@adamgreenfield honestly speaking, I don't know if "The Ministry of Sustainability" is doable as a single book; looking at all the angles and levels of the changes needed. I could imagine it as a series, maybe even as some mega-anthology from multiple authors?
My take on solarpunk and climate fiction is to first see the uncomfortable things we don't want to see, so I could "cover" some activism, hard open data problems and so on, but would ask someone else to tackle the scientific parts.
@adamgreenfield one way or another, I think that striving for a Single Climate Masterpiece might always pull us in the direction of too elegant, too pure, ignoring some really important parts of the world and problems to come.
That also means that "consuming" climate fiction might be different, potentially harder than reading science fiction, since the reader would need to do a lot more emotional and intellectual work.