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The Decline of Atmospheric free Oxygen
Since we have begun to measure in 1989, there has been a steady decline of free oxygen in our atmosphere. And while this is nothing more than expected, since every molecule of additional carbon dioxide locks up two oxygen atoms, the free oxygen decline is greater than the carbon dioxide lock-up.
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The greater than expected overall free oxygen decline is proof that the Earth's photosynthetic capacity has declined. And since there has been no measurable decline in plankton, and consequently, in marine photosynthesis, as long expected and measured due to the increase of hard UVB radiation at surface level, the decline points straight at the only other source of free oxygen - the forests and green cover of the continents.
This is entirely as I had fully expected and predicted (see
ON THE RECORD in the climate section) - based upon the law of Progressive Complexity. However, in 1985 there were no indications whatsoever of any decline in the free oxygen content of our atmosphere, and my initial predictions were dismissed out of hand. Here then are three graphs from "Seasonal and interannual variations in atmospheric oxygen and implications for the global carbon cycle", by Ralph F Keeling & Stephen R. Shertz, at the National Center for Atmospheric Research, Boulder, Colorado, as published in "Nature", Aug. 27. 1992.
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Taken at La Jolla, California, the upper curve shows the decline in atmospheric oxygen, and the lower curve shows the increase in atmospheric carbon dioxide over the period from January 1989 to January 1992. The axes are scaled (5 per meg=1p.p.m. so that the two factors are directly comparable (mol O2 to mol CO2). Most significantly, the observed annual (as opposed to seasonal) decline in atmospheric oxygen at La Jolla is about double the rate as would be expected from carbon dioxide lock-up alone. |
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| Taken at Cape Grim in the Southern hemisphere, the overall atmospheric free oxygen decline is an astonishing 95 times greater than expected from the increase in carbon dioxide (~96 per meg versus ~ 1 p.p.m). This is also as fully expected since most of the continental landmass by far - and the free oxygen regeneration capacity of their forests - lies in the northern hemisphere. The free oxygen decline in the northern hemisphere will begin to match that of the southern hemisphere as the forests of the northern hemisphere are further decimated. |
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Taken at Alert Bay, in the arctic circle of Northern Canada. The large dips and peaks of the seasonal variations in the northern hemisphere closely match the seasonal variation caused by the cessation of free oxygen regeneration by the deciduous component of terrestrial forests over the winter months. In the southern hemisphere, the seasonal dips and peaks of atmospheric free oxygen are caused primarily by the seasonal flux and flow of marine photosynthesis, and the temperature-driven seasonal up welling and down draft of cold water.
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