About GLOBAL WARMING

November 8, 2007
It is a sad fact of life that it are usually the loudest voices which are listened to, amplified by the media and (out of survival necessity or self interest) echoed by the politicians. In this noise the calm voice of logic and objective consideration is usually drowned out. The debate about Global warming is a clear example.

Yes, the earth is warming at present, and

Yes, CO₂ emission from human activities is increasing

But that does not necessarily mean that one is related to, let alone caused by, the other.

As a qualified and experienced former Geologist I have been very skeptical about the so called Global Warming debate. From what I have seen, read and heard in the media the evidence presented has been rather superficial and unconvincing to say the least. I wholeheartedly sympathise with Martin Durkin (maker of the documentary The Great Global Warming Swindle) when he says :

The makers of the documentary "The Great Global Warming Swindle" have made many science documentaries before. The thing they found most shocking when they started to make this one, was the weakness of the case for man made global warming, and the quantity and quality of the evidence which flatly contradicts it.

From a geological perspective the present temperature variations are well within the natural range covering the earth's history as far as we know it.
Here is a graph (from the Global Petition Website of the Oregon Institute of Science & Medicine) showing the Sea surface temperature variations in the Sargasso Sea (region in the Atlantic ocean) over the past 3,000 years.

The temperatures were determined by isotope ratios of marine organism remains in sediment at the bottom of the sea.

The horizontal line is the average temperature for the past 3,000 years.
Temperatures over this period have varied within a 3 degrees Celsius range.

The Medieval Climate Optimum is the most recent naturally occurring high, when Greenland was indeed green and its climate much enjoyed by the Vikings at the time,

and the Little Ice Age around 1500 is the most recent natural low, from which we still are recovering at the present time.

The graph shows that we are at present near the 3,000 year average, but also suggests that temperatures may well rise further beyond this point into the near future.

So if not the result of human generated CO₂ emissions, what is the cause of our global warming ?
Here is a (sorry, rather poor) photograph of an illustration in the Weekend Australian newspaper (August 22, 2007, Inquirer section, page 22) from an article by Martin Durkin.

Arctic temperature variations over a 120 year period (as measured by scientists from NASA and the US National and Atmospheric Administration) are superimposed :

on the left by Solar irradiance

and on the right by the increase in CO₂ levels

I am sure you can form your own opinion from that.
Interestingly the graphs also show a distinct cooling during the recent 50s and 60s, and I can still vividly remember the worries expressed in the media (near the end of this period) that we were heading for another ice age.

For more data and comments on this topic see the Global Petition Website of the Oregon Institute of Science & Medicine where 17,000 scientists have signed a petition against the man made global warming argument, and Martin Durkin's website of his documentary on The Great Global Warming Swindle.

Finally
So does this mean we should not worry about our greenhouse gas emissions ? Certainly not !
Air pollution is enormously harmful to humans and perhaps other living beings (plants however thrive on more CO2). In Australia it is estimated that 4 times more people each year die as a result of air pollution than in traffic accidents on the road. In heavily polluted countries like China, India, etc. this figure must be much much higher.

Therefore we certainly must reduce our greenhouse gas emission. But if you believe that by doing so we will reduce global warming and its inevitable effects on the world, you are probably greatly mistaken. Global warming, it appears to me, is caused by natural processes over which we as humans have very little, if any, control.

Interestingly, the people I talk to every day and from all walks of life (representing a silent majority perhaps ?), are as skeptical about the Global warming debate as I am. This I find very heartening. Common sense it appears (despite all the media hype and political posturing), is still alive and well amongst many. Thanks goodness for that !