2007 IPCC Results: Implications for Georgia

1. 2007 IPCC Results: Implications for Georgia J. Marshall Shepherd, Ph.D Research, Meteorologist and Associate Professor of Atmospheric Sciences and Geography

2. “I have put our nation on a path to slow, stop, and eventually reverse the growth of our greenhouse gas emissions. …….Our new 2025 goal marks a major step forward in America's efforts to address climate change.”--President G.W. Bush, White House Speech, April 16 2008 The issue of climate change is one of the greatest challenges that our generation faces.--Sen. Barack Obama, http://obama.senate.gov/issues/environment “…I can tell you this. I have had enough experience and enough knowledge to believe that unless we reverse what is happening on this planet, my dear friends, we are going to hand our children a planet that is badly damaged.”--NY Times, Oct. 2007 quoting Sen. John McCainat the Global Warming and Energy Solutions Conference http://mccain.senate.gov/public/ The scientific consensus on climate change is increasingly clear: unless we act to reduce emissions of carbon dioxide and other greenhouse gases, the planet will continue to warm over the next century, with widespread and potentially devastating effect--Sen. Hillary Clinton http://clinton.senate.gov/issues/environment/index.cfm?topic=climate 2007 IPCC Report--90% Certainty Heralds a New Reality, New Discourse

3. Georgia’s Has Been Cooling, So No Global Warming, Right? GA Analogue: Is Home Depot stock a good representation of the Dow or S & P on a given day? Figures: State Climatologist ad IPCC

4. What are IPCC Scenarios? Courtesy: IPCC A1: a future world of very rapid economic growth, global population that peaks in mid-century and declines thereafter, and rapid introduction of new and more efficient technologies. (Subsets--A1FI - An emphasis on fossil-fuels, A1B - A balanced emphasis on all energy sources, A1T - Emphasis on non-fossil energy sources) A2: a very heterogeneous world with continuously increasing global population and regionally oriented economic growth that is more fragmented and slower than in other storylines. B1: a convergent world with the same global population as in the A1 storyline but with rapid changes in economic structures toward a service and information economy, with reductions in material intensity, and the introduction of clean and resource-efficient technologies. B2: a world in which the emphasis is on local solutions to economic, social, and environmental sustainability, with continuously increasing population (lower than A2) and intermediate economic development.

5. IPCC 2007 --90% Certainty Human Contributions Will Continue to Warm the Earth System Which Model Scenario is closest to the real response?

6. IPCC General Projections

7. Climate Change and An Accelerating Water Cycle? • Changes in water cycle most perceptible to society: drought, floods, hurricane, vector-borne disease, sea level rise, agriculture

8. Is the Water Cycle Accelerating? Satellites now record space-time variability of precipitation over decades GPCP While global trends do not appear to exist for precipitation, GPCP products indicate that regional trends do occur. Courtesy R. Adler/NASA

9. Grid Resolution of GCMs are too coarse Weather models much smaller so get closer to resolving processes Water bodies and land surface heterogeneity poorly resolved or not resolved Tropical Cyclones Not Explicitly Resolved Aerosol (e.g. pollution) and Clouds???? Capturing Dynamic Process and Climate Variability (e.g. El Nino) Other Unresolved Processes and Feedbacks Before Interpreting IPCC Impacts on Georgia, Caution!!!! UGA/NASA-Columbia/EdGCM

10. Georgia’s Climate Variability vs Climate Change During the last Ice Age, Georgia probably experienced a climate somewhat wetter and cooler than we have today. Models indicate that the average annual rainfall was about 63 inches and the annual average temperature was 56.3º F, compared with modern values of 51 inches and 63.5º F. Georgia’s climate varies on many different time scales, from seasonal to multi-decadal. These variations are due to a number of factors, including ocean temperatures, land use changes, and weather and climate events happening elsewhere in the US and the world. Asst. state climatologist/P. Knox

11. Georgia climate trends Cooling in the last 50 years, but some signs of reversal in last 10 years…. Since 1895, Georgia’s rainfall has varied from one year to the next, but there is only a very slight trend towards higher precipitation over the last century Recent drought is apparent in NASA Precipitation data for North GA (below) State Climatologist and Shepherd et al. 2008

12. What Georgia Should Expect? Annual Winter Summer Temperature Change Precipitation Change IPCC, 2007

13. Southeast US Projected to See Increases in Extreme Events! Extreme Heat: Implications For Health, agriculture, energy sector Diffenbaugh et al. 2005 Water Cycle Acceleration?

14. Del Genio et al. (2007) suggested that warmer land and higher freezing levels due to global warming could lead to stronger (but fewer) severe storms in the future. Climate Change-Severe Weather Link? N. GA. Tornadoes (1950-2006). from Shepherd et al. (2008)

15. North America has experienced substantial social, cultural, economic and ecological disruption from recent climate related extremes, especially storms, heatwaves and wildfires Continuing infrastructure development, especially in vulnerable zones, will likely lead to continuing increases in economic damage from extreme weather The vulnerability of North America depends on the effectiveness of adaptation and the distribution of coping capacity, both of which are currently uneven and have not always protected vulnerable groups from adverse impacts of climate variability and extreme weather events A key prerequisite for sustainability is ‘mainstreaming’ climate issues into decision making. Climate change will exacerbate stresses on diverse sectors in North America, including, but not limited to, urban centers, coastal communities, human health, water resources and managed and unmanaged ecosystems. Indigenous peoples of North America and those who are socially and economically disadvantaged are disproportionately vulnerable to climate change IPCC Summary Relevant to Georgia

16. Georgia’s Climate Change Not Only CO2 Related! For example: Atlanta’s urbanization may be altering the water cycle, air quality, temperature Mote, Lacke, and Shepherd 2007

17. From the Headlines---- Global warming may exacerbate ozone the most in already-polluted areas. Jacobson (2007, GRL) -----CO2 may increase U.S. annual air pollution deaths by about 1000 (350–1800) and cancers by 20–30 per 1 K rise in CO2-induced temperature.