Every time I wrote that economic concerns do not matter in a world where the economy has collapsed along with civilization in an eco collapse, I have made this argument.

This is exactly the point. Consider it a sort of pascal’s wager. If, I am wrong, worst case is we waste money. If I am right worst case is money and civilization as we know it disappears in the wake of hundreds of millions of deaths, spread of contagion, starvation and war - not to mention our coastal cities.

But it is not just a 50/50 in the row thinking. It’s not even close.

There is no possibility at all that CO2 is not a GHG.

None

The best possible flaw in the science for the deniers would be that something else has a bigger effect. This is actually much much worse, because if that were the case, then there would be nothing we could do to prevent the collapse.

Fortunately, as in thank God, no such thing has been detected. That means we have a chance to do something about it. Further, even something else were a bigger effect, the extra CO2 still must do its thing. Just like water must turn to ice if it gets cold enough, CO2 trapping IR is just a property of the material. That is just the way it is.

When people say that nothing is ever settled in science, it is a deeply disingenuous stance. Eventually enough evidence accumulates that things are settled. Now as a scientist, what I mean by settled is that on order for the picture to be different, everything else we have seen to be true, that was predicted by the first picture must also be explained by some new thing - and the odds of such a new thing even being possible become vanishingly small.

A great example of settled science is the notion that the Earth is round. Think of all the different ways we have observed it’s roundness. We see it as round from orbit. We can even have those orbits because it is round. We call people in Japan and it is dark there during the day here. And on and on. How could all of those things still be true, and yet somehow the Earth is not round.

The science is just as settled with relativity and evolution and QM

QM tells us that CO2 must absorb IR.

So the point is, there is no 50 50 in the row thinking at all.