“What, then, is the future of the $5 trillion global oil and gas industry that supplies almost 60 percent of world energy? The industry will continue to need to find and develop another three to five billion barrels a year just to make up for the natural decline in oil fields, which happens after a field has been in production for some time. The International Energy Agency estimates that over $20 trillion of investment in oil and gas development will be required over the next two decades.”