Speculation is important for forecasting; it's also fun. Speculation is usually conveyed in two forms: in the form of an argument, or encapsulated in fiction; each has their advantages, but both tend to be time-consuming. Presenting speculation in the form of an argument involves researching relevant background and formulating logical arguments. Presenting speculation in the form of fiction requires world-building and storytelling skills, but it can quickly give the reader an impression of the "big picture" implications of the speculation; this can be more effective at establishing the "emotional plausibility" of the speculation.
I suggest a storytelling medium which can combine attributes of both arguments and fiction, but requires less work than either. That is the "wikipedia article from the future." Fiction written by inexperienced sci-fi writers tends to generate into a speculative encyclopedia anyways--why not just admit that you want to write an encyclopedia in the first place? Post your "Wikipedia articles from the future" below.
As a side note, thank you snarles! This really was a neat exercise, because as an inexperienced writer who likes writing, this gives me the fictional idea of "United States v. Windsor, polymarriage version" where an older altruist polygroup is suing the United States federal government to legalize polymarriage because one of their members died and because of the lack of tax benefits, means would be losing hundreds of thousands of dollars that they could be giving to save the lives of poor people, so OF COURSE they're fighting it in court because lives are at stake and it doesn't matter to them that those lives are far.