Wisconsin’s Changing Climate: Recent Trends and Future Projections Daniel J. Vimont University of Wisconsin - Madison Nelson Institute for Environmental Studies Center for Climatic Research University of Wisconsin - Madison Understanding Earth’s Past, Present, and Future Atmospheric and Oceanic Sciences University of Wisconsin - Madison Center for Sustainability and the Global Environment (SAGE) University of Wisconsin, Madison WAPA/WI-ASLA 2010 Annual Conference, March 4, 2010

Daniel J. Vimont Chris Kucharik (SAGE) David Lorenz, Michael Notaro, Steve Vavrus (CCR) Wisconsin Initiative on Climate Change Impacts (WICCI) Wisconsin State Climatology Office Wisconsin Focus on Energy Program Wisconsin’s Changing Climate: Recent Trends and Future Projections Daniel J. Vimont Thanks to: Chris Kucharik (SAGE) David Lorenz, Michael Notaro, Steve Vavrus (CCR) Wisconsin Initiative on Climate Change Impacts (WICCI) Wisconsin State Climatology Office Wisconsin Focus on Energy Program Nelson Institute for Environmental Studies Center for Climatic Research University of Wisconsin - Madison Understanding Earth’s Past, Present, and Future Atmospheric and Oceanic Sciences University of Wisconsin - Madison

Outline Global climate changeGlobal climate change Mitigation, adaptation, and riskMitigation, adaptation, and risk Recent climate change in WisconsinRecent climate change in Wisconsin Future climate change in WisconsinFuture climate change in Wisconsin ConclusionsConclusions

Outline Global climate changeGlobal climate change Mitigation, adaptation, and riskMitigation, adaptation, and risk Recent climate change in WisconsinRecent climate change in Wisconsin Future climate change in WisconsinFuture climate change in Wisconsin ConclusionsConclusions

Global Climate Change: Recent Trends

Global Climate Change Greenhouse Gasses: “Trap” energy in lower atmosphere Anthropogenic Greenhouse Gasses: Increasing to levels we have never seen Charles Keeling

Global Climate Change Global Temperature: Has increased by ~0.7°C over the last 100yr. The rate of increase is “accelerating”.

IPCC WG1 FAQ 1.3, Fig. 1

IPCC WG1: “Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropo- genic greenhouse gas concentrations.”

Global Climate Change: Future Projections

Global Climate Change Future Climate Change: How do we know what will happen? Global Climate Models Divide the world into boxes, solve equations that govern weather / climate on a discrete grid. Apply forcing based on a “storyline” of future emissions

Global Climate Change 2025: +1° C Emissions scenario does not matter (Adaptation) 2090: +2°-6° C Scenario does matter (Mitigation) Future Global Temperature: Temperature will increase by about 1°C in the next 20yr, 2°-6°C by the end of the century.

Outline Global climate changeGlobal climate change Mitigation, adaptation, and riskMitigation, adaptation, and risk Recent climate change in WisconsinRecent climate change in Wisconsin Future climate change in WisconsinFuture climate change in Wisconsin ConclusionsConclusions

Climate Change and Risk: Risk: Probability of an event occurring times its consequence Mitigation: Intervention to reduce the sources of greenhouse gases or enhance their sinks Adaptation: Adjustment of a system to moderate potential damages, to take advantage of opportunities, or to cope with consequences, associated with climate change

Climate Change and Risk: Risk: Probability of an event occurring times its consequence Low Probability, High Consequence High Probability, High Consequence Low Probability, Low Consequence High Probability, Low Consequence Probability Consequence Adaptation Policies Mitigation Policies

Mitigation: Necessary to avoid dangerous climate change Adaptation: Climate change is inevitable; Adaptation needed to minimize impacts Future Global Temperature: Temperature will increase by about 1.6°C in the next 40yr, 2°-6°C by the end of the century. Global Climate Change

Climate Change and Risk: Near Term Long Term Global Regional Local Adapted from: Morgot and Agrawala: The Benefits of Climate Change Policies (Ch. 1) Policy options for mitigation and adaptation involve very different scales (spatial and temporal)

