You could say this about any pov that discourages any behavior: "Dead people don't murder, and so the movement to stop murder can be traced directly to Neomalthusian and eugenicists."
It's obnoxious to exaggerate the perspective of people you disagree with, just to make them seem less reasonable. Those who want people to decrease their carbon footprint don't want you dead, they just want people to decrease their carbon footprint.
This response is more insulting than it needs to be. There's nothing amazing about thinking that in order to solve a hard problem, you need to do a hard thing. Whether or not implementing political change is a necessary first step to solving climate change has nothing to do with whether implementing political change is hard or even impossible. It's absolutely plausible that there's no way to solve climate change without systemic change. It's also plausible that we can't solve climate change without systemic change AND that systemic change is very hard or even impossible. These statements aren't contradictory. In addition, tying the suggestion to a political party and then calling it stupid is not a constructive form of discourse.
It's obnoxious to exaggerate the perspective of people you disagree with, just to make them seem less reasonable. Those who want people to decrease their carbon footprint don't want you dead, they just want people to decrease their carbon footprint.