The current best supported theory is that the earth is in a natural cooling stretch or mode of the "cycle", which is being overridden by an unprecedented boost in atmospheric CO2 and associated "greenhouse" gases. - - - - - You can't change reality by naming it wrong. An argument ad hominem is an invalid form of argument against the message, not the messenger. It is an attempt to argue against the message by irrelevantly impugning the messenger, personally - and that is granting you the deflection "messenger", when we are actually dealing with paid liars and propaganda. What you and your American political faction have been labeling "ad hominem" is instead a variety of other things. Most aren't arguments at all, against anything, but instead simply denigrations and insults or labels you find insulting (such as, comically enough, "Republican") - public derision of the person, regardless of the thesis. Some - not many - are at least arguments, but they are arguments against the person rather than their argument or assertion - against taking the person as a source of facts, assessments, or even simple accuracy of assertion. These are not ad hominem arguments, because their impugning etc is directly relevant to the argument against the person they make. To repeat two examples: 1)That would be the case in the automatic dismissal of all sources of AGW denial that are funded by Exxon and/or involve "scientists" who have no expertise in the field. Note: not their arguments or assertions. Those are not involved. So that is not an ad hominem argument. (We know that Exxon did fund some genuine research, verified for themselves that AGW was real and overwhelmingly significant, and secretly used those findings to guide their own business plans while simultaneously promoting public denial of AGW by bribed "scientists" of proven cupidity and no relevant expertise. ) ; or, thread relevant, the professional fixers hired by the Republican administration and its financial backers to deceive the public about the Mueller report (Barr, pre-eminently). 2) That would be the case in accurately identifying Barr as a professional fixer hired to deceive the gullible and conceal perfidy. That is not an ad hominem argument or part of one, but a legitimate ground for dismissing Barr and whatever he says (not anything in particular) from any honest discussion about the Mueller report or anything else. He could even be making true and relevant assertions or arguments (in theory), and still should be dismissed from any honest discussion on those grounds - the naming of his role is part of an argument against the "messenger", not the "message". And so it is not an ad hominem argument. - - - - But not useful and significant responses to AGW, attempts to slow it down and ameliorate its effects, to restore in part the ability of organisms (including people) to adjust as they have adjusted in the past to the much slower and smaller natural cycles. Those are suppressed by greed, hypocrisy, and organized propaganda campaigns of lies and deceptions designed to support that greed and hypocrisy by creating bafflement and misplaced anger in US political discourse.