When I was a lad in high school, we had an annual science fair. Any entry to the fair had to be governed by the discipline of Scientific Method or it wasn’t even considered. If the AGW crowd has ever presented evidence based on Scientific Method, I have been unable to find it. I’m pretty sure that none exists because the only argument (false argument at that) they can agree on is “consensus” and I don’t believe that science is determined at the ballot box.
You are quite correct. The arguments and conclusions of the AGW crowd are not based on the Scientific Method but instead lie entirely within the realm of Pseudo-Science.
A working definition of Pseudo-Science comes from Karl Popper's Theory of Demarcation. In it, Popper defines Induction as a process by which conclusions are based upon a series of supporting observations. However, Popper goes on to argue (I'm paraphrasing here) that a truckload of evidence can be found to support virtually any hypothesis, yet a single contrary observation is sufficient to prove the hypothesis false. Therefore, conclusions based on Induction have no place in proper Science and are, instead, the nature of Pseudo-Science.
True Science is based upon the concept of falsifiability: A hypothesis (however formed) must be able to predict at least one non-trivial observable. If the result of the observation is contrary to the prediction of the hypothesis, then the hypothesis is false. This is the fundamental principle of the scientific Method.
What this means is that evidence of warming is not evidence of human-caused warming. It is merely evidence of warming. The only proper scientific way to test AGW is to test its non-trivial predicted observables. In this regard, the AGW hypothesis has failed miserably.
For example, greenhouse gas theory predicts the temperature trend in the tropical troposphere should be increasing at a rate 3 to 4 times faster than the surface rate. Observations show the opposite. The surface trend outpaces the troposphere trend by 2 or 3 times.
Furthermore, greenhouse gas theory predicts radiation into space should decrease as the surface temperature increases (because of certain positive feedback processes integrated into the theory). But observations sow radiation to space increasing by a factor of about three times the amount that greenhouse gas theory predicts it should be decreasing.
Proper Science, by these simple examples prove that global temperature is not driven by greenhouse gases.
Interestingly, the source article on which this topic is based refers to Inductive Science as Proper Science. That is totally backwards! Inductive Science is Pseudo Science. Induction plays a role only in the formation of a hypothesis, never as proof.
Sadly it is, and always has been to a certain extent.