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Scientists who believe cause of global warming is unknown December 19, 2007

Posted by globalwarmingscare in Scientists who believe cause of global warming is unkno.
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Scientists who believe cause of global warming is unknown

Scientists in this section conclude it is too early to ascribe any principal cause to the observed rising temperatures, man-made or natural.

  • Syun-Ichi Akasofu, retired professor of geophysics and Director of the International Arctic Research Center of the University of Alaska Fairbanks: “[T]he method of study adopted by the International Panel of Climate Change (IPCC) is fundamentally flawed, resulting in a baseless conclusion: Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations. Contrary to this statement …, there is so far no definitive evidence that ‘most’ of the present warming is due to the greenhouse effect. … [The IPCC] should have recognized that the range of observed natural changes should not be ignored, and thus their conclusion should be very tentative. The term ‘most’ in their conclusion is baseless.”[48]
  • Claude Allègre, geochemist, Institute of Geophysics (Paris): “The increase in the CO2 content of the atmosphere is an observed fact and mankind is most certainly responsible. In the long term, this increase will without doubt become harmful, but its exact role in the climate is less clear. Various parameters appear more important than CO2. Consider the water cycle and formation of various types of clouds, and the complex effects of industrial or agricultural dust. Or fluctuations of the intensity of the solar radiation on annual and century scale, which seem better correlated with heating effects than the variations of CO2 content.”[49]
  • Robert C. Balling, Jr., a professor of geography at Arizona State University: “[I]t is very likely that the recent upward trend [in global surface temperature] is very real and that the upward signal is greater than any noise introduced from uncertainties in the record. However, the general error is most likely to be in the warming direction, with a maximum possible (though unlikely) value of 0.3 °C. … At this moment in time we know only that: (1) Global surface temperatures have risen in recent decades. (2) Mid-tropospheric temperatures have warmed little over the same period. (3) This difference is not consistent with predictions from numerical climate models.”[50]
  • John Christy, professor of atmospheric science and director of the Earth System Science Center at the University of Alabama in Huntsville, contributor to several IPCC reports “I’m sure the majority (but not all) of my IPCC colleagues cringe when I say this, but I see neither the developing catastrophe nor the smoking gun proving that human activity is to blame for most of the warming we see. Rather, I see a reliance on climate models (useful but never “proof”) and the coincidence that changes in carbon dioxide and global temperatures have loose similarity over time.”[51]
  • William R. Cotton, Professor of Atmospheric Sciences at Colorado State University said in a presentation, “It is an open question if human produced changes in climate are large enough to be detected from the noise of the natural variability of the climate system.”[52]
  • Chris de Freitas, Associate Professor, School of Geography, Geology and Environmental Science, University of Auckland: “There is evidence of global warming. … But warming does not confirm that carbon dioxide is causing it. Climate is always warming or cooling. There are natural variability theories of warming. To support the argument that carbon dioxide is causing it, the evidence would have to distinguish between human-caused and natural warming. This has not been done.”[53]
  • David Deming, geology professor at the University of Oklahoma: “The amount of climatic warming that has taken place in the past 150 years is poorly constrained, and its cause–human or natural–is unknown. There is no sound scientific basis for predicting future climate change with any degree of certainty. If the climate does warm, it is likely to be beneficial to humanity rather than harmful. In my opinion, it would be foolish to establish national energy policy on the basis of misinformation and irrational hysteria.”[54]
  • Richard Lindzen, Alfred P. Sloan Professor of Atmospheric Science at the Massachusetts Institute of Technology and member of the National Academy of Sciences: “We are quite confident (1) that global mean temperature is about 0.5 °C higher than it was a century ago; (2) that atmospheric levels of CO2 have risen over the past two centuries; and (3) that CO2 is a greenhouse gas whose increase is likely to warm the earth (one of many, the most important being water vapor and clouds). But–and I cannot stress this enough–we are not in a position to confidently attribute past climate change to CO2 or to forecast what the climate will be in the future.”[55] “[T]here has been no question whatsoever that CO2 is an infrared absorber (i.e., a greenhouse gas — albeit a minor one), and its increase should theoretically contribute to warming. Indeed, if all else were kept equal, the increase in CO2 should have led to somewhat more warming than has been observed.”[56]
  • Roy Spencer, principal research scientist, University of Alabama in Huntsville: “We need to find out how much of the warming we are seeing could be due to mankind, because I still maintain we have no idea how much you can attribute to mankind.”[57]