It is doable. We can't use nuclear weapons, because that would destroy the environment..

So perhaps use a specially designed chemical weapon to wipe out the populations of China, India, European Russia, major parts of Africa , Texas and California and some of Europe.. Leave the Aussies, because they're far away anyway..

The World government should be establised at "Stonehenge" in the UK - This is viable, because most of the UK has moved away from religion anyway..

I am ready to assume the mantle of Supreme Leader, till things normalize..