What a ridiculous article... everyone understands that exponential growth cannot continue forever. The bigger and more interesting question is what the life of an average human looks like when growth inevitable slows down, and how fast we can get there.

Because the assumption that we will grow our energy use indefinitely is flawed. Energy use has diminishing returns, eventually we'll run out of useful work we want to perform. At least in terms of material wealth and comfort.

There's probably also major opportunities for energy savings that extends this timeframe greatly. Incandescent -> LED lights have reduced energy consumption by a factor of 10. Technology improvements in just the last 5 years have halved the energy consumption of air conditioners.