I would reduce the deforestation and help people get more practical education especially in poor and violent areas where kids are forced to take jobs because they don't get proper education, practical education in the sense making them learn about Cryptcurrency and Bitcoins, getting them hands-on internship etc, I think education for knowledge to earn money is way out of poverty which is one of the black-mark in our society, would love to get your opinions and thoughts on how you would impact the world when you are a billionaire.