I’d change the human evolutionary past to make them better able to understand the impact of their actions on others. In broad terms, humans have evolved to look after a small group of people that they feel loyalty to (your family, your nationality, or your religious group). This means that, as long as our immediate group is not affected, we don’t worry about hurting others or future generations. This leads us to use up resources like water that others need much more, blowing CO2 into the atmosphere, or buying things that we know other people don’t get properly paid for. We all simply don’t think of this because our brains haven’t evolved to cope with it – I’d love to change that.
My answer is sort of similar to Vera. If I could wave a magic wand, I would get rid of disease, and ensure that there were enough resources for everyone to live happily with no suffering. I would also probably limit our reproductive rate so the earth doesn’t become (even more) overpopulated.
But without a magic wand, many of these changes could be achieved simply by redistributing wealth from the very rich people (in countries like the UK) to the desperately poor in much of the world. I would like to see that happen.
I would just like to remove all war from the planet, and have people just get along and share. I would certainly have everyone equal, so that everyone has the same chances in life. The whole money-grabbing culture we have would also go. I’d like to see people value what is really important, such as each other and the world we share than numbers in a bank of small pieces of transition metals.