In the 1990s Simmons annoyed many members of the oil patch by questioning conventional group think in the industry. When energy gurus predicted oil demand would not grow beyond 60 million barrels a day, Simmons warned that demand was growing too rapidly as it crossed 70 million barrels by 1995. When the gurus said that oil supplies would endlessly surge, Simmons documented the steady depletion of oil fields in the North Sea and Middle East.
Realizing all was not well in the energy world in 2002, Simmons reread The Club of Rome's report The Limits To Growth. Since its publication in 1972 traditional economists had trashed the report as a "doomsday book." But in his revisit Simmons found a sober account of how exponential growth and unbridled energy consumption would lead to constraints or a decline in industrial activity by 2050.
"In hindsight," he said, "The Club of Rome turned out to be right. We simply wasted 30 important years by ignoring this work."