Fuck AI

Externalities exist in all systems. Im not sure why you are mentioning them in this case given they are not unique.

I bring them up because they demonstrate my point. Externalities need to be taxed because profit is the only need markets respond to, which was my point.

The reality is markets respond much more rapidly and accurately than planned economies can. This might change if AI becomes a reality but right now planned economies will continue to be less efficient.

Only using a contorted definition of efficiency that favors markets, namely maximizing GDP. It does not speak to the efficiency of throwing away food, cutting up old clothes, letting people die from curable illness, or to reiterate the point, making the only planet we've ever seen sustain life unsuitable for us because it's simply impossible to convince market economies to seek anything other than profit.

Not really and again it isn’t as if environmentalism has been the focus of the Marxist states IRL either. The USSR was devastating to their environment.

Agreed, the USSR was also going through rapid industrialization. The difference is market economies have an absolute global hegemon, and still cannot meaningfully address the reality of climate change because it would effect profits.