What changed in early 1970s is the energy crisis. Economic growth before 1973 was about finding new ways to burn more and more fossil fuels to make stuff: US GD

What changed in early 1970s is the energy crisis. Economic growth before 1973 was about finding new ways to burn more and more fossil fuels to make stuff: US GDP increased 2.1x between 1953 and 1973 while final energy consumption increased 2.01x, barely any improvement in energy efficiency (4.5% in 20 years). Between 2001 and 2021, GDP indeed grew less, by only 46.5%, but energy consumption grew by only 1.8%, resulting in 44% growth in energy efficiency. Same trend is the case worldwide. Progress is slow because we have moved from extensive to intensive economy, learning how to do more with less.