A Warming, a Warning, and a Caveat Steve Vavrus Center for Climatic Research University of Wisconsin-Madison

Recent Precipitation Trends (Madison)

U.S. CCSP, 2008

Figure A Warming... IPCC (2007)

Figure IPCC (2007) A Warming...

A Warning... Projected Changes in Extreme Precipitation IPCC (2007)

(wettest day)(10th wettest day) Rank Large increase in very heavy precipitation over southern Wisconsin More Extreme Precipitation Events

Future Return Periods of Modern 20-year Heavy Precipitation Events Late 21st Century vs. Late 20th Century U.S. CCSP, 2008

Courtesy of Dan Vimont Regional Downscaling of Climate Model Projections Global Climate Model (coarse)Downscaled Model Results (fine)

Fewer light events More heavy events Vavrus and Van Dorn, 2008 Downscaled Climate Model Projections (Chicago)

U.S. CCSP, 2008

Change in Wisconsin temperature and precipitation predicted by 15 climate models ( minus ). (The average model change is shown by the thick black line.) Courtesy of Dave Lorenz A Caveat...

19 Climate ModelsMeasured

A Caveat Climate ModelsMeasured Summer Maximum (75%)Spring and Autumn Maxima

Projected Downscaled Precipitation Changes (Chicago) Vavrus and Van Dorn, 2008

Projected Downscaled Precipitation Changes (Chicago) Vavrus and Van Dorn, 2008

Projected Spring Precipitation Change

L H Projected Spring Circulation Change

Conclusions Significant warming expected in all seasons Greater total precipitation in Wisconsin (winter, spring) Summer precipitation changes are much less certain Shift toward more heavy precip events, fewer light events Enhanced extremes associated with more moisture in air Modeled changes in mean, extreme precip very similar Observed trends show more heavy precip events (MSN) Climate models still being evaluated wrt extreme precip

Wisconsin Initiative on Climate Change Impacts (WICCI)

Partnership between UW, DNR and other state agencies and institutions

Form working groups of experts to focus on specific issues Assess potential climate change impacts on natural and human systems Develop adaptation strategies that can be used by decision makers in local government, public health, business, etc. WICCI goals:

Will respond to Advisory Committee input to address issues or questions of most concern to stakeholders

Climate of Wisconsin Stormwater management Human health Milwaukee Green Bay watershed Northern forests Coldwater fisheries Wildlife habitat Eight Working Groups So Far:

More information: 82 Science Hall 550 N. Park Street Madison, WI Phone: (608)

Late 21st-Century Projections of Hydrology Changes Precip. Runoff Soil Moisture Evap. IPCC (2007)

Probability of Snow vs. Rain Courtesy of Dan Vimont