I'm just as clueless. I think there are three syllogisms that tech brains orbit around.
AI will improve society, a better society would face climate change more effectively, so AI will help us face climate change.
Basically an extension of the milder claims with regards to AI improving education, health care, research, the economy, etc.
Very vague and feel-good and I think more a reaction to distrust of AI than an assertion of anything.
AI will help us better understand complex systems like climate, understanding the complexity of climate change helps us, so AI will help us face climate change.
Stemming from skepticism of current climate science methodology that doesn't fit with what they think science should be.
Secretly hope that AI will show us climate change isn't actually even real and the fact we think it is is some byproduct of our feeble minds trying to understand something so dynamic and complex.
There's some magic bullet technological solution to climate change that is outside of current human ability space to invent. AI can potentially eclipse these limits and invent things we can't. So AI can invent this magic solution.
Hardcore AI singularity takeoff yadda yadda folks. Goes hand in hand with the ideas AI will invent microorganisms or nanobots that will take over the entire biosphere or thinking it will find a new theory of physics that lets it teleport places or shit like that.
In this POV climate is even a non-issue since AI could easily solve it but we can't easily solve how to not make this AI kill us.