AGW skeptics assert that human greenhouse gases have no effect on global climate.
If it is a faith-based assertion, there is nothing that will change their mind.
If on the other hand, they view it as a factual assertion, then it it is a statement in the scientific arena, and must therefore be capable of being refuted.
They agree that CO2 is a greenhouse gas, that is, that it traps infra red radiation, since this is a physical fact.
They agree that concentrations have risen since the Industrial Revolution, since that is an observed fact.
They accept that global temperatures are rising, since they often say that "climate change is happening, it happens all the time, due to natural variation".
So their case is that although CO2 is a greenhouse gas, and is rising, it makes no contribution to the rise in temperature. Or maybe they mean it makes a negligible contribution.
But the climate models say that it is making a significant contribution.
So they reject the use of climate models out of hand, rather than agreeing that they are, like all machines, a useful but imperfect instrument.
It is impossible accurately to study a complex system as the atmosphere without models.
Therefore there is nothing that will convince them that they are wrong.
Therefore their case is not a scientific case, because science must always be falsifiable.
What this leads to is that just as they accuse us of having an ideological agenda, so also do they have an ideological agenda.
It goes like this:
"I believe in individualism. My prime responsibility is to Me as No 1, also my family if I so choose. I will look after my own interests in my own way, and Government should get out of my face and my backyard. There is no such thing as society. I am not responsible for what happens to others, if bad things happen to them, that is there look out. Sh*t happens.
Individualism demands free market fundamentalism. Individualism means that corporations, which are individual persons in law, must not be subject to any regulation, because the Invisible Hand of the Market will produce the best of all possible worlds.
If global warming were true, it would be necessary for representatives of the people to intervene in the market to make carbon pay for the damage it does.
I reject any intervention in the market.
Therefore I reject the idea man-made global warming.
Nothing will induce me to change my mind on this point, because I am an individualist".