If you could time travel, what would you change ?

Global temperatures are inevitably rising due to climate change. Scorching temperatures to become normalcy in the next years. Microplastics (due to pollution) everywhere, even inside our brains. More and more species becoming extinct, disrupting the food web. I could stop here, but I must continue: digital dystopias becoming true, like 247 surveillance and AIs everywhere (even though I like artificial intelligence to a certain point). Increasing prices worldwide, increasing professional competition while there's a grow of ghost/fake job vacancies. Political polarization and extremisms, rising of bigotry. Increasing homelessness while there's an increase of hostile architecture and growing rental prices. Sorry, but it doesn't seems like everyone is really having the right to live a healthy and happy life...