Energy return on investment is declining

The energy return on investment is decreasing, shrinking the excess energy available per person; oil discovery illustrates this—in 1919 one barrel of oil found another 1000 barrels, by 1951 only 100, and by 2010 only 5—and since roughly 50% of GDP growth comes from energy and 50% from innovation/efficiency, this decline drives a return toward a Malthusian, scarcity-driven world.