[mempko]

Available energy is a limiting factor in economic growth. More available energy allows for more economic growth. While a decline in economic growth for other reasons (financial crisis, pandemic) reduces demand for energy. So it's both a cause and effect. It's a feedback loop! Asking it it's causation or correlation is the wrong question. Does the temperature in the room effect the thermostat, or the thermostat effects the temperature in the room? It's a feedback loop!

In other words, when potential economic growth buds up against energy supply, energy prices rise and they rise non-linearly. This causes a reduction in potential economic growth. If there is a decline in economic growth, then demand falls below supply and prices drop. As prices drop they enable more economic growth.

In other words, the economy grows as much as energy supply allows. A 10% decline in available energy means a 10% decline in GDP. It really is that linear.