I definitely don’t agree with that take.

First of all, “terraforming” means “to make Earth-like”; climate mitigation is one thing, but if we let things here get bad enough that we have to start thinking about terraforming Terra, we’ve pretty thoroughly screwed the pooch at that point. Ending up with an Earth that is no longer Earth-like would mean that things have gone sideways so badly that I doubt we’d have the industrial capacity or resources to deal with it.

Second, terraforming Mars involves a vastly different process than unfucking our climate and ecosystems. For example, Mars has a very thin atmosphere, which on top of being thin is mostly CO² and doesn’t have more than trace amounts of oxygen. There’s also no magnetosphere to speak of because its “core dynamo” essentially died when its core cooled down and plate tectonics etc stopped being a thing, meaning that any atmosphere you do manage to generate is continuously getting blasted away by radiation.

Terraforming Mars essentially means pumping more energy and gases into its climate system via whetever method, while the problem here on Earth is that we’ve pumped too much energy into the climate system and we’d have to somehow get it “out” again.