Thursday, August 31, 2006

AAPG Position on Global Warming

A few caveats to begin with:

First of all, I am not a member of the AAPG (American Association of Petroleum Geologists). I used to be, from around 1980 to 1996. One of the reasons I discontinued membership was that the association did not desire to be seen to be political and I felt this was detrimental to the profession. As it turns out, I think I was right, in that, by ignoring the politics of science the AAPG gave the upper hand to others who now basically control the media. Coming into the fray at this late stage is definitely going to be an uphill struggle.

Because I am not a member, I should not have access to some of the information that I am using in this entry. However, the members' only data is already freely circulating on the internet and it contains some fine material in graphic form that really demonstrates the problems we are facing in getting the true message across about global warming. As many of the graphics are drawn from the public domain, I feel it is OK to reproduce those graphics here.

The actual document the AAPG has published on the internet for all to see is dry, factual and not something that will ever impress the media. So bear with me on this, when I give you the link. By the way, do consider downloading the Word document, it reads well and can easily be attached to an e-mail!

So. To begin.

This graph is based on data gathered from atmosphere trapped in Antarctic ice and sampled from core. Note the span of human civilization is very small compared with 400,000 years of data. Note also the very large CO2 and temperature swings during the four Ice Ages. Basically, we can easily infer from this that the "massive increases in CO2 and rising temperature" that drives the modern climate change debate are nothing by comparison with natural history.

These graphs and the selected straight line trends derived from them show that scientists and politicians can very easily use fundamental data to whatever advantage they feel necessary. The data reflect carbon 18 isotope measurements from Greenland and Antarctic ice cores and these directly relate to temperatures at the time the carbon was trapped in the ice. Five trends have been drawn using various segments of the data.
Trend 1 uses the entire 16,000 years of data gathering and shows a general upward increase in temperature, as should be expected as we in an inter-glacial period, emerging from the last great Ice Age.
Trend 2 uses the period from 10,000 before present (BP) to the present and shows a gradual decline in temperature.
Trend 3 focuses on the most recent 2,000 years and this confirms Trend 2. Both these lines could be interpreted (by comparison with the 400,000 year chart above) that we entered a cooling trend about 10,000 years ago and that we may already be heading toward a fifth great Ice Age!
Trend 4 now looks only at the past 700 years and here the data is inconclusive, temperature appears to be quite stable within a relative narrow range of up and down spikes.
Trend 5 mirrors what we like to perceive as the era of rapidly changing human civilization - the past 50 years. The slight upward rise in temperature could be significant if taken without context to what has happened before but in fact there are been far greater swings in temperature that could only have resulted from purely natural events.

The big scary "fact" we are bombarded with is that increasing CO2 in the atmosphere is directly related to climate change. Yet this graph suggests that there is no real correlation between temperature changes observed in recent history and the increasing amount of CO2 in the atmosphere. If anything, temperature changes take on a distinct cyclical appearance through time in contrast with the rising levels of CO2.

So what does cause the temperature changes? Look no further than the sun, our neighborhood star. When more heat arrives on the surface of the planet, the temperature rises! Heat variations from the sun may be due to a number of causes, including sunspot activity, changes in the axis of rotation of the Earth and variations in the elliptical axis of the Earth's orbit.

With all this emphasis on increasing CO2 and the greenhouse gas effect, it is interesting to note just how important CO2 really is and, when the human element is separated from natural CO2 causes, just how insignificant the entire anthropogenic global warming debate is.

Finally, the AAPG document notes that, without the greenhouse effect we basically couldn't exist and that any small changes we are now experiencing are likely to have a positive effect (side note: totally validating the title of this blog!) in that in most parts of the globe rising temperatures and increasing CO2 concentrations would have a tremendous positive effect on plant and crop growth.


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