Ask HN: How can AI/ML save the world?

I'm currently looking for a PhD topic that could have a positive impact in the world. I'm having in mind to find ways to contribute to the sustainable goals defined by the UN (see https://www.un.org/sustainabledevelopment/sustainable-development-goals/).

Do you have suggestions of projects where the latest knowledge in ML/AI could make a major change on the climate (Goal 13) or to improve the life below water/on land (Goals 14, 15)?

Thanks