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zankaon
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Based upon the retreat of glaciers worldwide, and opening of the Arctic ocean, and Greenland's hastened dissolution, global atmospheric warming would seem to be with us. But has there been any global oceanic warming? None yet definitively detectable by thermal expansion of the oceans (i.e. proxy of sea surface rise). http://en.wikipedia.org/wiki/Sea_level_rise"
NATURE'S PAST EXPERIMENT
An experiment of nature on the effect of intense global warming has already occurred in the Eocene 38-55 million yrs. ago; the so-called Paleocene-Eocene Thermal Maximum (PETM).(1) There were no massive extinctions comparative to that of Cretaceous-Tertiary (K-T) period defining Mezozoic/Cenazocic eras at 65Myrs. At the Paleocene-Eocene divide, paleo-stratigraphic results show that there was deep water benthic foraminifera mass extinction associated with the increased temperature and hence dysoxic (less oxygenated) waters.(1) But most marine and terrestrial extinctions occurred with cooling at the end of the Eocene, and into the Oligocene epoch.(1) The consequences of the present warming are unknown in regards to extinctions. However nature already has conducted one experiment in regards to intense global warming, with seemingly not overwhelming catastrophic results.
1. Hallam Tony, Catastrophes and Lesser Calamities Oxford Univ Press, 2004, and references therein.
Other sources consulted.
2. Raup David M., Extinction: Bad Genes or bad Luck?, W.W. Norton, 1991, and references therein.
3. Stanley Steven M., Extinction, Scientific American Books, 1987, and references therein.
NATURE'S PAST EXPERIMENT
An experiment of nature on the effect of intense global warming has already occurred in the Eocene 38-55 million yrs. ago; the so-called Paleocene-Eocene Thermal Maximum (PETM).(1) There were no massive extinctions comparative to that of Cretaceous-Tertiary (K-T) period defining Mezozoic/Cenazocic eras at 65Myrs. At the Paleocene-Eocene divide, paleo-stratigraphic results show that there was deep water benthic foraminifera mass extinction associated with the increased temperature and hence dysoxic (less oxygenated) waters.(1) But most marine and terrestrial extinctions occurred with cooling at the end of the Eocene, and into the Oligocene epoch.(1) The consequences of the present warming are unknown in regards to extinctions. However nature already has conducted one experiment in regards to intense global warming, with seemingly not overwhelming catastrophic results.
1. Hallam Tony, Catastrophes and Lesser Calamities Oxford Univ Press, 2004, and references therein.
Other sources consulted.
2. Raup David M., Extinction: Bad Genes or bad Luck?, W.W. Norton, 1991, and references therein.
3. Stanley Steven M., Extinction, Scientific American Books, 1987, and references therein.
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