDownscaling Method:Downscale Probability Distribution, instead of actual variable.
Advantages:• PDF is large-scale, so method is “truer” to existing data• Extreme events are well characterized• PDFs are more flexible – allows a variety of applicationsWork by David Lorenz - WICCI Climate Working Group /
UMGL LCC
Future Climate Projections:Global Climate Model data from CMIP3 (IPCC AR4)
• Numerous (13) models used, to obtain a range of possible future projections
Downscaling methodology resolves the range of probable climate change
• Range is essential for impact assessment• Extremes are well represented
Probability distributions are FLEXIBLE! • Data can be used in a number of different ways, by groups with very different needs
Outline
l Downscaled Climate Datal Temperature Changes and Impactsl Precipitation Changes and Impactsl What do people really care about?
Annual Temperature Change
Annual Temperature Change
Wisconsin will warm by 3°– 9°F by mid-
21st century
Winter Temperature Change
Warming is most pronounced for winter nights
(Wisconsin winters warm by 5°–
12°F by mid-21stcentury)
Cold Days
Days < 32°F Days < 0°F
Fewer Cold / Extremely Cold Days
Winter Impacts
Freeze / Thaw Cycles
Fewer Freeze / Thaw Cycles per year
1950-2000: ~95 freeze / thaw cycles per year.
2046-2065: 60-85 freeze / thaw cycles per year: a decrease of about 15-30%
Summer Temperature Change
Warming is least pronounced for summer days
(Wisconsin warms by 2°– 8°F by mid-21st century)
Extreme Heat
Mid-Century: More “very hot” days
Days > 90°F Days > 100°F
Extreme Heat
More hot days AND hot nights
Extreme Heat: Daytime Highs
Realistic temporal structure allows investigation of event duration.
Heat waves: 3 to 5 times more frequent
Days > 90°F
Extreme Heat: Daytime Highs
Realistic temporal structure allows investigation of event duration.
Nights > 70°F
Night heat waves: 5 times more frequent
THI: Extreme Caution, and Danger
By mid-century, “Danger” heat index becomes a regular occurence
Vapor Pressure Deficit
Warmer temperatures, similar relative humidity è Increased VPD by about 10%-25%
Regional Perspectives
Extreme Heat Extreme Cold
OutlineDownscaled Climate DataTemperature Changes and ImpactsPrecipitation Changes and ImpactsWhat do people really care about?
Annual Precipitation Change
Wisconsin will get 0%–15% wetter by mid-21st century
Winter Precipitation Change
Robust increase in Precipitation during Winter and Spring
More winter/spring precipitation= Increased groundwater recharge
Runoff Recharge ET Precip-40
-20
0
20
40
60
80
100
120
140
Mea
n an
nual
cha
nge
(mm
)
CRCM ccsmCRCM cgcm3HRM3 gfdlHRM3 hadcm3
Mean An
nual Change (m
m)
Runoff Recharge ET Precipitation
Black Earth Creek Watershed1971-‐1999 vs 2041-‐2069
Evan Murdock
45%
Winter +20-‐25%
Winter +6-‐7⁰F
Increased recharge= Groundwater flooding
Spring Green - 2008
Especially in communitiesthat do not disinfect
Rising water table can result in groundwater contamination
Gotkowitz & Liebl, 2013
Summer Precipitation Change
No consensus during Summer!
Summer Precipitation Change
Large Precipitation Events
Southern Wisconsin could see a 30% increase in the number of
large rainfall events
OutlineDownscaled Climate DataTemperature Changes and ImpactsPrecipitation Changes and ImpactsWhat do people really care about?
The arrow of time
1950 2015 20502025
Long planning horizonsClimate change occurs over decades, are stakeholder planning and
management strategies in the same time frame?
42.8⁰F
48.7⁰F
Stakeholder planning horizons
What have you heard from your stakeholders about changes in, or events caused by, Wisconsin's weather?
Most stakeholders (n = 82)talk about the weather
It's the weather!(21%)
Agriculture & Weather(34%)
Precipitation & Weather
(21%)
Other topics(24%)
Climate change(29%)
Agriculture & CC(36%)
Precipitation & CC(3%)
Other topics(31%)
About half as many (n = 42)talk about climate change
Most people are thinking short term weather
0 5 10 15 20%
Increased numbers and intensity of heavy rain events/floods
Rising groundwater levels
Which climate impacts affect your stakeholders?Percent of all answers (n=912)
Drought periods in late summer
Increased duration and intensity of heat waves
Long periods of extreme cold
More precipitation in fall, winter and spring
Warm, wet winters w/frequent ice storms
They are most concerned about extreme weather
Additional Resources
WICCI Assessment Report: http://www.wicci.wisc.edu/publications.phpNational Climate Assessment: http://nca2014.globalchange.gov/National Academies Climate Change: http://nas-‐sites.org/americasclimatechoices/Risky Business: http://riskybusiness.org/
