Hello All!   
      
   The Summer of 2012 -- Too Hot to Handle?    
      
   August 3, 2012: This past June more than 170 all-time US heat records were   
   tied or broken--many of them originally set in the historically hotter months   
   of July and August. And with a drought plaguing much of the country, the   
   ground is as dry and crispy as a saltine cracker.    
      
   By early July, 56% of the contiguous U.S. was experiencing drought. That's the   
   largest percentage in the 12-year record of the U.S. Drought Monitor. Fires   
   scorched over 1.3 million acres across the US in June, reducing hundreds of   
   homes to ashes in the West.    
      
   Just imagining prospects for the rest of the summer is enough to bring sweat   
   to your brow. And last winter is partly to blame.    
      
   "799 daytime heat records were broken in the first five days of January in the   
   US," says Jake Crouch, a climate scientist from the NOAA National Climatic   
   Data Center. "Last year's was the fourth warmest winter since 1895. And it was   
   dry, with a dearth of snowfall in many places. During most of this past winter   
   and spring, a positive North Atlantic Oscillation pressure pattern kept the   
   jet stream further north and the US warmer and drier than normal."    
      
   With little moisture in the soil to evaporate and dissipate some of the sun's   
   energy, more solar radiation is converted to sensible heat, he says.    
      
   http://eoimages.gsfc.nasa.gov/images/imagerecords/78000/78394/co   
   tuslsta_tmo_20 12169_lrg.jpg   
      
   Surface temperature anomalies across the United States in June 2012. More   
   information   
   Of course global warming is on the tips of many tongues.    
      
   "CO2 is up from 280 parts per million in the 19th century atmosphere to 400   
   parts per million now -- a 43% increase," says NASA climatologist Bill   
   Patzert. "We're emitting six times more carbon from fossil fuel use now than   
   we did 50 years ago. Atmospheric CO2 hasn't been this high in 400,000 years."    
      
   Greenhouse gasses like CO2 and methane have higher heat capacities than many   
   other gasses, causing the atmosphere to retain more heat.    
      
   "The atmosphere becomes a heat source itself, radiating heat back onto the   
   Earth. 85 to 90% of that heat is absorbed by the oceans, because water has a   
   high heat capacity. So the oceans expand and rise. Global sea levels have   
   risen 8 inches over the past 130 years, and the average surface temperature of   
   the entire earth (land surface temperatures plus ocean temperatures) has   
   increased 1.6 øF. These facts," he asserts, "are unequivocal proof of global   
   warming."    
      
   But is the record-setting summer 2012 evidence of climate change?    
      
   http://en.wikipedia.org/wiki/File:Dust-storm-Texas-1935.png   
      
   Previous heat waves in the 1930s contributed to the "dust bowl" phenomenon. In   
   this picture, a dust storm approaches Stratford, Texas, in 1935. Credit: NOAA   
   George E. Marsh Album "Not necessarily," says Patzert. "We've always had   
   extreme weather. US history is written in great natural calamities --   
   tornadoes, hurricanes, heat waves, droughts, floods. Global warming is   
   happening, but it would be irresponsible to say that this heat wave and all   
   these broken records are due to global warming from human causes. It's just   
   not that simple."    
      
   John Christy, a scientist from the University of Alabama in Huntsville,   
   agrees: "Heat waves are a natural part of the climate system, and while the   
   recent heat wave was remarkable, it was not as intense as others in the past."    
      
   He offers a few examples of past heat waves and droughts.    
      
   "The central US suffered several heat waves in the 1930s -- the dust bowl   
   years -- when more statewide, all-time record high temperatures were set than   
   in any other decade. And the western US experienced decades-long droughts in   
   the 12th century. So dry were mountain areas that we can still see   
   near-hundred-year-old trees standing upright in the bottom of alpine lakes   
   where they grew on dry ground 900 years ago.1 This shows that in the 12th   
   century it was so dry and hot that the lakes dried up and allowed trees to   
   grow over a significant period before moisture finally returned."    
      
   Patzert and Christy are on opposite sides of the global warming debate.   
   Patzert firmly believes that Earth is warming up and humans are the main   
   reason why. Christy, on the other hand, argues that natural climate variations   
   are almost solely to blame. Yet they both agree that the summer 2012 weather   
   might be just that - weather. They also both believe that improvement is   
   needed in models indicating effects of human and other factors on weather and   
   climate.    
      
   "Today's climate models are extremely sophisticated, constantly improving, and   
   will be crucial to charting our future -- but they aren't perfect," says   
   Patzert.    
      
   One component that needs improvement: clouds.    
      
   "Clouds play a key role in climate because they affect the amount of sunlight   
   reflected and absorbed," says Christy. "We need higher resolution models to   
   portray them more accurately. The distance between grid measurement points in   
   current models is too great to capture meter to meter variations in clouds,   
   land cover, and other variables that affect climate."    
      
   One more point of agreement: the summer of 2012 is too hot to handle.    
      
      
   Author: Dauna Coulter| Production Editor: Dr. Tony Phillips | Credit:   
   Science@NASA   
      
   More information    
   What Happened to All the Snow? --Science@NASA    
      
   Europe Hammered by Winter; Is North America Next? -- Science@NASA    
      
   More from Crouch: "Another driver could be the La Nina which ended a few   
   months ago. When there is a La Nina, most of the nation tends to be warmer and   
   drier than average, with the exception of the Pacific Northwest. Although La   
   Nina is officially over, there is a lag in the atmosphere and La Nina like   
   conditions are still possible in the atmosphere. We provide an overview of   
   what other atmospheric drivers were likely in play for the warm June that we   
   just experienced at this website."    
      
   Footnote: (1) For an article on some of these trees, see http://   
   ww.nvwra.org/storage/newsletters/jnwra_2_article3_kleppe.pdf .     
      
      
   Regards,   
      
   Roger    
   --- timEd/386 1.10.y2k+   
    * Origin: NCS BBS - Houma, LA - (1:3828/7)