I always had the interest to write a Future Timeline where, by the 2150s, almost everything went wrong for the world; a break between Europe and the US, a limited WWIII over the melted Arctic passage, a collapse of the global economy and famines as a result of degraded arable farmlands, and overall worse and worse climate change forcing rather liberal countries adopting more and more autocratic features with Europe, for example, practically becoming a collection of de-facto military juntas. China embraces totalitarianism to its greatest extent thanks to improving supervision technologies and the senate and congress of the USA practically being in a constant deadlock over most affairs, with the country itself resembling more and more a corporate dystopia. The Middle East, after the end of commercial oil, fails to lift off into a post-oil economy and falls into a great war which had been building up for decades, ending with an (extremely limited) nuclear exchange. Overall, the world is in a constant cold war between the EU, the US, and the PRC over the Arctic passage, spheres of influences, orbital weapons and mining rights on the moon and beyond.
It's not supposed to be hyperrealistic, but I always thought it would be a fun timeline to write and read, but I think it would gather enough attention to make extensive writing worthwhile.
Note: the black areas are inhabited, but do not necessarily resemble some sort of anarchic state within the region, but rather such a complete collapse of authority that communalism and warlordism emerged victorious in these areas.