Her argument for being vocal is that her and her generation will have to live with the consequences of our fuckups the longest and hardest. I think that’s pretty valid. Also, she wasn’t “elected by the central climate movement council to be their representative”, if anyone, the media “elected” her and gave her a platform. So maybe be mad at them for not choosing someone “better”?
There are plenty of old white men with respectable titles saying the exact same thing as her. If a “climate change laggard” wants to hear the same message in a deeper voice, they certainly can. For those who can be moved to action at all (and there are definitely many who are “too far gone” in some conspiracy bullshit) she can be effective for many, especially younger people who have to be shaken from their stupor. So I think it’s a bit critical to “tell the girl to shut up”.