I feel this is an egg & chicken situation. Solarpunk wasn't much of a genre until renewables became advanced & more widespread enough and the vision is very much based on us expanding hugely on renewables and becoming more ecologically conscious. This is, in the broader scheme, very much the goal of where we should head towards to reach climate neutrality. So in that sense it is as serious as the climate scientists advocating for it, even if not by name but simply by what it entails.