Thursday, October 9, 2014

Climatic Changes

Thoughts

  1. Is there any hint of glacial cycles or change of temperature in the Quran?
  2. Figs and olives, mentioned in the Quran, do they have anything special with regards to their evolution?
  3. The general Western view has been that humans have had a negative impact on earth and the environment. The call has been for attempting to reduce or neutralize, if ever possible, the harmful effect humans have on the environment. The Islamic view, as it shows in the Quran, has a different perspective. The Quran sees humans as either destroyers or carers and reformers. Islam advocates the latter. The Islamic view therefore is that humans not only can reduce or neutralize their negative impact on earth and the environment but can, and should, through their actions, enhance and maintain such environment to become even better!
  4. It would be cool if I pay a visit to the tropics! I feel a deep connection to such places.
  5. I should go live and teach (ecology) in Sudan!
  6. I am against the author's view of historic accidents and that plants are not well adapted to their environments.
  7. The lush vegetation that had been present in place of the current deserts in Egypt at the time of Ancient Egyptians, were they a result of climatic cycles? Was their disappearance manmade or natural?
  8. Does the concept of succession, popular in permaculture, have anything to do with the succession of plants and their evolution with time in a particular geographical location?

Digest

  • "Changes in climate have occurred on shorter timescales than the movements of land masses."
  • "Much of what we see in the present distribution of species represents phases in a recovery from past climatic shifts."
  • "Changes in climate during the Pleistocene ice ages ... bear a lot of the responsibility for the present patterns of distribution of plants and animals."
  • Technology for discovering, analyzing and dating biological remains is becoming more sophisticated particularly by the analysis of buried pollen samples.
  • "Techniques for the measurement of oxygen isotopes in ocean cores indicate that there may have been as many as 16 glacial cycles in the Pleistocene, each lasting for about 125,000 years."
  • "Each glacial phase lasted for 50,000 to 100,000 years, with brief intervals of 10,000 to 20,000 years when the temperatures rose close to those we experience today."
  • "During the 20,000 years since the peak of the last glaciation, global temperatures have risen by about 8°C."
  • "The rate at which vegetation has changed ... has been detected by examining pollen records."
  • Sequence of trees invading:
  • Forests expand as glaciers retreat! Forests are still expanding till this day!
  • Impact on much smaller space and time scales takes place when high discharge events (associated with storms or snow melt) result in a very small-scale mosaic of patches.
  • "The stream fauna may rarely achieve an equilibrium between flow disturbances."
  • Similar changes also show up in Asia, Africa and South America.
  • "Particular ‘hot spots’ of species diversity are likely sites of forest refuges during the glacial periods, and sites of increased rates of speciation."
  • "Global warming, maybe 3°C in the next 100 years, is predicted to result from continuing increases in atmospheric carbon dioxide."
  • The extinction of the Picea critchfeldii tree in the Quaternary occurred around 15,000 years ago at a time of especially rapid postglacial warming.
  • "Even more rapid change in the future could result in extinctions of many additional species."
Glacier melting
Glacier melting

Questions

  1. Is the current rise in global temperature really attributed to manmade activities or is it just a natural oscillation of temperature inline with temperature variation cycles like those that have been occurring in the distant past?
  2. What effect has repeated climatic change had in the distant past on species and what role has it played, if any, in their evolution?