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Climate change Thursday, 16 November, 2000, 17:16 GMT
Viewpoint: Get off warming bandwagon
Currents BBC
Changes in ocean currents may cause global warning
By Professor William M Gray of Colorado State University

As a boy, I remember seeing articles about the large global warming that had taken place between 1900 and 1945. No one understood or knew if this warming would continue. Then the warming abated and I heard little about such warming through the late 1940s and into the 1970s.

In fact, surface measurements showed a small global cooling between the mid-1940s and the early 1970s. During the 1970s, there was speculation concerning an increase in this cooling. Some speculated that a new ice age may not be far off.

Then in the 1980s, it all changed again. The current global warming bandwagon that US-European governments have been alarming us with is still in full swing.

Not our fault

Are we, the fossil-fuel-burning public, partially responsible for this recent warming trend? Almost assuredly not.

These small global temperature increases of the last 25 years and over the last century are likely natural changes that the globe has seen many times in the past.


Human kind has little or nothing to do with the recent temperature changes

William M. Gray
Colorado State University
This small warming is likely a result of the natural alterations in global ocean currents which are driven by ocean salinity variations. Ocean circulation variations are as yet little understood.

Human kind has little or nothing to do with the recent temperature changes. We are not that influential.

There is a negative or complementary nature to human-induced greenhouse gas increases in comparison with the dominant natural greenhouse gas of water vapour and its cloud derivatives.

It has been assumed by the human-induced global warming advocates that as anthropogenic greenhouse gases increase that water vapour and upper-level cloudiness will also rise and lead to accelerated warming - a positive feedback loop.

It is not the human-induced greenhouse gases themselves which cause significant warming but the assumed extra water vapour and cloudiness that some scientists hypothesise.

Negative feedback

The global general circulation models which simulate significant amounts of human-induced warming are incorrectly structured to give this positive feedback loop.

Their internal model assumptions are thus not realistic.

Carbon dioxide BBC
Mainstream opinion believes that pollution contributes to climate change
As human-induced greenhouse gases rise, global-averaged upper-level atmospheric water vapour and thin cirrus should be expected to decrease not increase.

Water vapour and cirrus cloudiness should be thought of as a negative rather than a positive feedback to human-induced - or anthropogenic greenhouse gas increases.

No significant human-induced greenhouse gas warming can occur with such a negative feedback loop.

Climate debate has 'life of its own'

Our global climate's temperature has always fluctuated back and forth and it will continue to do so, irrespective of how much or how little greenhouse gases we put into the atmosphere.

Although initially generated by honest scientific questions of how human-produced greenhouse gases might affect global climate, this topic has now taken on a life of its own.

It has been extended and grossly exaggerated and misused by those wishing to make gain from the exploitation of ignorance on this subject.

This includes the governments of developed countries, the media and scientists who are willing to bend their objectivity to obtain government grants for research on this topic.

I have closely followed the carbon dioxide warming arguments. From what I have learned of how the atmosphere ticks over 40 years of study, I have been unable to convince myself that a doubling of human-induced greenhouse gases can lead to anything but quite small and insignificant amounts of global warming.

The author is a professor of atmospheric science at Colorado where he is an expert in tropical meteorology.


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