Smart and Sustainable CampusesApril 16, Modern Climate Change: Where have we been and where are we headed? Thomas R. Karl, L.H.D. Director, National Climatic Data Center Chair, U.S. Global Change Research Program April 2013

Smart and Sustainable CampusesApril 16, ©Warren Faildey -Weatherstock.comrOutline Motivation – Billion-dollar Disasters – U.S. Climate Extremes Index Past and Future Climate – Temperature – Heat and Cold Waves – Precipitation/flooding and drought – Snowstorms – Tornadoes

Smart and Sustainable CampusesApril 16, NOAA’s National Climatic Data Center (NCDC): Where are we? Who are we? What do we do? 160 Federal Employees ̶Alaska, Colorado, Hawaii, Maryland, Missouri, New York, North Carolina, Texas, Utah, Wisconsin 153 NCDC Headquarter Contractors 6 Regional Climate Centers 2 Cooperative Institutes Protecting the Past… Revealing the Future NCDC Headquarters

Smart and Sustainable CampusesApril 16, The Nation Is Climate-Conscious… for Good Reason U.S. Billion-Dollar Weather and Climate Disasters: 1980 – 2011 Drought and Heatwaves Hurricanes and Tropical Storms Winter Storms and Crop Freezes FloodingWildfiresSevere Local Storms NOAA’s National Climatic Data Center

Smart and Sustainable CampusesApril 16, U.S. Climate Extremes Index Includes measures of: – Wetness/drought – Extreme precipitation – Dry/wet days, extremes – Extreme temperature – Hurricanes The 2012 U.S. Climate Extremes Index value of is the 2nd- largest of the metric’s period of record (since 1910)

Smart and Sustainable CampusesApril 16, Current State of Scientific Knowledge Series of four workshops/papers for BAMS  Monitoring and Understanding Changes in Extreme Storm Statistics: State of Knowledge. Kunkel, K.E. et al., 2012, BAMS.  Monitoring and Understanding Changes in Heat Waves, Cold Waves, Floods and Droughts in the United States: State of Knowledge. Peterson, T.C. et al., 2013, BAMS.  Monitoring and Understanding Changes in Extreme Winds, Waves, and Extratropical Storms along the Coasts: State of Knowledge. Vose, R.S. et al., in review BAMS.  CMIP5 Climate Model Analyses: Climate Extremes in the United States. Wuebbles, D., et al., in review BAMS

Smart and Sustainable CampusesApril 16, What’s Driving the Increase Since the 1970s? Extremes in Maximum Temperature All graphs are based on annual data Extremes in Minimum Temperature Drought Severity and Water Surplus Drought Severity and Water Surplus Extremes in 1-Day Heavy Precipitation NOAA U.S. Climate Extremes Index a.gov/extremes/cei/

Smart and Sustainable CampusesApril 16, “Loaded Climate Dice” compared to – Doubled likelihood of a hot month (red shading) compared to (a) – Almost 10% chance of what used to be a 1 in 1000 year event ( ) (b) All Stations (Northern Hemisphere Land – Summer) Limited Stations (Northern Hemisphere Land – Summer) Based on Hansen, J. et al., 2012 aa bb

Smart and Sustainable CampusesApril 16, Standardized monthly temperature anomalies 9 Maximum temps – Highly significant trend at national scale – Weak trend in drought regions – 2012 spring/summer was about a one in 1600-year event in a stationary climate Minimum Temps – Highly significant trend at national scale and drought regions – 2012 spring/summer was about a one in 450-year event in a stationary climate Karl et al., EOS 2012 Maximum Temps Minimum Temps U.S. Spring and Summer

Smart and Sustainable CampusesApril 16, Heat Wave Index for the U.S. Shows the number of 4-day intervals exceeding a threshold for a 1 in 5-yr recurrence. Updated from Kunkel et al BAMS

Smart and Sustainable CampusesApril 16, Heat Waves and Cold Waves Peterson, T. C. et al., Monitoring and Understanding Changes in Heat Waves, Cold Waves, Floods and Drought in the United States: State of Knowledge. BAMS. Standardized 4-day heat/cold wave index by decade.

