The real deal?
Against the grain: Some scientists deny global warming exists
February 02, 2007
Astrophysicist Nir Shariv, one of
Step One Scientists for decades have postulated that increases in carbon dioxide and other gases could lead to a greenhouse effect.
Step Two As if on cue, the temperature rose over the course of the 20th century while greenhouse gases proliferated due to human activities.
Step Three No other mechanism explains the warming. Without another candidate, greenhouses gases necessarily became the cause.
Dr. Shariv's digging led him to the surprising discovery that there is no concrete evidence -- only speculation -- that man-made greenhouse gases cause global warming. Even research from the Intergovernmental Panel on Climate Change-- the United Nations agency that heads the worldwide effort to combat global warming -- is bereft of anything here inspiring confidence. In fact, according to the IPCC's own findings, man's role is so uncertain that there is a strong possibility that we have been cooling, not warming, the Earth. Unfortunately, our tools are too crude to reveal what man's effect has been in the past, let alone predict how much warming or cooling we might cause in the future.
All we have on which to pin the blame on greenhouse gases, says Dr. Shaviv, is "incriminating circumstantial evidence," which explains why climate scientists speak in terms of finding "evidence of fingerprints." Circumstantial evidence might be a fine basis on which to justify reducing greenhouse gases, he adds, "without other 'suspects.' " However, Dr. Shaviv not only believes there are credible "other suspects," he believes that at least one provides a superior explanation for the 20th century's warming.
"Solar activity can explain a large part of the 20th-century global warming," he states, particularly because of the evidence that has been accumulating over the past decade of the strong relationship that cosmic- ray flux has on our atmosphere. So much evidence has by now been amassed, in fact, that "it is unlikely that [the solar climate link] does not exist." ….
….. Even doubling the amount of CO2 by 2100, for example, "will not dramatically increase the global temperature," Dr. Shaviv states. Put another way: "Even if we halved the CO2 output, and the CO2 increase by 2100 would be, say, a 50% increase relative to today instead of a doubled amount, the expected reduction in the rise of global temperature would be less than 0.5C. This is not significant."
