(I move the socialism/humanism topic here)
It is true that Milton Friedman did not mention the climate issue (IMO, as many other issues). It can lead to the rebuttal that, for him and his followers (I think this critic is also valid for Deirdre McCloskey), “all is about economics”.
This is why I believe, we need to inscribe the free-market theory in the larger framework of secular humanism (as defined by CFI). I believe all is about philosophy.
What follows is only intended as an overview of what I know about the relation of classical liberalism with the climate issue.
From what I know, classical liberals, as of today, take the climate issue quite seriously. Maybe worth it to precise that I know of no classical liberal who is a climate change denier.
The points I heard until now in today’s classical liberalism movement about climate change:
(1) They will point to optimists books such as Ten global trends every smart person should know (Bailey and Tupy, 2020), The Rational Optimist: How Prosperity Evolves (Matt Ridley, 2010), the work of statistician Hans Rosling, and projects such as Human Progress (by the Cato Institute)
(2) They consider that the industrial society framework freed human beings from misery, while the environmentalists tend to hold an idealistic, irrealist view of nature, in the flavor of the romantic Rousseau. They hold that environmentalists reject the most credible solutions to the climate issue, due to their anti-modern romantic position, while it is the technique brought by the industrial society framework which does provide these most credible solutions to the climate issue. (see Les Ecologistes contre la modernité, Ferghane Azihari, 2021)
(3) Trigger warning, the following line can hurt sensibilities: Some more conservative liberals[1] often use the “watermelon” parabola to describe the most radical environmentalists ideology (i.e. green on the outside, red on the inside)
[1] As I indicated elsewhere, I believe “liberal conservatism” is the greatest adversay to “liberal humanism”