Click to edit Master title style • • • • • Click to edit Master text styles The Changing Debate on Second level Climate Third level Fourth level Eric J. Barron Fifth level Center for Atmospheric National List of Nominations Research 1 Every credible scientist recognizes that increases in greenhouse gases promotes Click to editwarming Master title style • •“Greenhouse Gases”text are styles wavelengthClick to edit Master selective absorbers • Second level • Third level • Without selective absorbers Earth is 5 F • Fourth level Fifthselective level • •With absorbers Earth is 64 F List of Nominations 2 The Real Issues in the Debate Click to edit Master title style • How much will it warm – in response to humans adding greenhouse gases? •more Click to edit Master text styles • How fast will it warm? Second level • •How significant will be the impact? • Third level The first two questions will likely remain uncertain for decades. • Fourth level • Fifth level List of Nominations So, for decision-makers the last question is key. It is not just a science question. It depends on what you value and your sense of risk. 3 Explain that – my debate with an Click to edit Master title style economist • Suppose I got contract to cut down all of •the Click to edit Masteraround text styles trees for lumber your city. •Good Second level or bad? • Third level • Fourth level • Fifth level List of Nominations 4 Explain that – my debate with an Click to edit Master title style economist • Suppose I got contract to cut down all of •the Click to edit Masteraround text styles trees for lumber your city. •Good Second level or bad? Third level • •GOOD – a product - brings in dollars; jobs brings in dollars •- Fourth level • Fifth level List of Nominations 5 Explain that – my debate with an Click to edit Master title style economist • Suppose I got contract to cut down all of •the Click to edit Masteraround text styles trees for lumber your city. •Good Second level or bad? Third level • •GOOD – a product, brings in dollars; jobs, dollars •brings Fourthinlevel • •WAIT what about beauty, habitat, Fifth – level ecosystem services (water)? List of Nominations 6 Explain that – my debate with an Click to edit Master title style economist • Suppose I got contract to cut down all of •the Click to edit Masteraround text styles trees for lumber your city. or bad? •Good Second level • •GOOD – a product, brings in dollars; jobs, Third level brings in dollars • Fourth level • WAIT – what about beauty ,habitat, •ecosystem Fifth level services (clean water)? • In one generation they won’t know what they have missed – no value List of Nominations 7 The Changing Debate Click to edit Master title style • What do scientists really know about •global Click warming? to edit Master text styles Second • •What are level the predictions for the future? Third are level • • What the potential impacts and •vulnerabilities? Fourth level • Fifth level List of Nominations 8 Click to edit Master title style • • • • • Click to edit Master text styles What do Climate Experts Second level Really Know about Global Third level Fourth level Warming? FifthAnd, levelstep back 15 years ago to examine the predictions List of Nominations 9 ClickFoundations to edit Master title style (1995) • Carbon Dioxide is a Selective Absorber Click to edit Gases Masterare textIncreasing styles • •Greenhouse (oil, deforestation) •coal, Second level • •Increased Greenhouse Gases Promote Third level Warming • Fourth level • Draw down will take Centuries • Fifth level • Aerosols have Human Sources • Many Aerosols Promote Cooling • The Planet has warmed 1° F in Century List of Nominations 10 Global Temperatures Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 11 Cooling? Finally? Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 12 Temperature Trends Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 13 Click to edit Master title style • • • • • Click to edit Master text styles 1995: Confidence Second level Third level Predictions Fourth level Fifth level in List of Nominations 14 Predictions: Virtually Certain ClickThe to Stratosphere edit Master • 1995: will title cool style • Click to edit Master text styles • Second level Stratospheric tropical temperature • Third level trends (observations • Fourth level in blue) From Bill • Fifth level Randel List of Nominations 15 Predictions: Very Probable Click to edit Master title style • 1995: Surface Temperature will Increase in response to increased levels of greenhouse •gases Click to edit Master text styles – -- .5 to 2.0 C by 2050 • –Second level -- 1.5 to 4.5 C for end of century List of Nominations -- 2.5 Clevel most likely • –Third • Fourth level • Fifth level 16 Predictions to 2100 (IPCC) Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 17 Predictions: Very Probable Click to edit Master title style • 1995: Global Precipitation Will Increase • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 18 Spatial Changes in Precipitation Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 19 Column Water Vapor Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 20 Predictions: Very Probable Click to edit Master title style • 1995: Sea Ice will Retreat in N.H. • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations Compared to 1979-2007 mean; Richter-Menge et al. 21 Rate of Decline Greater than Click to edit Master title style Predictions • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations Boe et al. 22 Predictions: Very Probable • 1995: N.H. Latitude Warming Click toHigh edit Master title • • • • • style Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations IPCC 23 Snow Cover (IPCC) Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 24 Predictions Click to Very edit Master Probabletitle style • Click to edit Master text styles • 1995: Sea Level will Rise • –Second 5-40 cm level by 2050 • Third level • Fourth level • Fifth level List of Nominations 25 Sea Level (IPCC) Click to edit Master title style • • • • • Click to edit Master text styles Tide Gauges Second level Third level Fourth level Fifth level List of Nominations Based on A1B 26 Predictions Click to Very edit Master Probabletitle style • 1995: Solar Variability will Not be Significant •Over Clickthe to Next edit Master textCompared styles 50 years to CO2 • Second level • Third level Global Climate Change • Fourth level Impacts in the U.S. 2009 • Fifth level List of Nominations 27 ClickPredictions to edit Master title style - Uncertain • Click to edit Master text styles • Climate Variability Changes • Second level • Regional Climate Changes • Third level • Tropical Storms • Fourth level • The Next 25 Years • Fifth level • Biosphere Feedbacks List of Nominations 28 ENSO CHARACTERISTICS Click to edit Master title style OBSERVATIONS • • • • • 1o CCSM4 Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 29 Hurricane simulated in NCAR Nested Regional Model Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 30 Click to edit Master title style • Click to edit Master text styles What do Climate Models Predict? • Second level • Third level • Fourth level U.S. Centric 2090-2100 – only to • Fifthforce levelus to think about impacts List of Nominations and risk 31 Community Climate System (CCSM) Click to Model edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations Advancing Earth-system science 32 Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 33 Regional Comparisons (IPCC) Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 34 Temperatures Compared to Click to edit Master title style Prediction • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 35 US Temperature Predictions 1995 Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 36 Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations Global Climate Change Impacts in the United States, 2009 37 Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 38 Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations Global Climate Change Impacts In the United States, 2009 39 Click to edit Master title style • • • • • Click to edit Master text styles What are the Potential Impacts Second level for Ecosystems, Water, Third level Agriculture and Health? Fourth level Many interesting areas: Fifth level Consider only Ecosystems List of Nominations 40 Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 41 Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations 42 Click to edit Master title style • • • • • Click to edit Master text styles Second level Third level Fourth level Fifth level List of Nominations Global Climate Change Impacts in The United States, 2009 43 The Changing Debate Click to edit Master title style • What do scientists really know about •global Click warming? to edit Master text styles Second • •What are level the predictions for the future? Third are level • • What the potential impacts and •vulnerabilities? Fourth level • Fifth level List of Nominations 44