I wrote a blog called "Should Humanity Continue to Exist," where I said climate change is the best way to make humans extinct. But it's a slow process and takes a lot of time. As for nuclear wars, we don't know if they'll happen or not. So, I'm asking for a better, faster method that individuals can implement.
I know anti-natalism could be a better option, but it's hard to persuade people to stop having children.