Consider all the actions possible tomorrow, which individuals or groups could take. Are there any which would "obviously" (meaning: you believe it with high probability, and you expect that belief to be uncontroversial) result in decreased x-risk?
(For example, consider reducing the size of Russia and the US's nuclear stockpiles. I'm curious if this is on the list.)
(I include "which individuals or groups" could take because I am interested in what actions we could take if we all coordinated perfectly. For example, neither Russia nor the US can unilaterally reduce both their stockpiles, and perhaps it would increase x-risk for one of them to lower only theirs, but the group consisting of US and Russia's government could theoretically agree to lower both stockpiles.)
I'd suggest work that would allow vaccines to be developed much more quickly falls into this category - it was mentioned in the 80,000 Hours podcast with Tom Kalil.
"I was able to get some additional funding for this new approach [to develop vaccines more quickly] and my primary motivation for it was, maybe it’ll help in Ebola, but almost certainly if it works it will improve our ability to respond to future emerging infectious diseases, or maybe even a world of engineered pathogens."
https://80000hours.org/podcast/episodes/tom-kalil-government-careers/
Again, I disagree this is obvious. Just some ways in which this could be negative: