NOAA Climate Communications WorkshopMay 6, What can we say about our changing climate and trends in extreme events? Wayne Higgins, Ph.D. Acting Director, NOAA National Weather Service National Centers for Environmental Prediction May 2013

NOAA Climate Communications WorkshopMay 6, Outline Part 1: The Demand for Useable Information on Extremes Part 2: Observed & Projected Trends in Extremes Key Issues: Temperature Precipitation Coastal Vulnerability Part 3: Take Away Messages

NOAA Climate Communications WorkshopMay 6, The Demand for Useable Information on Extremes PART ONE

NOAA Climate Communications WorkshopMay 6, Extremes matter Changes in weather and climate extremes have profound impacts and consequences. Rising Demand for Information Compelling scientific evidence shows that the nature of extreme events is altered by climate variations and change. Decision makers are demanding improved information on how changes in climate may influence future extremes. Also want to know about potential impacts a changing climate and extremes may have on our lives, livelihoods, businesses and the ecological systems that support us. Disasters Snowstorms/ Blizzards Tornadoes Wildfires Hurricanes & Tropical Storms Floods Geophysical Heat waves Droughts Source: NOAA Climate Adaptation Portfolio Weather & Climate Extremes

NOAA Climate Communications WorkshopMay 6, Heat-Trapping Greenhouse Gases are Increasing Pre industrial levels: ~280 ppm; Current levels: ~396 ppm; Current rate of increase: ~1.9 ppm/yr Concentrations today far exceed the natural range over the last 650,000 years Source:

NOAA Climate Communications WorkshopMay 6, Global Temperatures are Increasing Global surface temperatures have increased about 1.5°F ( 0.8°C) since ~1900. Average U.S. surface temp. has risen +0.13°F per decade since 1901 and has increased to °F per decade since the late 1970s. The warming has not been uniform. Some areas have cooled slightly. The recent warmth has been greatest over North America and Eurasia. Source: National Climatic Data Center

NOAA Climate Communications WorkshopMay 6, The Earth is Warming Source: National Climatic Data Center

NOAA Climate Communications WorkshopMay 6, Natural Disasters are on the Rise Source:

NOAA Climate Communications WorkshopMay 6, The Nation Is Weather/Climate Conscious… for Good Reason Drought and Heat Waves Hurricanes and Tropical Storms Winter Storms and Crop Freezes FloodingWildfiresSevere Local Storms Source: National Climatic Data Center U.S. Billion-Dollar Weather and Climate Disasters: 1980 – 2011

NOAA Climate Communications WorkshopMay 6, PART TWO Observed & Projected Trends in Extremes

NOAA Climate Communications WorkshopMay 6, Key Issue: Temperature Changes in trends of maximum and minimum temperatures Changes in “normal” distribution of temperatures

NOAA Climate Communications WorkshopMay 6, Observed: Increasing Temperatures Statewide changes in annual “normal” temperatures ( compared to ) Source: Maximum Minimum

NOAA Climate Communications WorkshopMay 6, Observed: Temperature Extremes More unusually warm days and nights in recent decades Fewer unusually cold days and nights Increasing number of heat waves, but 1930s still most severe

NOAA Climate Communications WorkshopMay 6, Projected: Temperature Extremes Warm days and nights, and heat waves - very likely more frequent. Cold days and cold nights – very likely much less frequent. Days with frost – very likely to decrease.

NOAA Climate Communications WorkshopMay 6, Key Issue: Precipitation Changes in precipitation patterns and intensity Changes in drought frequency, intensity, and duration Changes in snowpack Changes in precipitation type (e.g., rain vs. snow)

NOAA Climate Communications WorkshopMay 6, Observed: Precipitation Extremes Percent of the U.S. with much above normal 1-day heavy precipitation (>2 inches) A statistically significant increase in extremes since the late 1970s NOAA U.S. Climate Extremes Index Annual (Jan-Dec)

NOAA Climate Communications WorkshopMay 6, Observed: Precipitation Extremes Source: Percent increases in the amount of precipitation falling in very heavy events (defined as the heaviest 1% of all daily events) from 1958 to There are clear trends toward a greater amount of very heavy precipitation for the nation as a whole, and particularly in the Northeast and Midwest.

NOAA Climate Communications WorkshopMay 6, Projected: Precipitation Extremes Source: Lightest precipitation is projected to decrease. Heaviest precipitationis projected to increase strongly. Higher greenhouse gas emission scenarios produce larger changes in extreme precipitation.

NOAA Climate Communications WorkshopMay 6, Key Issue: Coastal Vulnerability Sea-level change Increasing Storm Intensity Storm Surge & Flooding

NOAA Climate Communications WorkshopMay 6, Observed: Sea Level Rise Source: Based on NOAA Sea Level Trends data Tide gauges confirm that global sea level has risen ~0.07 inches per year since 1880 (i.e., ~ 8 inches ) Since 1993, satellites confirm that sea level has risen roughly twice as fast as the rate over the last century

NOAA Climate Communications WorkshopMay 6, Projected: Sea Level Rise Projecting future rates of SLR is challenging Model projections suggest ~ 1– 4 ft is plausible by 2100 Where risk tolerance is low, some decision makers may wish to use ~8 in to 6.6 ft by 2100 Scientists continue to work to improve models

NOAA Climate Communications WorkshopMay 6, Observed: Hurricanes in the Atlantic Basin No clear trend in numbers of hurricanes since 1878 Changes in observation methods make it difficult to identify long- term trends Hurricane strength has increased since 1980s Six of the 10 most active years have occurred since the mid- 1990’s

NOAA Climate Communications WorkshopMay 6, Projected: Hurricanes in the Atlantic Basin The intensity of the strongest hurricanes is projected to continue to increase as the oceans continue to warm Other storm trends --e.g. numbers of hurricanes, tornadoes, hail, thunderstorms, etc. -- are uncertain and being studied Source:

NOAA Climate Communications WorkshopMay 6, Current State of Scientific Knowledge Widely varying – depends on suitability of our data and physical understanding of various extreme events Positive correlation between detection and understanding

NOAA Climate Communications WorkshopMay 6, Demand for Climate Information is Increasing Across Space and Time Scales NOAA and other agencies are working to provide a suite of products from near term forecasts to long term projections, tailored to stakeholders’ needs.

NOAA Climate Communications WorkshopMay 6, Take Away Messages PART THREE

NOAA Climate Communications WorkshopMay 6, Take Away Messages Observed and Projected trends – Heavy downpours are increasing in most regions of the U.S.; the largest have been in the Midwest, southern Great Plains, and Northeast. – Heat waves have been most prevalent in the West; droughts in the Southwest and heat waves everywhere projected to become more intense – Global sea level rise projected to rise another 8” to 6.6 ft. by 2100, with local variations. – Stronger hurricanes in the North Atlantic expected as the ocean warms Projecting local scale impacts are difficult – Regional scales of projections frustrate local decision makers. NOAA & partners are working to improve delivery of useful information to support a variety of decisions – Links between trends in green-house gas concentrations and some types of extremes, including hurricanes, tornadoes, and snowstorms have not been fully established, but remain active areas of research. – Credible extrapolation of trends (other than for gross features of the climate) depends on improved understanding and future model improvements.

NOAA Climate Communications WorkshopMay 6, Questions?