b_b posed a similar question 1160 days ago. https://hubski.com/pub?id=15752 Dendrophobe, you may enjoy some of the responses. scarp thought that we'd be judged by how much money/resources we spend on military vs science and that we all drove cars that "ran on fossil fuels and pumped out poisonous gases from the rear." scrimetime was succinct, as usual, and said, "Our education system. There has to be a better way for something so incredibly important to our future." -I agree with him. Anyways, some good conversation in that old post. Check it out.
And, if we haven't managed to do this, I'll say the Cold War and the continuing effects (esp. on the Mid. East), religious intolerance still leading to violence (we haven't come very far since the crusades, apparently), and in America specifically, our persecution and segregation of homosexuals in some parts of the country.