[Will]

I think part of the confusion is a misunderstanding of terms. In formal logic, there are statements and there are theorems. A statement can be proven false by a single counter-example (which in turn usually means a flaw in logical reasoning to arrive at that statement, or false premises). A theorem is a collection of statements, which counter-examples do not disprove; a counter-example to a theorem merely shows that the theorem is incomplete. It is much more difficult to disprove a theorem, because you need to prove false ALL the statements in the theorem, not just a few. I didn't do much to help in the confusion since I took your example of the algebra equation (normally a statement) and pretended it was part of a model or theorem, when I said it is still right for y=1.

I really would like to understand your reasoning, but from everything you've said, I can only conclude that you haven't had much experience in the hard sciences. It is fine to question theorems to gain a better understanding of them, but to just reject them out of hand you really do need to present an alternative. Otherwise, you are just an admitted novice that is rejecting the claims of experts in a field just because you don't like some of the evidence. That isn't science, that is dogma. Even the articles you linked do very little to the theory as a whole; the author of the Technology Review article claims to still think that human action has caused a rise in global average temperature. The Marshall paper basically says that the 90's was the warmest decade in the approx. 140 year direct temperature record, and held the position that indirect temperature estimates for before 1860 are incomplete in that it only takes into account local temperature (meaning, they want a more widespread and comprehensive study, eliminating as many assumptions as possible from the data analysis). Both basically say we need more information to refine our understanding of human impact, but neither one comes anywhere close to denying human impact. For both, the prevailing theory of global warming still holds.

Anyway, this isn't really a bandwagon issue. Most climatologists say that there is global warming because the data fits, and all competing theories (sunspot cycles, 20th century as end of the ice age, etc.) don't fit the data as well. The best fit model wins, and it has survived quite a bit of scrutiny in the 80s and 90s. After all that scrutiny, it is only natural that the experts would come to accept it as the best current theory.