Climate change "science" -- not yet finished, not yet sound.
"[recent work exposes the] shakiness of the three main arguments which comprise the Intergovernmental Panel on Climate Change (IPCC) case for a human influence on climate change.
Argument one asserts that ground-based temperature measurements have been corrected adequately for environmental effects, including especially the urban "heat island" effect, and that the pattern of global change in temperature which results -- about a 0.60 C increase over the last 100 years -- is likely to have a human cause. In actuality, that part of the claimed increase in temperature which occurred over the last 20 years is contradicted by two alternative measurements of atmospheric temperature made from weather balloons and satellites, the patterns of which agree with each other and show little or no long-term trend of temperature change. At the very least, this discrepancy casts doubt on the adequacy of the heat island correction which has been made to the records.
Argument two, after papers by statistician Michael Mann and co-authors, asserts that both the peak magnitude and the rate of temperature increase over the last 100 years are exceptional by comparison with the preceding 900 years. But recent published papers by other scientists have demolished this argument and shown that Mann's work is statistically unsound; both its historical analysis and its projected peak of warming at the recent turn of the century are now known to be flawed. And anyway, irrespective of recondite statistical arguments, many earlier published geological studies show that the rate and magnitude of climate change over historic times lies within the envelope of natural variation.
The third IPCC argument rests upon complex computer models which attempt to predict the rate of warming for the increasing rate of carbon dioxide in the atmosphere through to the year 2100. However, these models are unable to simulate 20th century climatic history accurately, and also fail when tested against the last 20 years of accurate data from satellites and weather balloons. A primary reason for the mismatches is probably that the computer models assume an unrealistically high temperature sensitivity for atmospheric greenhouse gas accumulation.
The flaws in these three IPCC arguments are cumulatively fatal. But, in addition, it has become increasingly apparent lately that the 1,000-year interval which is the context for most IPCC advice and analysis is a completely inadequate period over which to assess global climate change. The focus of discussion, therefore, is shifting away from the short-term mechanisms studied by meteorologists and climatologists, to attending more to the knowledge base for climate change which exists in the geological record over tens and hundreds of thousands of years .. ". More "Climate Change: A Longer View".
Posted by Greg Ransom
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