TCS Daily


The Chimera of Carbon Dioxide Increase

By William Kininmonth - October 15, 2004 12:00 AM

It never fails to amaze how the media gullibly makes every piece of greenhouse gas trivia into a feeding frenzy about global warming. A claim currently making the international media rounds is that for the past two years carbon dioxide levels in the atmosphere have been increasing at an annual rate greater than two parts per million (ppm). This is to be compared with previous rates of about 1.5 ppm, and described as a cause of concern. One report (The Australian, 13/10) closes with "A further fear is that extra human emissions ... may be blunting the planets ability to absorb carbon dioxide -- which, in the worst scenario, could lead to runaway warming".

If this sort of reading is what regularly accompanies breakfast, it is no wonder that susceptible members of the community are racked by depression, turning to drugs for escape, or constipated from fear!

The sad fact of the matter is that the little gem of reporting is no more than speculation based on statistical spin. Some relevant numbers have been collated and interpreted for the media as something alarming. The truth is much more prosaic.

Monthly and annual values of carbon dioxide concentration for ten global sites are available from the Carbon Dioxide Information Analysis Center at the Oak Ridge National Laboratory, USA. Two sites are in close proximity at Hawaii. The difficulty of maintaining an ongoing observation program can be judged from the three sites that have seriously incomplete records and not suitable for intercomparison. Nevertheless, there are six well-distributed sites extending from the Arctic to the Antarctic with long and nearly complete records of atmospheric carbon dioxide concentration.

Notwithstanding the media claim, the increase in concentration from 2001 to 2002 exceeded 2.0 ppm at only two of the six stations. The average of all stations exceeded 2.0 ppm but only because of an unexplained large increase at the South Pole site, far from centres of industrialisation.

It is widely acknowledged, and borne out by data, that the year-to-year increase in concentration is greater during El Niño events, when tropical Pacific Ocean surface temperatures are unusually warm. This factor explains the larger than normal increase from 2002 to 2003. However, it should also be recognised that the annual increase to 2003 was significantly less than during the major El Niño event of 1997-98, a point lost in the media hype.

There has been an ongoing increase in carbon dioxide due to human activities but this is not the climate phenomenon of real concern. There is no Camelot climate optimum from which we are being driven by increasing carbon dioxide concentrations. The climate system, regionally and globally, is naturally varying over all timescales. Weather and climate extremes, including heat waves, ice storms, hurricanes, tornadoes, flood or drought are all manifestations of the climate system and its variations.

Weather and climate extremes will continue to severely impact on communities, unless planning and preparation, early warning, emergency response and aftermath support measures are implemented. These are real measures that can be implemented to prevent loss of life, to minimise destruction of property and infrastructure and to quickly restore livelihoods. Unfortunately, the opportunities are being largely ignored in the hysteria over anthropogenic global warming and the lemming-like chase after the chimera of greenhouse gas reductions.

William Kininmonth runs a meteorological consultancy, Australasian Climate Research.


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