"We are particularly worried about the Greenland ice sheet because we believe that it will melt even if the temperature stays at a 2°C increase. This would ultimately give rise to a 5m sea level rise, and once its started to go it might be impossible to stop it," says Polar scientist Dr Emily Shuckburgh of the British Antarctic Survey.
What do we mean by conditions on the earth conducive to life? Life has existed on the earth before oxygen supported human and other eukaryotic life. We have discovered life that not only lives when it is hot, really hot; and there is no oxygen, but it actually thrives under those extreme conditions.
"About 55 million years ago a geological situation released more than a TERRATON of gaseous carbon and there was a warming where temperatures in the arctic and temperate regions were elevated 8 degrees C. In the tropical regions the rise was only around 5 degrees C. To return to suitable; that is conducive temperatures took over a hundred thousand years. Another-words, it doesn't take much to push the Earth into a temperature zone where (most) life can no longer sustain itself." [Nutrition Reporter - Paleolithic Nutrition: Your Future Is In Your Dietary Past]
"Earth has also been changed and unable to HEAL as it once could due to the extensive land taken for agriculture to feed and shelter the billions of people which are now inhabiting the planet and the sun has become hotter so conditions are even less fit for life. As the planet warms MOST life will die." (ibid)
So, those advancing the theory of Gaia, like James Lovelock and Lynn Margulis are telling us the Earth has a fever. Fever is not always such a bad thing. Even us; humans and other life contain within our bodies the original anaerobic archaebacteria that once lived separately billions of years ago and still does, billions of years ago and today in hot thermal deep ocean vents - the oldest life that we have discovered on Earth.
Archaebacteria consumes inorganic chemicals as their nutrition and their energy and they excrete out oxygen as waste, which is also lethal to anaerobic organisms. It was this build-up of oxygen which changed the atmosphere of the Earth, filling it with that toxic gas - because oxygen is a killer; it is a lethal toxin. AND some of that archaebacteria evolved a fitness wall around them to protect against the lethality of oxygen. It was this same lethal oxygen gas which formed a shield against the dangerous ultraviolet rays of the sun which made possible the survival of bacteria which emerged from water and from mineral deposits and which then proliferated all over the Earth. It was that archaebacteria and that bacteria which formed endosymbiotic relationships with eukaryotic cellular organisms which eventually led to complex life and humans - and other complex multicellular animals and plants.
The Earth's atmosphere was changed by the oxygen waste of archaebacteria from its very low oxygen of about 1% to it's current level of about 21%. The consequence of this change has been all forms of life on the planet, including ocean or marine life forms, plants, animals, humans, fungi but will climate change not turn the atmosphere back to a low oxygen state and cause the extinction of complex multicellular life to what it was before. Will bacteria again survive on Earth in a free independent state. Will anaerobic bacteria survive again on the Earth as they once did?
If you traced your ancestry all the way back it would be those anaerobic bacteria which are your earliest ancestors and they will survive even and WHEN humans do not.
How quick does life bounce back once it extinguishes itself? There is an evolutionary "speed limit" and life does appear to come back. It has before but bio-diversity recovers slowly relative to our measure of time in human terms, but perhaps not so long in evolutionary and earth time. But it does appear to come back; to rerun and some times even to repeat itself. Time recapitulates. Even extinction is not always forever.
Obviously, extinction is forever as far as we are concerned; as far as the "self" is concerned. Our importance is only as important as we make it. Life has been an ongoing process. Life reconstitutes itself from the atoms from which it is made, from star stuff and from fusion of hydrogen, from super novas and other upheavals which is the real generator of change and autopoiesis.
And there has been millions of years of life on this planet. There has been continuous bust outs of life after extinctions with an emergence of new organisms.
A National Science Foundation (NSF) funded study by Dr James Kirchner from the University of California at Berkeley which appeared in the journal Nature which suggested that the bounce back or recovery from a massive extinction would take longer than it would take for our species to recover. Our species would be gone forever.
OK, so when didn't we know the bio-diversity would be slow to recover after an extinction?
The science is well established that human activities is a major factor in the acceleration of global warming.
We are carbon based organisms and there is a lot of dead bodies still buried in mother Earth - a lot more than has been so far recovered as carbon based fossil fuel.
Hank Roth
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Today is Saturday February 04, 2012
