Energy is the only universal currency: one of its many forms must be transformed to another in order for stars to shine, planets to rotate, plants to grow, and civilizations to evolve.

Vaclav Smil

The food we eat. Coal we burn. Crude oil we burn. Crude oil we make into plastic. Crude oil we use to make chemicals. Natural gas we use to make fertilisers. Coking coal we use to make steel. Crude oil we use to operate vehicles to mine metals and other materials.

All are transactions to convert energy into other forms. Or to produce goods. Things we actually use to tangibly improve quality of life and improve our odds of survival.

Time and energy are the only real currencies. And we can manipulate them by only so much. We can become more efficient at using energy. Or we can be smarter with our time.

But that we have to learn to put a better value on those two actually finite sources (unlike seemingly infinite Fiat currency) looks inevitable.