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 Is climate change really on the horizon?
The Queen gave a speech about climate change on her state visit to Germany recently. Should the world be concerned about climate change or simply continue to research it?
Neil Britten wrote:
I see the BBC has lost no time in going on the offensive against the new Bush administration over Global Warming. I listened with interest to the interview this morning between John Humphrys and an American guest who was sceptical of the Global Warming agenda. He is right to be - see below:
The problem with Global Warming
The thesis concerning global warming can be summarised as
There is conclusive evidence that the global climate is warming to an exceptional degree The rate of warming can be shown to be exceptionally high and accelerating in the 20th century Therefore man-made activities must be at fault Man made activities involve the release of abnormal quantities of Carbon Dioxide into the atmosphere and therefore Carbon Dioxide is a pollutant Carbon Dioxide is the most significant "Green house" gas Thus man-made contributions to excess Carbon Dioxide in the atmosphere are causing a dramatic increase in global temperatures due to the Greenhouse effect "Climatologists" have proved that this dramatic increase is going to continue A dramatic increase in global temperatures will have catastrophic effects
It is routinely asserted that this thesis has been proved and that a "scientific consensus" exists to justify extreme policy measures to "combat" Global Warming and Climate Change.
I started out my enquiries believing that 1 and 2 were correct and prepared to be persuaded by the science on the balance. I was a concerned citizen wanting to understand more.
My own research has persuaded me that there are problems with the Global Warming thesis. My conclusions are based on extensive readings of published peer reviewed scientific papers and data recorded by some of the most well respected research institutions in the world. (This information is available to anyone who cares to look).
My conclusions can be summarised as:
There may be a trend toward higher global temperatures than we have been used to over recently recorded history, but the data is conflicting and inconclusive, because Some surface temperature records show warming trends Some significant other, especially atmospheric records show cooling trends The atmospheric records have been subject to intense scrutiny to try to remove their "anomalous" apparent cooling trends. The surface temperature records, despite plausible explanations that might explain a warming bias, have not been subject to the same degree of rigorous examination
There is no credible evidence for an exceptional rate of warming in the 20th century. The most widely referenced source for such evidence (the famous "hockey stick" referred to by the IPCC, published in an article in Nature in 1998) has been comprehensively shown to be in error. Nature has since been obliged to publish a corrigendum to the original article. Between 1940s and 1970s average global surface temperatures fell.
Very reliable temperature records show global temperature variations of higher magnitude and rate of change in the pre-industrial era than have been experienced at any time since industrialisation (according the Central England Temperature record of the Hadley Centre for Climate Prediction and Research, between the 1690s and the 1730s average temperatures rose by 2 deg. C. This compares with the "catastrophic" 0.6 deg C rise in global average surface temperatures claimed by the IPCC). Obviously such "naturally" occurring variations in the past cannot have been caused by man-made CO2 emissions. There must be other explanations for these variations.
The man-made quantities of CO2 emitted to the atmosphere are a very small proportion of the naturally occurring exchanges of CO2 between the land biomass and the oceans. Even the IPCC's own estimate put the man-made contribution at no more than c3.5% of this natural cycle. Since the natural cycle is poorly understood it is possible that the size of CO2 exchanges with the atmosphere could vary significantly. The man-made exchanges could be less than the margin of error in the natural cycle. Also there are credible scientific arguments (including some from individuals with impeccable environmental credentials) and reliable data from botanical research that increases in the CO2 release to the atmosphere are countered by increased CO2 capture by plant growth. In any event it is absurd to consider CO2 as a pollutant (any more than water is -see 5).
It may technically correct to refer to CO2 as the most significant greenhouse gas, but it is false to conclude that it is the most significant determinant of greenhouse effect warming. That is also influenced by aerosols (air born particles) of which water vapour is the most powerful. Water vapour is an order of magnitude more influential on greenhouse warming than CO2. The mechanisms by which clouds and cloud formation influences longer-term global temperatures are poorly understood. Given their importance we cannot dismiss these effects.
The sun is the source of the net positive heat energy balance of the planet. This is demonstrably true by observations of the changes in temperatures over the seasons. The effect of the sun on longer-term global temperatures is sometimes characterised as the "solar constant". However there is no solar constant, maybe a "solar average" would be a better term. The effect of 10-11 year cyclical variations in the sun's emission of thermal and other radiation on the planet's climate is poorly understood. However there are scientifically plausible explanations of how variations in solar activity affect global climate, and in some cases, excellent correlation with observed effects. If correct, these would also explain pre-industrial era variations that the Global Warming thesis cannot under any circumstances do.
"Climatologists" use General Circulation Models (GCMs) to predict global climate trends. These are computer simulations that use mathematical models of natural processes to try to simulate reality. Such models are valuable tools in many branches of science and the fact that "climatologists" use them should not be held against the models as such. There are two problems however: Firstly, the natural processes being modelled are intrinsically extremely complex and very poorly understood. In mathematical terms the processes are non-linear. In practice this means they are highly sensitive to the initial conditions fed into the model. The level of understanding of the natural processes involved severely inhibits our ability to build, let alone use GCMs with confidence. Mathematical models are normally validated by being shown to be reliable predictors of past events using known data. Only when such models have been validated can they be used with confidence. It is a fact that no GCM has been validated. In other words none of them has been shown to be a reliable predictor of past climate using known data.The GCMs relied upon to forecast dramatic rises in global temperatures also predict that rises in atmospheric temperatures should precede rises in surface temperatures. If surface temperatures are increasing then exactly the reverse appears to be true.
We have reliable records that show regular and quite dramatic periods of cooling. These periods are known to have catastrophic effects. We also have reliable records that show dramatic periods of warming. These are not known to have produced catastrophic effects. In general, greenhouse warming is benign. Without the warming effect of greenhouse gases and aerosols the average global temperature would be so low as to prohibit much of life on the planet.
So in summary, for the Global Warming thesis to be correct:
- - The planet would have to be warming up and it is unclear that is, but if it is
- - The rate of warming must be accelerating and there is no good evidence that is, but if it is
- - CO2 must be the cause and there is no good and reliable evidence that it is, but if it is
- - Man-made CO2 must be significantly influencing the atmospheric balance of CO2 and there is no good evidence that is, but if it is
- - GCMs are reliable predictors, and they are not, but if they were
- - Warming will prove catastrophic, but there is no good evidence that it will be, but if it is
- - Then we're doomed unless we take draconian action.
If you are prepared to take on faith all six of the "ifs" above then you believe in Global Warming. I can't and I don't think our policy makers should.
That's the problem I have with Global Warming. Of course, I may be wrong. I am prepared to accept that if the Global Warming advocates are too!
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