Climate Change and Risk: Adaptation Benefits Reduced impact of unavoidable climate change Near Term Long Term Global Regional Local Adapted from: Morgot and Agrawala: The Benefits of Climate Change Policies (Ch. 1)

Climate Change and Risk: Adaptation Benefits Reduced impact of unavoidable climate change Mitigation: Direct Benefits Avoided climate impacts; uneven distribution; not coupled with location of mitigation Near Term Long Term Global Regional Local Adapted from: Morgot and Agrawala: The Benefits of Climate Change Policies (Ch. 1)

Climate Change and Risk: Mitigation : Ancillary Benefits (Human health, and other benefits from limiting local / regional air pollution) Adaptation Benefits Reduced impact of unavoidable climate change Mitigation: Direct Benefits Avoided climate impacts; uneven distribution; not coupled with location of mitigation Near Term Long Term Global Regional Local Adapted from: Morgot and Agrawala: The Benefits of Climate Change Policies (Ch. 1)

Mitigation in Wisconsin Governor’s Task Force on Global Warming / WCCAI Mitigation Strategy for Wisconsin: a reduction to 2005 emissions levels no later than 2014 a reduction of 22% below 2005 GHG emissions levels by 2022 a reduction of 75% from 2005 GHG emissions levels by 2050 Provides 63 suggested activities to achieve these reductions in GHG emissions

Wisconsin Initiative on Climate Change Impacts WICCI: Partnership between the UW Nelson Institute for Environmental Studies, the Wisconsin DNR, and other state groups Goal: Assess and anticipate climate change impacts on specific Wisconsin natural resources, ecosystems and regions; evaluate potential effects on industry, agriculture, tourism, and other human activities; and develop and recommend adaptation strategies…

WICCI Working Groups Water Resources Soil Conservation Agriculture Adaptation Plants & Natural Communities Central Sands Hydrology Forestry Coastal Communities Green Bay Wildlife Stormwater Coldwater Fish Milwaukee Human Health Wisconsin Climate

Outline Global climate changeGlobal climate change Mitigation, adaptation, and riskMitigation, adaptation, and risk Recent climate change in WisconsinRecent climate change in Wisconsin Future climate change in WisconsinFuture climate change in Wisconsin ConclusionsConclusions

~ ºC warmer Kucharik et al., in review

Winter T max Spring T max Summer T max Fall T max Kucharik et al., in review

Winter T min Spring T min Summer T min Fall T min The Greatest Amount of Warming is Occurring in Winter and Spring Kucharik et al., in review

Change in total days each year with T min < 0.0ºF Change in total days each year with T max > 90ºF Occurring much less frequently (6-24 days) Very little change Kucharik et al., in review

Change in Date of First Fall Freeze (32ºF) Change in Date of last Spring Freeze (32ºF) 6-20 day retreat 3-18 days later Kucharik et al., in review

Change in length of growing season (days) Increase of 1-4 weeks Kucharik et al., in review

Outline Global climate changeGlobal climate change Mitigation, adaptation, and riskMitigation, adaptation, and risk Recent climate change in WisconsinRecent climate change in Wisconsin Future climate change in WisconsinFuture climate change in Wisconsin ConclusionsConclusions

Global Climate Change Moving from Global to Regional Problem: Models are meant to reliably simulate GLOBAL climate. What regional changes can we trust? How do we translate global change into a regional context? What physical phenomena are missing?

Global Climate Change Downscaling: Focus global projections to a scale relevant to climate impacts. WICCI Climate Working Group / Focus on Energy Thanks to D. Lorenz

Needs for Downscaled Data Characterize Uncertainty Uncertainty from: large-scale model physics, emissions scenario, transition from large to small scale, additional uncertainty (from subjective assessment) High resolution (spatial and temporal) 8-10km resolution, daily time scale Need to represent extremes Extreme precipitation is necessary for hydrology; extreme temperature for human health / forestry / others FLEXIBILITY!!! Numerous potential applications, so flexibility is needed!

