The problem with the Green New Deal is that they tacked a large amount of stuff on there that has nothing to do with climate change, and are things that actually work against the stated goals. Free college, increasing medical services and increasing wages are all things that, while nice, drive the standard of living up thus making the USA and even more energy-hungry place than it is already. Livable wage = increased resource consumption. Even the poorest Americans (barring homelessness which is much driven by mental illness, addiction) have a standard of living that would be considered comfortable middle class in much of the world, so the GND livable wage really means livable compared to the more relatively well-off Americans not compared to how the average schmuck lives globally, and that goal would specifically increase demands for energy, food, resources, in the USA.
Especially the whole 'free college' thing. Putting that in is like a hand-grenade you put in on purpose to make sure that nobody will actually support your bill, and you can claim the moral highground while not having to actually deliver. It's not something you include in your bill if you realistically want it to be passed.
And the 'free college' proviso in the GND is literally holding the environment to ransom to get everything you want. Sure, it's a reasonable thing to fight for, by itself, but it's not reasonable to tack that on as a non-negotiable on an environmental protection bill then accuse the other side (and people on your own side you wish to replace with your own brand of Pod People) of malfeasance for not supporting the whole thing. If the claim is, rightly, that it's desperate that we pass environmental protection bills ASAP then it makes no sense to put things in there which are basically ultimatums of the scale of the Austrian WWI ultimatums to Serbia, deliberately going too far to actually get passed. In this respect, the GND isn't a realistic thing that was supposed to get passed, it was a Cassus Belli against the mainstream to push radleft economics by dressing them up as an environment issue. Sure, fight for those things, but don't tack them onto an environment bill then claim everyone else is against the environment when the bill doesn't pass.