Wisconsin’s Changing Climate: Recent Trends and Future Projections Daniel J. Vimont University of Wisconsin - Madison

1. 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 Wisconsin’s Changing Climate:Recent Trends and Future ProjectionsDaniel J. VimontUniversity of Wisconsin - Madison WAPA/WI-ASLA 2010 Annual Conference, March 4, 2010

2. 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 Wisconsin’s Changing Climate:Recent Trends and Future ProjectionsDaniel J. VimontThanks to:Chris Kucharik (SAGE)David Lorenz, Michael Notaro, Steve Vavrus (CCR)Wisconsin Initiative on Climate Change Impacts (WICCI)Wisconsin State Climatology OfficeWisconsin Focus on Energy Program

3. Outline • Global climate change • Mitigation, adaptation, and risk • Recent climate change in Wisconsin • Future climate change in Wisconsin • Conclusions

4. Outline • Global climate change • Mitigation, adaptation, and risk • Recent climate change in Wisconsin • Future climate change in Wisconsin • Conclusions

5. Global Climate Change: Recent Trends

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

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

8. IPCC WG1 FAQ 1.3, Fig. 1

9. 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.”

10. Global Climate Change: Future Projections

11. 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

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

13. Outline • Global climate change • Mitigation, adaptation, and risk • Recent climate change in Wisconsin • Future climate change in Wisconsin • Conclusions

14. 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

15. Climate Change and Risk: Risk: Probability of an event occurring times its consequence Mitigation Policies Adaptation Policies Consequence Probability

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

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

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

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

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

21. 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

22. 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… http://www.wicci.wisc.edu

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

24. Outline • Global climate change • Mitigation, adaptation, and risk • Recent climate change in Wisconsin • Future climate change in Wisconsin • Conclusions

25. ~0.5-1.0ºC warmer Kucharik et al., in review

26. Spring Tmax Summer Tmax Fall Tmax Winter Tmax Kucharik et al., in review

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

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

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

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

31. Outline • Global climate change • Mitigation, adaptation, and risk • Recent climate change in Wisconsin • Future climate change in Wisconsin • Conclusions

32. 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?

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

34. 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!

35. 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

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

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

38. Wisconsin Climate Change: Future Projections

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

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

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

42. 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

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

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

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

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

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

48. 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

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

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