The Bottom LineThis comes from Dr. Richard Lindzen of MIT, explaining how climate models and the IPCC's assumptions compare to actual observational data of sea surface temperatures and actual heat radiated into space.
The earth’s climate (in contrast to the climate in current climate GCMs [General Circulation Models]) is dominated by a strong net negative feedback. . . . such warming as may arise from increasing greenhouse gases will be indistinguishable from the fluctuations in climate that occur naturally from processes internal to the climate system itself. [bold added]
Climate models are all based on the IPCC-accepted assumption that there is a positive feedback loop such that with increased temperature, greenhouse gases like water vapor will respond by blocking even more heat from escaping. By this logic, adding other greenhouse gases like CO2 will only make it worse.
According to Lindzen and studies he cites, not only is this positive feedback not confirmed by observational data of heat radiation into space, the opposite is true.
Here is an easily appreciated example of positive and negative feedback. In your car, the gas and brake pedals act as negative feedbacks to reduce speed when you are going too fast and increase it when you are going too slow. If someone were to reverse the position of the pedals without informing you, then they would act as positive feedbacks: increasing your speed when you are going too fast, and slowing you down when you are going too slow.Am I a climate scientist? No. But I certainly appreciate an analysis of evidence, rather than an appeal to suspect computer models and the "settled" consensus of politically-motivated authorities.
Alarming climate predictions depend critically on the fact that models have large positive feedbacks. The crucial question is whether nature actually behaves this way? The answer, as we have just seen, is unambiguously no. [bold added]
Also, the logic of the following statement Lindzen made in a recent presentation is unassailable:
Why do we need to deconstruct global warming? Simply because it has been an issue that has been routinely treated with misinformation and sophistry abetted by constant repetition, institutional endorsements, and widespread ignorance even (perhaps especially) among the educated. Because of the increasingly dangerous and expensive approaches being promoted to deal with this alleged problem, it is, I think, important to understand what is being said as well as to understand how climate actually works.[HT: HBL]