If I were a god I would not solve any problems. I am a lazy god after all. Rather I might empower mortals to resolve their own issues. My first change would

If I were a god I would not solve any problems. I am a lazy god after all. Rather I might empower mortals to resolve their own issues. My first change would be to universally speed up the intellectual evolution so that they might see the errors in their ways sooner. At the same time I might improve their endocrine system so that the increased intelligence does not lead to significant spikes in depression. No, I am not making them into Dr. Spock. Just enough control so that the rational mind is more dominant. Oh and being a god with a sense of humor and given that you want me to work, I might turn things around in the food chain just a smidge and teach deer how to form a pack and hunt their predators.