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.)
While I'm sympathetic to this view (since I held it for much of my life), I have also learned that there are very significant risks to developing this capacity naively.
To my knowledge, one of the first people to talk publicly about this was Carl Sagan, who discussed this in his television show Cosmos (1980), and in these publications:
Harris, A., Canavan, G., Sagan, C. and Ostro, S., 1994. The Deflection Dilemma: Use Vs. Misuse of Technologies for Avoiding Interplanetary Collision Hazards.
Ben's summary:
Sagan, C. and Ostro, S.J., 1994. Dangers of asteroid deflection. Nature, 368(6471), p.501.
Sagan, C., 1992. Between enemies. Bulletin of the Atomic Scientists, 48(4), p.24.
Sagan, C. and Ostro, S.J., 1994. Long-range consequences of interplanetary collisions. Issues in Science and Technology, 10(4), pp.67-72.
Two interesting quotes from the last one:
More recently, my collaborator Kyle Laskowski and I have reviewed the relevant technologies (and likely incentives) and have come to a somewhat similar position, which I would summarize as: the advent of asteroid manipulation technologies exposes humanity to catastrophic risk; if left ungoverned, these technologies would open the door to existential risk. If governed, this risk can be reduced to essentially zero. (However, other approaches, such as differential technological development and differential engineering projects do not seem capable of entirely closing off this risk. Governance seems to be crucial.)
So, we presented a poster at EAG 2019 SF: Governing the Emerging Risk Posed By Asteroid Manipulation Technologies where we summarized these ideas. We're currently expanding this into a paper. If anyone is keenly interested in this topic, reach out to us (contact info is on poster).