Smart and Sustainable CampusesApril 16, Change in number of very hot days All regions are projected to have an increase in the number of very hot days The hottest climates are projected to add over a month (30+ days) of days over 90 Hot days have impacts on human health, air quality, energy use, and agriculture. Model studies indicate that intense heat waves that now occur once every 20 years are projected to occur about every other year in much of the country by the end of this century (Karl et al., 2009)

Smart and Sustainable CampusesApril 16, Change in number of very cold days All regions projected to be less cold Some regions projected to lose 20+ days per year below freezing Impacts on freezing of lakes, human health, energy use, agriculture

Smart and Sustainable CampusesApril 16, Intensified Water Cycle Adapted from National Climate Assessment unpublished work

Smart and Sustainable CampusesApril 16, Day Heavy Precipitation Events Percent of the U.S. with much above normal 1-day heavy precipitation Annual (Jan-Dec) A statistically significant increase in extremes NOAA U.S. Climate Extremes Index

Smart and Sustainable CampusesApril 16, Precipitable Water Difference (Percent) Difference between minus for daily, 1-in-5-year extreme events Peterson, T. C. et al., 2013.

Smart and Sustainable CampusesApril 16, Changes in Heavy Precipitation The total amount of precipitation falling on days that exceed the 99th percentile threshold of daily precipitation amounts during the 30-yr period of with respect to the prior 30-yr period of The differences are expressed as percent of the values.

Smart and Sustainable CampusesApril 16, Maximum Daily Precipitation Most places projected to have higher maximum daily precipitation Kunkel et al GRL

Smart and Sustainable CampusesApril 16, Extreme Precipitation: Projected Future Trends Potential Maximum Precipitation likely to increase with increases in atmospheric water vapor due to warming oceans and increased evaporation Change in Precipitation Intensity Adjusted for future water vapor trends Adjusted for recent water vapor trends Currently used in PMP Potential Maximum Precipitation NOAA/NCDC

Smart and Sustainable CampusesApril 16, Trends in Flooding and Precipitation Regional similarities between trends of annual precipitation, droughts, and extremes of river flooding River-Flow Trends in Annual Maximum: years ending 2008 River-Flow Trends in Annual Maximum: years ending 2008 Trends in Total Annual Precipitation: Peterson, T. C. et al., 2013.

Smart and Sustainable CampusesApril 16, U.S. Drought of 2012 Karl et al, 2012 EOS From MODIS data. Courtesy of I. Becker-Reshef, E. Vermote, M. Claverie and C. Justice, University of Maryland. Illinois

Smart and Sustainable CampusesApril 16, Drought Widespread persistent drought – 1930s (Central and Northern Great Plains, Northwest, Great Lakes) – 1950s (Southern Plains, Southwest), 1980s (West, Southeast) – First decade of the 21st century (West, Southeast) Trends (% per century) 1900 to 2011: -0.1% 1930 to 2011: -10.0% 1971 to 2011: +31.6% Peterson, T. C. et al., 2013.

Smart and Sustainable CampusesApril 16, Projected Change (A2 Scenarios – “Higher Emissions”) in North American Precipitation (Late 21st Century) 15 Climate Models Global Climate Change Impacts in the United States, Thomas R. Karl, Jerry M. Melillo, and Thomas C. Peterson, (eds.). Cambridge University Press, 2009.

Smart and Sustainable CampusesApril 16, Projected Change in Standardized Precipitation Index Simulated difference (%) in the number of months with a Standardized Precipitation Index (SPI) value of less than -1, for the time period with respect to the reference period of for a high (SRES A2) emissions scenario.

Smart and Sustainable CampusesApril 16, Historical Drought The percent area of the western half of the United States experiencing mild to extreme drought (Palmer Drought Severity Index ≤ -1.0) from (graph at top), reconstructed from tree ring data, smoothed with a 60-year spline (heavy line) and a 20- year (light line). Droughts earlier in the paleoclimatic record (some years ago) were much more severe and extensive than droughts of the 20th century. Peterson et al., 2013.

Smart and Sustainable CampusesApril 16, Extreme Snowstorms Would changes in temperature and precipitation favor more or fewer extreme snowstorms? For the top 50 snowstorms during unusually warm, cool, dry and wet seasons, it varies: – E.g. Southern Plains much snowier when cool – Northern Plains much snowier when wet NOAA’s National Climatic Data Center

Smart and Sustainable CampusesApril 16, Tornadoes & Convective Storms Although some ingredients that are favorable for severe thunderstorms have increased over the years, others have not Overall, changes in the frequency of environments favorable for severe convective storms have not been statistically significant Kunkel, K.E., et al., BAMS. Squires, M.F. et al., unpublished work

Smart and Sustainable CampusesApril 16, Summary Widely varying suitability of our data and physical understanding of various extreme events Positive correlation between detection and understanding

Smart and Sustainable CampusesApril 16, Questions?