Comment by inaros

For starters "Terraforming Mars" is not a prominent feature of Musk's Mars plans. He's repeatedly stated that it's possible to do so, but the things he's consistently said he wants to do are to establish a Mars colony and turn it self-sufficient. Then maybe terraforming as a long-term goal, but the success of his mars colony does not depend on terraforming at all.

On his whole "if you can terraforming Mars, you can terraforming Earth" I would remind you that Musk's ideas for terraforming Mars include "let's nuke the poles", "we could heat the soil to release more CO2" and "after releasing a lot of CO2, we could electrolyze the water in the ice caps to get oxygen". The challenges for reversing global warming on Earth and terraforming Mars are almost polar opposites

deGrasse's most reasonable point is that the ROI of the whole Mars plan is terrible. Probably not zero (selling flights and accommodations for tourists and science institutes is the easy one). But Musk has said he does not want to finance the Mars plan with VC money, for the exact reasons deGrasse is pointing out. Musk's claim isn't that he's doing it because it's profitable but because it's "geopolitically expedient" as deGrasse puts it. How this squares with the recent news of a SpaceX IPO I don't know, but that wasn't a factor back in 2024