Jeff Gray:

It is easy to get blinded by large numbers, but *trillions* of dollars over 50 years over billions of people is not very much -- just $20 per person per year or so. It is not surprising that this hasn't industrialised the rest of the world over that period of time. It is an enormous problem and even if tackled very efficiently, it will take trillions more before the gap closes. I strongly suggest using 'dollars per person per year' as the unit to see the relative scales of things.