Olduvai theory: "The theory is easy. It states that the life expectancy of Industrial Civilization is less than or equal to 100 years: 1930-2030. World energy production per capita from 1945 to 1973 grew at a breakneck speed of 3.45 %/year. Next from 1973 to the all-time peak in 1979, it slowed to a sluggish 0.64 %/year. Then suddenly —and for the first time in history — energy production per capita took a long-term decline of 0.33 %/year from 1979 to 1999. The Olduvai theory explains the 1979 peak and the subsequent decline. More to the point, it says that energy production per capita will fall to its 1930 value by 2030, thus giving Industrial Civilization a lifetime of less than or equal to 100 years."

Olduvai theory: "The theory is easy. It states that the life expectancy of Industrial Civilization is less than or equal to 100 years: 1930-2030. World energy production per capita from 1945 to 1973 grew at a breakneck speed of 3.45 %/year. Next from 1973 to the all-time peak in 1979, it slowed to a sluggish 0.64 %/year. Then suddenly —and for the first time in history — energy production per capita took a long-term decline of 0.33 %/year from 1979 to 1999. The Olduvai theory explains the 1979 peak and the subsequent decline. More to the point, it says that energy production per capita will fall to its 1930 value by 2030, thus giving Industrial Civilization a lifetime of less than or equal to 100 years."