XPost: alt.culture.alaska, alt.appalachian, alt.politics.democrats.d   
   XPost: soc.culture.african.american   
   From: pavley.oil@sacbee.com   
      
   There goes another Democrat fantasy down the toilet.   
      
   Permafrost in the soil and methane hydrates deep in the ocean   
   are large reservoirs of ancient carbon. As soil and ocean   
   temperatures rise, the reservoirs have the potential to break   
   down, releasing enormous quantities of the potent greenhouse gas   
   methane. But would this methane actually make it to the   
   atmosphere?   
      
   Researchers at the University of Rochester—including Michael   
   Dyonisius, a graduate student in the lab of Vasilii Petrenko,   
   professor of earth and environmental sciences—and their   
   collaborators studied methane emissions from a period in Earth's   
   history partly analogous to the warming of Earth today. Their   
   research, published in Science, indicates that even if methane   
   is released from these large natural stores in response to   
   warming, very little actually reaches the atmosphere.   
      
   "One of our take-home points is that we need to be more   
   concerned about the anthropogenic emissions—those originating   
   from human activities—than the natural feedbacks," Dyonisius   
   says.   
      
   What are methane hydrates and permafrost?   
      
   When plants die, they decompose into carbon-based organic matter   
   in the soil. In extremely cold conditions, the carbon in the   
   organic matter freezes and becomes trapped instead of being   
   emitted into the atmosphere. This forms permafrost, soil that   
   has been continuously frozen—even during the summer—for more   
   than one year. Permafrost is mostly found on land, mainly in   
   Siberia, Alaska, and Northern Canada.   
      
   Along with organic carbon, there is also an abundance of water   
   ice in permafrost. When the permafrost thaws in rising   
   temperatures, the ice melts and the underlying soil becomes   
   waterlogged, helping to create low-oxygen conditions—the perfect   
   environment for microbes in the soil to consume the carbon and   
   produce methane.   
      
   Methane hydrates, on the other hand, are mostly found in ocean   
   sediments along the continental margins. In methane hydrates,   
   cages of water molecules trap methane molecules inside. Methane   
   hydrates can only form under high pressures and low   
   temperatures, so they are mainly found deep in the ocean. If   
   ocean temperatures rise, so will the temperature of the ocean   
   sediments where the methane hydrates are located. The hydrates   
   will then destabilize, fall apart, and release the methane gas.   
      
   "If even a fraction of that destabilizes rapidly and that   
   methane is transferred to the atmosphere, we would have a huge   
   greenhouse impact because methane is such a potent greenhouse   
   gas," Petrenko says. "The concern really has to do with   
   releasing a truly massive amount of carbon from these stocks   
   into the atmosphere as the climate continues to warm."   
      
   Gathering data from ice cores   
      
   In order to determine how much methane from ancient carbon   
   deposits might be released to the atmosphere in warming   
   conditions, Dyonisius and his colleagues turned to patterns in   
   Earth's past. They drilled and collected ice cores from Taylor   
   Glacier in Antarctica. The ice core samples act like time   
   capsules: they contain tiny air bubbles with small quantities of   
   ancient air trapped inside. The researchers use a melting   
   chamber to extract the ancient air from the bubbles and then   
   study its chemical composition.   
      
   Dyonisius's research focused on measuring the composition of air   
   from the time of Earth's last deglaciation, 8,000-15,000 years   
   ago.   
      
   "The time period is a partial analog to today, when Earth went   
   from a cold state to a warmer state," Dyonisius says. "But   
   during the last deglaciation, the change was natural. Now the   
   change is driven by human activity, and we're going from a warm   
   state to an even warmer state."   
      
   Analyzing the carbon-14 isotope of methane in the samples, the   
   group found that methane emissions from the ancient carbon   
   reservoirs were small. Thus, Dyonisius concludes, "the   
   likelihood of these old carbon reservoirs destabilizing and   
   creating a large positive warming feedback in the present day is   
   also low."   
      
   Dyonisius and his collaborators also concluded that the methane   
   released does not reach the atmosphere in large quantities. The   
   researchers believe this is due to several natural "buffers."   
      
   Buffers protect against release to the atmosphere   
      
   In the case of methane hydrates, if the methane is released in   
   the deep ocean, most of it is dissolved and oxidized by ocean   
   microbes before it ever reaches the atmosphere. If the methane   
   in permafrost forms deep enough in the soil, it may be oxidized   
   by bacteria that eat the methane, or the carbon in the   
      
   [continued in next message]   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)