Humankind’s overshoot condition will naturally reduce itself this century. Most of the world's 7 billion persons will starve to death, die in conflict or succumb to disease. Much of the eco system’s will lose its productivity or become toxic.
Faced with this view of the future. I can think of two proactive human behaviors that can adequately reduce the overshoot and prevent this tragedy.
I am focused on the communication that will implement limiting the number of births. I see a democratic process implementing that limit through enactment of civil law; The process is similar to the law that abolished slavery. That is, a majority of the global population thinks the law is necessary to produce desirable living conditions. Even if this means, removing some personal freedoms which have been previously accepted as inalienable.
The needed communication, that creates this constituency, is what is said to one person that brings him or her
Yes there are many political and social means for obtaining these votes. But, initially, if we cannot succeed in getting one person to change their view of humankind's predicament and change his or her view of what changes unwind it, we probably cannot get the political and social forces to aid us in creating this new law.