A motivating scenario could be: imagine you are trying to provide examples to help convince a skeptical friend that it is in fact possible to positively change the long-run future by actively seeking and pursuing opportunities to reduce existential risk.
Examples of things that are kind of close but miss the mark
There are probably decent historical examples where people reduced existential risk but where thoes people didn’t really have longtermist-EA-type motivations (maybe more “generally wanting to do good” plus “in the right place at the right time”)
There are probably meta-level things that longtermist EA community members can take credit for (e.g. “get lots of people to think seriously about reducing x risk”), but these aren’t very object-level or concrete
The CLTR Future Proof report has influenced UK government policy at the highest levels.
E.g. The UK “National AI Strategy ends with a section on AGI risk, and says that the Office for AI should pay attention to this.
I think that working out how resilient food technologies could be scaled up in a catastrophe such as nuclear winter is legible and concrete, including natural gas (methane) protein, hydrogen protein, greenhouses, seaweed, leaf protein concentrate, fat from petroleum, relocating cool tolerant crops, etc. Indeed, a survey and a poll have indicated that this work has reduced existential risk.
If you think the UN matters, then this seems good:
https://forum.effectivealtruism.org/posts/Fwu2SLKeM5h5v95ww/major-un-report-discusses-existential-risk-and-future