1st get rid if the elitist that manage the world with the only interest of profit. (bankers, politicians, top 1% wathever you call them)
2nd, get a new political class (after a "intelectual revolution") that adress the real problems of the world, more as the human race as a hole than individual countries with useless nationalism.
3 enact laws that are strictly persecuted so we can reduce world population peacfully in a few generations. enable abortion, no more than 1 son per family etc.
4 make the life controlled by laws si resources so we dont waste resources and human life is sustainable.
5 reach a stable population to mantain a faily good standart of living, if possible a lot more equally distributed
we have 50 years or we are all going to die horribly . we or our children
