@mollythemeerkat
Find the truth - what seems to be happening is that local Green Party councillors are trying to effect change in small ways, supporting green transport for instance, encouraging councils to give up pension funding with carbon producing companies, banning pesticide use on public land etc, but the National party HQ seems to be another thing altogether. I`m interested in your comment secular re class - Greens, I think, have always been viewed as white and middle class, but they had good economic policies too, wealth tax, universal basic income for example, increasing minium wage and so on, but those never got much attention. Maybe the issue was: "Oh well, they can say what they like when they have no chance of getting into power". And that book does sound interesting.
Robinson, in another of his books, refers to this time - the early decades of the 21st century, as 'The Years of Dithering'. That is, the period when the climate crisis was recognised, but simply was actioned-upon with any serious intent.
And XR and the English and Scottish Green Parties are absolutely intent on being associated with The Years of Dithering. As a global climate change protest organisation, XR might as well be led by Donald Trump for all the good it contributes. Indeed I do wonder, in conspiracy theory terms, if XR isn't actually a CIA front organisation, determined to ensure the worlds polluters and its moribund politicians (such as say, those in the US and particularly China) get a 'bye' and are left alone from having to contemplate a genuine action plan to combat climate change. I doubt history will be kind to XR and the English and Scottish Greens.
Whilst The Greens might have some useful input at the local level (I've never seen any, and my ward has a Green councillor) there's an unintended impression that The Greens in 'the Shires' are a bit simple and can't use the Internet to figure-out that their national leadership are, well, bonkers. Certainly the members in The Provinces keep on voting the daft ones in.