Shepard Glacier-2005 Glacier National Park, Montana

Transcription

1 To help protect your privacy, PowerPoint prevented this external picture from being automatically downloaded. To download and display this picture, click Options in the Message Bar, and then click Enable external content. 9/23/2010 Explaining to the Mass Audience Visual Evidence Glenn Schwartz Chief Meteorologist NBC10 Philadelphia Shepard Glacier-1913 Glacier National Park, Montana Shepard Glacier-2005 Glacier National Park, Montana Comparison ph 1

2 Arctic Ice Cover Changes Arctic Ice Cover Changes Arctic Ice Cover Changes Feb. Arctic Sea Ice Age But the scariest picture of all 2

3 To help protect your privacy, PowerPoint prevented this external picture from being automatically downloaded. To download and display this picture, click Options in the Message Bar, and then click Enable external content. To help protect your privacy, PowerPoint prevented this external picture from being automatically downloaded. To download and display this picture, click Options in the Message Bar, and then click Enable external content. 9/23/2010 Debate Used to be About Science Now It s About Politics The Debate Rages Bastardi: winter snowstorms prove global warming hoax Washington Times: February Snow Storms Undermine the Case for One Flake at a Time -OR- More Mega-Snowstorms Coming -- Global Warming to Blame? Get used to heavy U.S. snowstorms, scientists say. Are we scaring our children? From a child who is yet to lose all her baby teeth: "I worry about [global warming] because I don't want to die." Back to the Science One out of three children aged 6 to 11 fears that Ma Earth won't exist when they grow up, 75 percent of black children and 65 percent of Hispanic children believe that the planet will be irrevocably damaged by the time they reach adulthood. Greenhouse Effect Atmosphere is transparent to incoming solar radiation Outgoing Longwave infrared radiation is trapped by greenhouse gasses The most dominant greenhouse gas is water vapor Changes in the composition of the atmosphere interfere with these energy flows Mauna Loa Monthly Mean Carbon Dioxide

4 Evidence in Ice Cores World Carbon Emission Present 4

5 To help protect your privacy, PowerPoint prevented this external picture from being automatically downloaded. To download and display this picture, click Options in the Message Bar, and then click Enable external content. 9/23/2010 North America Carbon Emission Present Past 1000 Years ( Hockey Stick Graph ) Present Controversial Another Study Past 2000 Years Controversial jpg p g Great Graphics Globalwarmingart.com Earth s Temperature Changes Evidence from Weather Instruments 5

6 It s Warming Again! Global Temperature Changes Past 10 Years Winter Temp Change Summer Temp Change Hindcasting Past 100 Years Computer Models 6

7 Forecasting Next 100 Years Is Abrupt Climate Change Possible? Greenland Ice Sheet Flows Accelerating Since 1996 Accelerates Glacier Sliding May be much faster than Computer Models Indicate Can Further Melting Result in Large Sea Level Rises in 100s of years instead of 1000s of years? Temperature Change Forecast Lower End is significant High End is catastrophic Middle Area is most likely Even that is MAJOR Sea Level Rise Forecast Lower End causes storms to flood more Higher End floods coastal cities A Response to Skeptics Questions Middle End is most likely statistically More rapid rise is possible 7

8 It s All Because of the Sun Actual Temperature Trend The Warming Ended in 1998 The Warming Ended in 1998 That was a Strong El Nino year that added to the warming 2005 about as warm, but had no El Nino to Skew the data In the 70s they said an ice age was coming 8

9 In the 70s they said an ice age was coming This was more in the popular media than the scientific articles A book by a non-scientist called The Cooling became a best-seller But it was NOT the prevailing scientific view at the time (I was there) Even the National Geographic and Newsweek suggested the possibility of warming due to CO2 in the future It was just as warm in the Medieval warm period as today Medieval Warm Period It was just as warm in the Medieval warm period as today Maybe it was warmer in Europe, but there s no evidence that it was that warm worldwide This is GLOBAL warming, not regional Ice core records show that CO2 increase comes AFTER the warming. So does warming increase CO2? Vostok Ice Core Records 9

10 Does warming increase CO2? Warming did start about 800 years before CO2 increase Some other forcing (Milankovich) started the warming Warming oceans release CO2 CO2 then causes temp to rise, which causes more CO2 (feedback!) CO2 could be stored in deep ocean during ice ages, and then released when warmed We can not explain temperature variations WITHOUT CO2 Why are the Antarctic ice sheets growing? Why are the Antarctic ice sheets growing? It doesn t have to warm everywhere Ice sheet thickens due to more snow due to warming We Can t even predict the weather next week. How can we predict 100 years? How can we predict 100 years? Climate vs. weather Averaging over time removes random nature We can predict tomorrow with near 90% accuracy, and computer models of the atmosphere are the main reason why Testing models by going back and predicting up to today is pretty good (the trends are right) The computer models already proven to be too warm 10

11 Hansen Forecasts and Actual Computer models too warm 3 scenarios from IPCC. Middle one is doing well Models correctly predicted cooling of stratosphere Models correctly predicted big warming of arctic Models correctly predicted oceans to warm Models correctly predicted cooling rate due to volcanic eruptions Models don t take clouds into account Climate models don t take clouds into account ALL models DO take clouds into account The type of clouds is very important and there is uncertainty Some places are cooling; others have record cold days. Doesn t that disprove it? Cooling and record cold disprove? The whole earth doesn t warm uniformlysome places will cool But there are MANY more record highs than record lows around the world 11