2024-02-07

Denying the Catastrophe: The Science of the Climate Skeptic's Position

"It is important to begin by emphasizing that few skeptics doubt or deny that carbon dioxide (CO2) is a greenhouse gas or that it and other greenhouse gasses (water vapor being the most important) help to warm the surface of the Earth. Further, few skeptics deny that man is probably contributing to higher CO2 levels through his burning of fossil fuels, though remember we are talking about a maximum total change in atmospheric CO2 concentration due to man of about 0.01% over the last 100 years.

What skeptics deny is the catastrophe, the notion that man's incremental contributions to CO2 levels will create catastrophic warming and wildly adverse climate changes. To understand the skeptic's position requires understanding something about the alarmists' case that is seldom discussed in the press: the theory of catastrophic man-made global warming is actually comprised of two separate, linked theories, of which only the first is frequently discussed in the media.

The first theory is that a doubling of atmospheric CO2 levels (approximately what we might see under the more extreme emission assumptions for the next century) will lead to about a degree Celsius of warming. Though some quibble over the number – it might be a half degree, it might be a degree and a half – most skeptics, alarmists and even the UN's IPCC are roughly in agreement on this fact.

But one degree due to the all the CO2 emissions we might see over the next century is hardly a catastrophe. The catastrophe, then, comes from the second theory, that the climate is dominated by positive feedbacks (basically acceleration factors) that multiply the warming from CO2 many fold. Thus one degree of warming from the greenhouse gas effect of CO2 might be multiplied to five or eight or even more degrees.

This second theory is the source of most of the predicted warming – not greenhouse gas theory per se but the notion that the Earth's climate (unlike nearly every other natural system) is dominated by positive feedbacks. This is the main proposition that skeptics doubt, and it is by far the weakest part of the alarmist case. One can argue whether the one degree of warming from CO2 is "settled science" (I think that is a crazy term to apply to any science this young), but the three, five, eight degrees from feedback are not at all settled. In fact, they are not even very well supported...

Despite these heroic efforts to try to find observational validation for their catastrophic warming forecasts, the evidence continues to accumulate that these forecasts are wildly overstated."



https://www.forbes.com/sites/warrenmeyer/2010/10/15/denying-the-catstrophe-the-science-of-the-climate-skeptics-position/?sh=639399591c66

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