Global to Local Climate Change Moving from Global to Regional Downscaling Method: Downscale Probability Distribution, instead of actual variable. Advantages: PDF is large-scale, so method is “more true” to technique Extreme events are better characterized PDFs are more flexible – allows a variety of applications Work by David Lorenz - WICCI Climate Working Group / Focus on Energy

Downscaling Climate Information: ~ 4” near Stevens Point > 14” around Lake Delton

Downscaling Climate Information ~ 4” near Stevens Point > 14” around Lake Delton

Wisconsin Climate Change: Future Projections

Annual Temperature Change Wisconsin will warm by 4° – 9°F by mid- 21 st century

Winter Temperature Change Warming is most pronounced in winter: 5° – 11°F by mid-21 st century

Climate Change in Wisconsin What does it mean? Warmer Winters  Shorter Ice Duration

Climate Change in Wisconsin What does it mean? Warmer Winters  Changes in Hardiness (Invasive Species) Source: J. Williams, UW Center for Climatic Research & Department of Geography

Snow (M. Notaro) Downscaled data are used to estimate other parameters of relevance to impact assessments (e.g. annual snowfall) Notaro et al. 2010

Snowfall changes – 2055 conditions Snowfall is reduced by 20-30% by mid-century. This translates to 30-40% decrease in midwinter snow depth % Change B1 Scenario A2 Scenario Notaro et al. 2010

Climate Change in Wisconsin What does it mean? Warmer Winters  Snow cover changes Shorter Snow Season Snow Rain

Summer Temperature Change Warming is least pronounced in Summer: 3° – 8°F by mid-21 st century

Number of >90° Days, 90° Days, <0° Nights More “very hot” days, less “very cold” days

Climate Change in Wisconsin What does it mean? Warmer Summers  Reduced cold-water fish habitat; increased warm-water fish habitat Research by John Lyons, Matt Mitro, WI DNR

Winter Precipitation Change Robust increase in Winter Precipitation (0- 40%). Models do not agree on Summer: (- 20% to +15%)

Intense Precipitation Events Spring / Fall / Winter: Intense precipitation events become a little more intense

Photo credit: Sandra McClellan, UWM, and Milwaukee Metropolitan Sewage District

Outline Global climate changeGlobal climate change Mitigation, adaptation, and riskMitigation, adaptation, and risk Recent climate change in WisconsinRecent climate change in Wisconsin Future climate change in WisconsinFuture climate change in Wisconsin ConclusionsConclusions

Conclusions: Global climate is changing Carbon Dioxide levels in the atmosphere are rising due to anthropogenic emissions Earth has warmed by about 0.7 °C over the last century Most of the warming is “very likely” due to anthropogenic increases in greenhouse gasses It is very likely that earth will warm 2-6 °C over the next century Mitigation AND Adaptation are needed to reduce risk from future climate changes

Conclusions: The Wisconsin Initiative on Climate Change Impacts (WICCI) is assessing climate change impacts in Wisconsin: Wisconsin has warmed by 1°-2°F since 1950 Wisconsin will warm by 4°-9°F by mid-21 st century Snow cover and snowpack will be reduced by the mid-21 st century Winter precipitation will increase by 0%-40% by mid- 21 st century Heavy precipitation events will intensify by mid-21 st century, especially during Fall, Winter, and Spring

Wisconsin Initiative on Climate Change Impacts WICCI: Partnership between the UW Nelson Institute for Environmental Studies, the Wisconsin DNR, and other state groups Goal: Assess and anticipate climate change impacts on specific Wisconsin natural resources, ecosystems and regions; evaluate potential effects on industry, agriculture, tourism, and other human activities; and develop and recommend adaptation strategies…

Resources: Wisconsin Initiative on Climate Change Impacts Climate Working Group Interactive Website UW Atmospheric and Oceanic Sciences Nelson Institute for Environmental Studies Center for Climatic Research Center for Sustainability and the Global Environment Intergovernmental Panel on Climate Change

Sources: Mauna Loa CO2 curve: Image created by Robert A. Rohde / Global Warming Art, Charles Keeling Image: c/o Scripps Institution for Oceanography, Historical and future temperature change and Greenhouse Effect: IPCC WG1, Climate Model Schematic: June, 2008 Flood Event: Midwest Regional Climate Center, IPCC WG1 SPM: