Regarding “the problem of human existence”, it sounds like you’d get along with the people at the Voluntary Human Extinction Movement. I have no reason to think that organization is particularly effective at achieving its goal, but they might be able to point you in the right direction. There’s also Population Connection, which I don’t believe shares the same end goal but may (or may not) be taking more effective steps in the same direction.
Regarding “the problem of human existence”, it sounds like you’d get along with the people at the Voluntary Human Extinction Movement. I have no reason to think that organization is particularly effective at achieving its goal, but they might be able to point you in the right direction. There’s also Population Connection, which I don’t believe shares the same end goal but may (or may not) be taking more effective steps in the same direction.