If i ruled the world, the first thing I'd do is prevent global warming and arm trade in the developing world.In my opinion, that's one of the most serious problems we face.I believe we could stop this problem.
The next thing I'd do is make governments invest in solar power and make machines that work on this power.
There are some less serious things I'd do to.I'd ban cars that ride on oil and I would increase payment and put down prices.Finally,I'd ban alckohol and smoking and drugs.