There has never been one. From 1800 to 1900, per capita energy consumption, primarily from biomass, remained relatively flat; as did the average life expectancy. From 1900 to 1978, per capita energy consumption roughly tripled with the rapid growth in fossil fuel production (coal, oil & gas). This was accompanied by a doubling of average life expectancy. While I can’t say that fossil fuels caused the increase in life expectancy, I can unequivocally state that everything that enabled the increase in life expectancy wouldn’t have existed or happened without fossil fuels, particularly petroleum.

Our modern society would not exist without fossil fuels and it would collapse in a heartbeat if fossil fuels were made unavailable and/or unaffordable. One of the coolest things about being a petroleum geologist, is that I can give thanks for fossil fuels and say “you’re welcome” in the same sentence.